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Physical Activity and Sports—Real Health Benefits: A Review with Insight into the Public Health of Sweden

Christer malm.

1 Sports Medicine Unit, Department of Community Medicine and Rehabilitation, Umeå University, 901 87 Umeå, Sweden; [email protected]

Johan Jakobsson

Andreas isaksson.

2 Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Solna, Sweden; [email protected]

Positive effects from sports are achieved primarily through physical activity, but secondary effects bring health benefits such as psychosocial and personal development and less alcohol consumption. Negative effects, such as the risk of failure, injuries, eating disorders, and burnout, are also apparent. Because physical activity is increasingly conducted in an organized manner, sport’s role in society has become increasingly important over the years, not only for the individual but also for public health. In this paper, we intend to describe sport’s physiological and psychosocial health benefits, stemming both from physical activity and from sport participation per se. This narrative review summarizes research and presents health-related data from Swedish authorities. It is discussed that our daily lives are becoming less physically active, while organized exercise and training increases. Average energy intake is increasing, creating an energy surplus, and thus, we are seeing an increasing number of people who are overweight, which is a strong contributor to health problems. Physical activity and exercise have significant positive effects in preventing or alleviating mental illness, including depressive symptoms and anxiety- or stress-related disease. In conclusion, sports can be evolving, if personal capacities, social situation, and biological and psychological maturation are taken into account. Evidence suggests a dose–response relationship such that being active, even to a modest level, is superior to being inactive or sedentary. Recommendations for healthy sports are summarized.

1. Introduction

Sport is a double-edged sword regarding effects on health. Positive effects are achieved primarily through physical activity, which is the main part of most sports. Many secondary effects of sport also bring health benefits, such as psychosocial development of both young [ 1 ] and old [ 2 ], personal development [ 3 ], later onset, and less consumption of alcohol [ 4 , 5 ]. Finally, those who play sports have a higher level of physical activity later in life [ 6 ], and through sport, knowledge of nutrition, exercise, and health can be developed [ 7 ]. Negative effects include the risk of failure leading to poor mental health [ 8 , 9 ], risk of injury [ 10 , 11 ], eating disorders [ 12 ], burnout [ 13 ], and exercise-induced gastrointestinal tract discomfort [ 14 ]. In sport, there are unfortunately also reports of physical and psychological abuse [ 15 ]. Negative aspects are more common in elite-level sports, where there is a fine balance between maximum performance and negative health. A somewhat unexpected effect of sport participation is that people submitting to planned training in some cases perform less physical activity compared to those who are exercising without a set schedule. One explanation can be a reduced spontaneous physical activity in the latter group [ 16 ]. Because physical activity is increasingly executed in an organized manner [ 17 , 18 , 19 ], sport’s role in society has become increasingly important over the years, not only for the individual but also for public health.

In this paper, we describe the health effects of sport from a physiological and psychological perspective, related both to physical activity and added values of sport per se. Initially, brief definitions of various concepts related to physical activity and health are given. This is then followed by: (1) A brief description of how physical activity and training affect our body from a physiological perspective; (2) a report on the health effects of physical activity and training; and (3) sport’s specific influences on the various dimensions of health. We chose to discuss the subject from an age-related perspective, separating children/adolescents, adults, and the elderly, as well as separating for sex in each age group.

2. Definitions of Physical Activity, Exercise, Training, Sport, and Health

Definitions and terms are based on “Physical activity in the prevention and treatment of disease” (FYSS, www.fyss.se [Swedish] [ 20 ]), World Health Organization (WHO) [ 21 ] and the US Department of Human Services [ 22 ]. The definition of physical activity in FYSS is: “Physical activity is defined purely physiologically, as all body movement that increases energy use beyond resting levels”. Health is defined according to the World Health Organization (WHO) as: “[…] a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity” [ 21 ].

Physical activity can occur spontaneously (leisure/work/transport) or organized and be divided according to purpose: Physical exercise is aimed primarily at improving health and physical capacity. Physical training is aimed primarily at increasing the individual’s maximum physical capacity and performance [ 23 ]. Physical inactivity is described as the absence of body movement, when energy consumption approximates resting levels. People who do not meet recommendations for physical activity are considered physically inactive and are sometimes called “sedentary”. Sport can be organized by age, sex, level of ambition, weight or other groupings [ 24 ]. Sport can also be spontaneous [ 7 , 17 ] and defined as a subset of exercises undertaken individually or as a part of a team, where participants have a defined goal [ 7 ]. General recommendations for physical activity are found in Table 1 , not considering everyday activities. One can meet the daily recommendations for physical activity by brief, high-intensity exercise, and remaining physically inactive for the rest of the day, thereby creating a “polarization” of physical activity: Having a high dose of conscious physical training, despite having a low energy expenditure in normal life due to high volumes of sedentary time. Polarization of physical activity may lead to increased risk of poor health despite meeting the recommendations for physical activity [ 25 , 26 , 27 ]. During most of our lives, energy expenditure is greater in normal daily life than in sport, physical training, and exercise, with the exceptions of children and the elderly, where planned physical activity is more important [ 28 ].

Recommendations regarding physical activity for different target groups. Note that additional health effects can be achieved if, in addition to these recommendations, the amount of physical activity increases, either by increasing the intensity or duration or a combination of both.

Compiled from FYSS 2017 ( www.fyss.se ) and WHO 2017 ( www.who.int ).

3. Aerobic and Muscle-Strengthening Physical Activity

Physical activity is categorized according to FYSS as: (1) Aerobic physical activity and (2) muscle-strengthening physical activity. Physical activity in everyday life and exercise training is mainly an aerobic activity, where a majority of energy production occurs via oxygen-dependent pathways. Aerobic physical activity is the type of activity typically associated with stamina, fitness, and the biggest health benefits [ 29 , 30 , 31 ]. Muscle-strengthening physical activity is referred to in everyday language as “strength training” or “resistance training” and is a form of physical exercise/training that is primarily intended to maintain or improve various forms of muscle strength and increase or maintain muscle mass [ 32 ]. Sometimes, another category is defined: Muscle-enhancing physical activity, important for maintenance or improvement of coordination and balance, especially in the elderly [ 33 ]. According to these definitions, muscle-strengthening activities primarily involve the body’s anaerobic (without oxygen) energy systems, proportionally more as intensity increases.

Exercise intensity can be expressed in absolute or relative terms. Absolute intensity means the physical work (for example; Watts [W], kg, or metabolic equivalent [MET]), while relative intensity is measured against the person’s maximum capacity or physiology (for example; percentage of maximum heart rate (%HR), rate of perceived exhaustion (RPE), W·kg −1 or relative oxygen uptake in L·min −1 ·kg −1 (VO 2 )). In terms of recommendations to the public, as in Table 1 , the intensity is often described in subjective terms (“makes you breathe harder” for moderate intensity, and “makes you puff and pant” for vigorous intensity) [ 27 ]. While objective criteria such as heart rate and accelerometry will capture the intensity of activity, they may not distinguish between different types of physical activity behaviors [ 34 ]. FYSS defines low intensity as 20%–39% of VO 2 max, <40 %HR, 1.5–2.9 METs; moderate intensity as 40%–59% of VO 2 max, 60–74 %HR, 3.0–5.9 METs, and vigorous intensity as 60%–89% of VO 2 max, 75–94 %HR, 6.0–8.9 METs. Absolute intensity, however, can vary greatly between individuals where a patient with heart disease may have a maximal capacity of <3 MET, and an elite athlete >20 MET [ 35 ].

4. How does the Body Adapt to Physical Activity and Training?

Adaption to physical activity and training is a complex physiological process, but may, in the context of this paper, be simplified by a fundamental basic principle:” The general adaptation syndrome (GAS)” [ 36 , 37 , 38 ]. This principle assumes that physical activity disturbs the body’s physiological balance, which the body then seeks to restore, all in a dose-related response relationship. The overload principle states that if exercise intensity is too low, overload is not reached to induce desired physiological adaptations, whereas an intensity too high will result in fatigue and possibly overtraining. Thus, for adaptation to occur, greater than normal stress must be induced, interspersed with sufficient recovery periods for restoration of physiological balance [ 39 ]. During and immediately after physical exercise/training, functions of affected tissues and systems are impaired, manifested as temporarily decreased performance. You feel tired. In order to gradually improve performance capacity, repeated cycles of adequate overload and recovery are required [ 40 ]. In practice, positive effects can be seen after a relatively short period of a few weeks, but more substantial improvements if the training is maintained for a longer period.

As a rule of thumb, it is assumed that all people can adapt to physical activity and exercise, but the degree of adaptation depends on many factors, including age, heredity, the environment, and diet [ 41 , 42 , 43 , 44 ]. The hereditary factor (genetics) may be the most critical for adaptation [ 45 ]. The degree of adaptation also depends on how the person in question trained previously; a well-trained athlete usually does not have the same relative improvement as an untrained one. Even if training is thought to be specific to mode, intensity, and duration, there are some overlaps. For example, it has been found that strength training in some individuals contributes to a relatively large positive impact on health and endurance, effects previously associated primarily with aerobic exercise [ 46 , 47 ]. The overload principle may, if applied too vigorously in relation to a person’s individual adaptation ability, have detrimental effects, including reduced performance, injury, overtraining, and disease [ 10 ]. Training is a commodity that must be renewed; otherwise, you gradually lose achieved performance improvements [ 48 ], although some capacities, such as muscle memory, seem to persist for life [ 49 ].

General recommendations for health may be stated, but individual predispositions make general training schedules for specific performance effects unpredictable. All exercise training should be adjusted to individual purposes, goals, and circumstances.

5. Health Effects of Physical Activity and Training

Human biology requires a certain amount of physical activity to maintain good health and wellbeing. Biological adaption to life with less physical activity would take many generations. People living today have, more or less, the same requirements for physical activity as 40,000 years ago [ 50 , 51 ]. For an average man with a body weight of 70 kg, this corresponds to about 19 km daily walking in addition to everyday physical activity [ 52 ]. For most people, daily physical activity decreases, while planned, conscious exercise and training increases [ 19 , 53 ]. Unfortunately, average daily energy intake is increasing more than daily energy output, creating an energy surplus. This is one reason for the increasing number of overweight people, and a strong contributor to many health problems [ 54 ]. More sedentary living (not reaching recommended level of physical activity), combined with increased energy intake, impairs both physical and mental capabilities and increases the risk of disease. Despite this, Swedes (as an example) seemed to be as physically active and stressed but had better general health in 2015, compared to 2004 ( Figure 1 ). Compared to 2004–2007, the Swedish population in 2012–2015 reported better overall health (more county-dots are blue) and less fatigue (smaller county-dots) with similar level of physical activity (~65% indicated at least 30 min daily physical activity) and stress (~13% were stressed).

Selected physical and mental health indicators of a Sweden cohort, in relation to the degree of physical activity for the period of years 2004–2007 ( N = 29,254) and years 2012–2015 ( N = 38,553). Surveyed subjects are age 16 to 84 years old, with data representing median scores of four years, not normalized for age. Y-axis: Percentage of subjects reporting “stressed”; X-axis: Percentage of subjects indicating physical active at least 30 minutes each day. Each dot represents one County (Län), dot-size indicates self-reported fatigue, and color self-reported healthiness of the County. If 70% of the population states they are having “Good/Very good” health, the dot is blue. If less than 70% states they are having good/very good health, the dot is red. The circle indicated with a black arrow corresponds to nation median. The black line connected to the nation circle represents the movement in the X–Y plane from the year 2004 to 2007, and from 2012 to 2015, respectively. Data retrieved from the Public Health Agency of Sweden 2019-04-22 ( www.folkhalsomyndigheten.se ).

Results in Figure 1 may in part be explained by a polarization of who is physically active: Some individuals are extremely active, others very inactive, giving a similar central tendency (mean/median). As physical activity and mental stress are not changed, but health is, the figure indicates that other factors must be more important to our overall health and fatigue. Recently, a national study of Swedish 11- to 15-year-olds concluded that this age group is inactive for most of their time awake, that is, sitting, standing or moving very little [ 55 ]. Time as inactive increased with age, from 67 percent for 11-year-olds to 75 percent for 15-year-olds. The study states that in all age groups, the inactive time is evenly distributed over the week, with school time, leisure time, and weekend. Further, those who feel school-related stress have more inactive time, both overall and during school hours, than those who have less school-related stress.

People active in sports have, in general, better health than those who do not participate in sports, because they are physically and mentally prepared for the challenges of sports, abilities that in many cases can be transferred to other parts of life [ 56 ].

However, there is a certain bias in this statement. Sport practitioners are already positively selected, because sickness and injury may prevent participation. As many health benefits of sport are related to the level of physical activity, separation of sport and physical exercise may be problematic. Regardless, societal benefits of these health effects can be seen in lower morbidity, healthier elderly, and lower medical costs [ 7 , 57 , 58 ].

Health effects of physical activity in many cases follow a dose–response relationship; dose of physical activity is in proportion to the effect on health [ 59 , 60 ]. Figure 2 depicts the relationship between risk of death and level of physical activity, in a Finnish twin cohort, adjusted for smoking, occupational group, and alcohol consumption [ 59 ]. Odds ratio (OR) for the risk of all-cause mortality in a larger sample in the same study was 0.80 for occasional exercisers ( p = 0.002, 95% CI = 0.69–0.91). This dose–response relationship between risk of all-cause mortality and physical activity is evident in several extensive studies [ 60 , 61 , 62 ]. The total dose is determined by the intensity (how strenuous), duration (duration), and frequency (how often). While Figure 2 shows sex differences in death rates, it is likely that sedentary behavior is equally hazardous for men and women, but inconsistent results sometime occur due to inadequate assessment measures, or low statistical power [ 59 , 63 ]. To obtain the best possible development due to physical exercise/training, both for prevention and treatment purposes, a basic understanding of how these variables affect the dose of activity is required, as well as understanding how they can be modified to suit individual requirements. A physically active population is important for the health of both the individual and society, with sport participation being one, increasingly important, motivator for exercise.

Relative risk (odds ratio; OR) of premature death in relationship to level of physical activity, in 286 male and 148 female twin pairs, adjusted for smoking, occupational group, and use of alcohol [ 59 ].

There is strong scientific evidence supporting an association between physical exercise/training and good physical and mental health. For example: A reduction in musculoskeletal disorders and reduced disability due to chronic disease [ 27 , 64 ], better mental health with reduced anxiety [ 65 , 66 ], insomnia [ 67 ], depression [ 31 ], stress [ 68 ], and other psychological disorders [ 69 ]. Physical and mental health problems are related to an increased risk of developing a number of our major public health diseases and may contribute to premature death ( Table 2 ).

Health-related physiological effects of aerobic and muscle strengthening physical activity. Green circle indicates that the activity contributes with an effect, whereas a red circle indicates that the activity has no proven effect. Orange circle indicates that the activity may in some cases be effective.

5.1. Effects on Physical Health

The effects of physical activity and exercise are both acute (during and immediately after) and long-lasting. Effects remaining after a long period of regular physical activity have far-reaching consequences for health and are described below. For example, some muscle enzymes’ activity can be quickly increased by physical exercise/training but just as quickly be lost when idle [ 118 ]. Other changes remain for months or years even if training ends—for instance, increased number and size of muscle fibers and blood vessels [ 49 , 119 , 120 ]. Good health, therefore, requires physical activity to be performed with both progression and continuity. Most of the conducted physical exercise/training is a combination of both aerobic and muscle strengthening exercise, and it can be difficult to distinguish between their health effects ( Table 2 ).

To describe ill-health, indicators of life expectancy, disease incidence (number), and prevalence (how often) are used [ 121 ]. In describing the relationship between physical activity and falling ill with certain diseases, the dose–response relationship, the effect size (the risk reduction that is shown in studies), and the recommended type and dose of physical activity are considered [ 122 ]. Table 3 shows the relative effects of regular physical activity ton the risk of various diseases (US Department of Human Services, 2009). The greatest health gains are for people who move from completely sedentary to moderately active lifestyles, with health effects seen before measurable improvements in physical performance. Previously, most scientific studies collected data only on aerobic physical activity. However, resistance exercise also shows promising health (mental and physical) and disease-prevention effects [ 123 , 124 , 125 , 126 , 127 ].

Disease prevention effects of regular physical activity.

Compiled from US Department of Health and Human Service, https://health.gov/paguidelines/report/ [ 62 , 146 ] 1 : Risk reduction refers to the relative risk in physically active samples in comparison to a non-active sample, i.e., a risk reduction of 20% means that the physically active sample has a relative risk of 0.8, compared to the non-active sample, which has 1.0. 2 : In general, general recommendations for PA that are described and referred to herein apply to most conditions. However, in some cases, more specific recommendations exist, more in depth described by the US Department of Health and Human Service, amongst others [ 62 ]. 3 : Evidence is dependent on cancer subtype; refer to US Department of Health and Human Service [ 62 ] for in-depth guidance. PA = Physical.

Aerobic physical activity has been shown to benefit weight maintenance after prior weight loss, reduce the risk of metabolic syndrome, normalize blood lipids, and help with cancer/cancer-related side effects ( Table 2 and Table 3 ), while effects on chronic pain are not as clear [ 29 ].

Muscle-strengthening physical activity has, in contrast to aerobic exercise, been shown to reduce muscle atrophy [ 128 ], risk of falling [ 75 ], and osteoporosis [ 74 ] in the elderly. Among the elderly, both men and women adapt positively to strength training [ 129 ]. Strength training also prevents obesity [ 130 ], enhances cognitive performance if done alongside aerobic exercise [ 131 ], counteracts the development of neurodegenerative diseases [ 132 , 133 , 134 ], reduces the risk of metabolic syndrome [ 135 ], counteracts cancer/cancer-related side effects [ 135 , 136 ], reduces pain and disability in joint diseases [ 137 ], and enhances bone density [ 137 , 138 ]. The risk of falling increases markedly with age and is partly a result of reduced muscle mass, and reduced coordination and balance [ 76 , 139 , 140 ]. A strong correlation between physical performance, reduced risk of falls, and enhanced quality of life is therefore, not surprisingly, found in older people [ 141 ]. Deterioration in muscle strength, but not muscle mass, increases the risk of premature death [ 142 ] but can be counteracted by exercise as a dose–response relationship describes the strength improvement in the elderly [ 122 , 143 ]. Recommendations state high-intensity strength training (6–8 repetitions at 80% of 1-repetition maximum) as most effective [ 144 ]. Muscle strengthening physical activity for better health is recommended as a complement to aerobic physical activity [ 29 ]. Amongst the elderly, vibration training can be an alternative to increase strength [ 145 ].

5.2. Effects on Mental Health

Mental illness is a global problem affecting millions of people worldwide [ 147 ]. Headache, stress, insomnia, fatigue, and anxiety are all measures of mental ill health. The term “ ill health ” constitutes a collection of several mental health problems and symptoms with various levels of seriousness. Studies have compared expected health benefits from regular physical activity for improvement of mental health with other treatments, for example, medication. Most recent studies show that physical activity and exercise used as a primary, or secondary, processing method have significant positive effects in preventing or alleviating depressive symptoms [ 31 , 148 , 149 , 150 , 151 ] and have an antidepressant effect in people with neurological diseases [ 152 ]. Training and exercise improve the quality of life and coping with stress and strengthen self-esteem and social skills [ 69 , 153 ]. Training and exercise also lessen anxiety in people who are diagnosed with an anxiety- or stress-related disease [ 68 ], improve vocabulary learning [ 154 ], memory [ 155 , 156 ], and creative thinking [ 157 ].

The same Swedish data as used in Figure 1 show that between the years 2004–2007 and 2012–2015 anxiety, worry, and insomnia decreased but were not obviously correlated to the slightly increased level of physical activity in the population during the same period. Thus, in a multifactorial context, the importance of physical exercise alone cannot be demonstrated in this dataset.

Some of the suggested physiological explanations for improved mental health with physical activity and exercise are greater perfusion and increased brain volume [ 107 , 158 ], increased volume of the hippocampus [ 106 ], and the anti-inflammatory effects of physical activity, reducing brain inflammation in neurological diseases [ 159 ]. Physical exercise may also mediate resilience to stress-induced depression via skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), enhancing kynurenine conversion to kynurenine acid, which in turn protects the brain and reduces the risk for stress-induced depression [ 153 ]. Further, increased release of growth factors, endorphins, and signaling molecules are other exercise-induced enhancers of mental health [ 69 ].

6. How Sport Affects Health

Sport’s main purposes are to promote physical activity and improve motor skills for health and performance and psychosocial development [ 56 ]. Participants also gain a chance to be part of a community, develop new social circles, and create social norms and attitudes. In healthy individuals, and patients with mental illness, sport participation has been shown to provide individuals with a sense of meaning, identity, and belonging [ 160 , 161 ]. Whether the sport movement exists or not, training and competition including physical activity will happen. Sport’s added values, in addition to the health benefits of physical activity, are therefore of interest. Some argue that it is doubtful, or at least not confirmed, that health development can come from sport, while others believe that healthy sport is something other than health, reviewed in depth by Coakley [ 162 ]. In a sporting context, health is defined as subjective (e.g., one feels good), biological (e.g., not being sick), functional (e.g., to perform), and social (e.g., to collaborate) [ 163 ]. Holt [ 56 ] argued that the environment for positive development in young people is distinctly different from an environment for performance, as the latter is based on being measured and assessed. That said, certain skills (goal setting, leadership, etc.) can be transferred from a sporting environment to other areas of life. The best way to transfer these abilities is, at the moment, unclear.

Having the goal to win at all costs can be detrimental to health. This is especially true for children and adolescents, as early engagement in elite sports increases the risk of injury, promotes one-dimensional functional development, leads to overtraining, creates distorted social norms, risks psychosocial disorders, and has the risk of physical and psychological abuse [ 15 , 164 ]. Of great importance, therefore, is sport’s goal of healthy performance development, starting at an early age. For older people, a strong motivating factor to conduct physical activity is sports club membership [ 165 ]. One can summarize these findings by stating sport’s utility at the transition between different stages of the life; from youth to adulthood and from adulthood to old age. There, sports can be a resource for good physical and mental health [ 166 ].

Today, a higher proportion of the population, compared to 50 years ago, is engaged in organized sports, and to a lesser extent performs spontaneous sports ( Figure 3 ), something that Engström showed in 2004 [ 17 ] and is confirmed by data from The Swedish Sports Confederation ( www.rf.se ). Of the surveyed individuals in 2001, 50%–60% of children and young people said they were active in a sports club. The trend has continued showing similar progression to 2011, with up to 70% of school students playing sports in a club. Furthermore, the study shows that those active in sport clubs also spontaneously do more sports [ 167 ]. Similar data from the years 2007–2018, compiled from open sources at The Swedish Sports Confederation, confirm the trend with an even higher share of youths participating in organized sports, compared to 1968 and 2001 ( Figure 4 ).

Spontaneous sport has decreased over the last decades, to the advantage of organized sport. Data compiled from Engström, 2004, The Swedish Research Council for Sport Science.

Data compiled from open sources report Sport Statistics (Idrotten i siffror) at The Swedish Sports Confederation for the year 2011 ( www.rf.se ).

Taking part in sports can be an important motivator for physical activity for older people [ 165 , 166 ]. With aging, both participation in sports ( Figure 4 ) and physical activity in everyday life [ 168 ] decreases. At the same time, the number of people who are physically active both in leisure and in organized sports increases (The Public Health Agency of Sweden 2017; www.folkhalsomyndigheten.se ). Consequently, among elderly people, a greater proportion of the physical activity occurs within the context of sport [ 8 , 28 ]. Together, research shows that organized sports, in clubs or companies, are more important for people’s overall physical activity than ever before. Groups that are usually less physically active can be motivated through sport—for example, elderly men in sport supporters’ clubs [ 169 ], people in rural areas [ 170 ], migrants [ 171 ], and people with alternative physical and mental functions [ 172 ]. No matter how you get your sporting interest, it is important to establish a physical foundation at an early age to live in good health when you get older ( Figure 5 ). As seen in Figure 5 , a greater sport habitus at age 15 results in higher physical activity at 53 years of age. Early training and exposure to various forms of sports are therefore of great importance. Participation creates an identity, setting the stage for a high degree of physical activity later in life [ 173 ].

Odds ratio (OR) of physical activity at age 53 in relation to Sport habitus at age 15. Sport habitus (“the total physical capital"), including cultural capital, athletic diversity, and grades in physical education and health are, according to Engström [ 173 ], the factors most important for being physically active in later life. For a further discussion on sport habitus, the readers are referred to Engström, 2008 [ 173 ]. Numbers above bar show the 95% confidence interval. ** = significant difference from “Very low”, p < 0.01. *** = p < 0.001.

7. Sport’s Effects on the Health of Children and Young People

The effects of participation in organized sports for children and young people are directly linked to physical activity, with long term secondary effects; an active lifestyle at a young age fosters a more active lifestyle as an adult. As many diseases that are positively affected by physical activity/exercise appear later in life, continued participation in sport as an adult will reduce morbidity and mortality.

It must be emphasized that good physical and mental health of children and young people participating in sport requires knowledge and organization based on everyone’s participation. Early specialization counteracts, in all regards, both health and performance development [ 174 , 175 ].

7.1. Positive Aspects

According to several reviews, there is a correlation between high daily physical activity in children and a low risk for obesity, improved development of motor and cognitive skills, as well as a stronger skeleton [ 176 , 177 ]. Positive effects on lipidemia, blood pressure, oxygen consumption, body composition, metabolic syndrome, bone density and depression, increased muscle strength, and reduced damage to the skeleton and muscles are also described [ 178 , 179 ]. If many aspects are merged in a multidimensional analysis [ 8 , 173 ], the factors important for future good health are shown to be training in sports, broad exposure to different sports, high school grades, cultural capital, and that one takes part in sport throughout childhood ( Table 4 ).

Compiled health profiles for men and women at the age of 20 years, depending on participation in organized sports at the age of 5, 7, 8, 10, 14, and 17 years.

Classification with repeated latent class analysis creates three groups for girls and boys, respectively: Children who never participated (girls only), participated, quit prematurely, or began late (only boys) in sports. Arrows indicate whether participation in sports at young age has an effect on health at 20 years of age. Green up arrow is positive, red down arrow negative, and a horizontal black double arrow shows that sport had no significant effect. Modified from Howie et. al., 2016 [ 8 ].

Psychological benefits of sports participation of young people were compiled by Eime et al. [ 1 ], where the conclusion was that sporting children have better self-esteem, less depression, and better overall psychosocial health. One problem with most of these studies, though, is that they are cross-sectional studies, which means that no cause–effect relationship can be determined. As there is a bias for participating children towards coming from socially secure environments, the results may be somewhat skewed.

7.2. Negative Aspects

As Table 4 and Table 5 show, there are both positive and negative aspects of sports. Within children’s and youth sports, early specialization to a specific sport is a common phenomenon [ 175 ]. There is no scientific evidence that early specialization would have positive impact, neither for health nor for performance later in life [ 175 ]. No model or method including performance at a young age can predict elite performance as an adult. By contrast, specialization and competitiveness can lead to injury, overtraining, increased psychological stress, and reduced training motivation, just to mention a few amongst many negative aspects [ 174 , 175 ]. Another important aspect is that those who are excluded from sports feel mentally worse [ 8 ]. As there is a relationship between depressive episodes in adolescence, and depression as adults [ 116 ], early exclusion has far-reaching consequences. Therefore, sports for children and young people have future health benefits by reducing the risk of developing depression and depressive symptoms, as well as improved wellbeing throughout life.

Positive and negative aspects with sport (at young age).

While some degree of sport specialization is necessary to develop elite-level athletes, research shows clear adverse health effects of early specialization and talent selection [ 180 ]. More children born during the fall and winter (September–December) are excluded [ 181 ], and as a group, they are less physically active than spring (January–April) children, both in sports and leisure ( Figure 6 ). In most sports and in most countries, there is a skewed distribution of participants when sorted by birth-date, and there are more spring children than fall children among those who are involved in sport [ 182 , 183 , 184 , 185 , 186 ]. Because a large part of the physical activity takes place in an organized form, this leads to lower levels of physical activity for late-born persons (Malm, Jakobsson, and Julin, unpublished data). Early orientation and training in physical activity and exercise will determine how active you are later in life. Greater attention must be given to stimulating as many children and young people as possible to participate in sport as long as possible, both in school and on their leisure time. According to statistics from the Swedish Sports Confederation in 2016, this relative-age effect persists throughout life, despite more starting than ending with sport each year [ 18 ].

The figure shows the distribution of 7597 children aged 10 years and younger who in 2014 were registered as active in one particular, individual sport in Sweden (data compiled from the Swedish Sport Confederation, www.rf.se ). Spring, Summer, and Fall represent January–April, May–August, and September–December, respectively.

When summarize, the positive and negative aspects of sport at a young age can be divided into three categories: (1) Personal identification, (2) social competence, and (3) physiological capacity, briefly summarized in Table 5 . A comprehensive analysis of what is now popularly known as “physical literacy” has recently been published [ 187 ].

7.3. Relevance of Sports

Sports can make children and young people develop both physically and mentally and contribute with health benefits if planned and executed exercise/training considers the person’s own capacities, social situation, and biological as well as psychological maturation. In children and adolescents, it is especially important to prevent sports-related injuries and health problems, as a number of these problems are likely to remain long into adulthood, sometimes for life. Comprehensive training is recommended, which does not necessarily mean that you have to participate in various sports. What is required is diverse training within every sport and club. Research shows that participation in various sports simultaneously during childhood and adolescence is most favorable for healthy and lifelong participation [ 8 , 173 , 188 , 189 ].

8. Sport’s Effects on the Health of Adults and the Elderly

Adults who stop participating in sports reduce their physical activity and have health risks equal to people who have neither done sports nor been physical [ 190 , 191 ]. Lack of adherence to exercise programs is a significant hindrance in achieving health goals and general physical activity recommendations in adults and the elderly [ 192 ]. While several socioeconomic factors are related to exercise adherence, it is imperative that trainers and health care providers are informed about factors that can be modulated, such as intervention intensity (not to high), duration (not too long), and supervision, important for higher adherence, addressed more in depth by Rivera-Torres, Fahey and Rivera [ 192 ].

Healthy aging is dependent on many factors, such as the absence of disease, good physical and mental health, and social commitment (especially through team sports or group activities) [ 193 ]. Increased morbidity with age may be partly linked to decreased physical activity. Thus, remaining or becoming active later in life is strongly associated with healthy aging [ 194 ]. With increased age, there is less involvement in training and competition ( Figure 4 ), and only 20% of adults in Sweden are active, at least to some extent, in sports clubs, and the largest proportion of adults who exercise do it on their own. The following sections describes effects beyond what is already provided for children and youths.

8.1. Positive Aspects

Participation in sports, with or without competition, promotes healthy behavior and a better quality of life [ 166 ]. Exclusion from sports at a young age appears to have long-term consequences, as the previously described relative age effect ( Figure 6 ) remains even for master athletes (Malm, Jakobsson, and Julin, unpublished data). Because master athletes show better health than their peers [ 95 ], actions should be taken to include adults and elderly individuals who earlier in life were excluded from, or never started with sport [ 195 ]. As we age, physical activity at a health-enhancing intensity is not enough to maintain all functions. Higher intensity is required, best comprising competition-oriented training [ 196 , 197 ]. One should not assume that high-intensity exercise cannot be initiated by the elderly [ 198 ]. Competitive sports, or training like a competitive athlete as an adult, can be one important factor to counter the loss of physical ability with aging [ 199 ]. In this context, golf can be one example of a safe form of exercise with high adherence for older adults and the elderly, resulting in increased aerobic performance, metabolic function, and trunk strength [ 200 , 201 ].

8.2. Negative Aspects

Increased morbidity (e.g., cardiovascular disease) with aging is seen also among older athletes [ 202 ] and is associated with the same risk factors as in the general population [ 203 ]. An increased risk of cardiovascular disease among adults (master) compared to other populations has been found [ 204 ]. Unfortunately, the designs and interpretations of these studies have been criticized, and the incidence of cardiac arrest in older athletes is unclear [ 205 ]. In this context, the difference between competitive sports aiming to optimize performance and recreational sports has to be taken into account, where the former is more likely to induce negative effects due to high training loads and/or impacts during training and games. Although high-intensity training even for older athletes is positive for aerobic performance, it does not prevent the loss of motor units [ 206 ].

Quality of life is higher in sporting adults compared to those who do not play sports, but so is the risk of injury. When hit by injury, adults and young alike may suffer from psychological disorders such as depression [ 207 ], but with a longer recovery time in older individuals [ 208 ]. As with young athletes, secession of training at age 50 years and above reduces blood flow in the brain, including the hippocampus, possibly related to long-term decline in mental capacity [ 209 ].

8.3. Relevance of Sport

As for children and young people, many positive health aspects come through sport also for adults and the elderly [ 210 ]. Sport builds bridges between generations, a potential but not elucidated drive for adults’ motivation for physical activity. The percentage of adults participating in competitive sports has increased in Sweden since 2010, from about 20 percent to 30 percent of all of those who are physically active [ 18 ], a trend that most likely provides better health for the group in the 30–40 age group and generations to come.

9. Recommendations for Healthy Sport

• 1. Plan exercise, rest, and social life. For health-promoting and healthy-aging physical activity, refer to general guidelines summarized in this paper: Aerobic exercise three times a week, muscle-strengthening exercise 2–3 times a week.
• 2. Set long-term goals.
• 3. Adopt a holistic performance development including physiological, medical, mental, and psychosocial aspects.
• ○ a. Exercise load (time, intensity, volume);
• ○ b. Recovery (sleep, resting heart rate, appetite, estimated fatigue, etc.);
• ○ c. Sickness (when–where–how, type of infections, how long one is ill, etc.);
• ○ d. Repeat type- and age-specific physical tests with relevant evaluation and feedback;
• ○ e. Frequency of injuries and causes.
• ○ a. Motivation for training, competition, and socializing;
• ○ b. Personal perception of stress, anxiety, depression, alienation, and self-belief;
• ○ c. Repeat type- and age-specific psychological tests with relevant evaluation and feedback.
• 6. Register and interpret signs of overtraining, such as reduced performance over time, while maintaining or increasing exercise load.

Author Contributions

C.M. and A.J. conceived and designed the review. C.M., A.J., J.J. and interpreted the data and drafted the manuscript. J.J. edited the manuscript, tables, and figures. All authors approved the final version.

This work was supported by the Swedish Sports Confederation.

Conflicts of Interest

The authors declare no conflict of interest.

Latest Articles

Decision-making on injury prevention and rehabilitation in professional football – a coach, medical staff, and player perspective.

George Minoso 2024-04-08T09:47:11-05:00 April 8th, 2024 | General , Research , Sports Management |

Authors: Mads Røgen Noesgaard 1 & Stig Arve Sæther 2

1 Department of Sociology and Political Science, Norwegian University of Science and Technology, Trondheim, Norway 2 Department of Sociology and Political Science, Norwegian University of Science and Technology, Trondheim, Norway

Corresponding Author:

Stig Arve Sæther Department of Sociology and Political Science Norwegian University of Science and Technology, NTNU, Dragvoll, 7491 Trondheim, Norway E-mail: [email protected], https://orcid.org/0000-0002-1429-4746

Mads Røgen Noesgaard is educated as a physiotherapist and holds a master’s degree in sport science from the Norwegian University of Science and Technology. He has an extent experience as a physiotherapist from professional sports especially related to football and handball.

Stig Arve Sæther is an associate professor in sport science at the Norwegian University of Science and Technology, with an extensive research portfolio in talent development within sports and especially football. Sæther is head of the sport science staff, head of education at the department of Sociology and Political science and head of the research group Skill and Performance Development in Sports and School (SPDSS).

Purpose The aim of this study is to research how the decision-making on RTP from the medical staff impact on the perceived short- and long-term performance of the player and the team, from a coach, medical staff, and player perspective. Methods: Two professional football players, one physical coach, one physiotherapist and one assistant coach were interviewed in-depth and recruited because of their insight, experience, and expertise from one Norwegian premiere league club. Results: The decision-making process on RTP in the club were partly based on the hierarchy in the club, where the coach was on the top among these actors. Despite that the actor´s describes the process as a natural dynamic, and felt a shared responsibility in the process, their different roles impact on the decisions. The RTP decision was affected by aspects such as the period in the season, earlier injury experience of the player and the medical staff and coach collaboration. Conclusions: Even though the medical staff and the injury prevention could mean that the player could have a longer career, the choices made in the process of RTP is often based on short term player and team performance. Applications in sport: Professional football players have competition as a living and are expected to enjoy and embrace competing against both other teams related to winning trophies and teammates related to a place on the team in matches. This degree of competition was also seen as a part of the RTP process since the competition with teammates gave the players motivation to overcome their injury situation and get back to compete for their “spot” on the team. Even though this study only includes experiences from one professional football club, it gives insight into how the RTP process is done in a professional football context. Future studies should consider recruiting representatives from the club management, which also could give insight on how the macro aspects of a club impact on the RTP decisions in the coaching team of a professional football club.

Keywords : return-to-play, professional sports, communication

INTRODUCTION

The development of professional football player is complex and consist of a myriad of factors, including injury prevention and rehabilitation through the return to play (RTP) (38). Even though the development of injuries in European professional football has decreased over the last two decades (10), the impact of injuries still plays a major role in both team and individual player development and success (7). Time loss in on field training and matches may have a negative impact on the players development, which makes it vital to minimize the duration of rehabilitation and RTP process. The responsibility of injury prevention, treatment and following RTP has in the literature been described as the responsibility of the medical staff, even though a strong coach and player involvement has been recommended (10). Even so, lack of needed authority in this process, have been highlighted as a challenge since both the coaching team and especially the head coach, and the players are expected to be a part of the decision process, hereby creating a dilemma (26). The need for a high performing medical team is thereby indicated crucial for the present success, but also future accomplishments (7).

Knowing that the major predictor in future injury being previous injury (13, 27-28, 35, 45), it has become standard procedure in European professional football clubs to screen and evaluate both in-squad players and potential investments even though research points to a lack of predictive capabilities (29, 46). Hereby the screening process is arguably/potentially increasing the consequences of previous injuries and treatment of such and the importance of injury preventive measures. In the pursuit of securing the best possible squad at all times injury preventive programmes such as FIFA11+, seems common but often adjusted based on either screening results or coaches’ preferences and hereby losing its evidence-based merits (29-30, 34, 46). Another promising preventive strategy is tracking and managing of load and restitution of the individual player and indicated to both increase the “here and now” short-term performance and the long-term performance. The main aim is to reduce the risk of injuries and illness (19, 24, 36), but it also presents a risk of withdrawing players from training and matches unnecessary.

The rehabilitation process of a player must address and manage the psychological and sociological health of the player (12). Though the general plan and goals of the rehabilitation is clear there is a lack of gold-standard and consensus for RTP which complicates the last steps before returning to training and competition (22). The literature advocates a shared-decision-making process to optimize this process. Coaches, medical staff, physical coaches, and the individual player all possess insight about the state of the player seen in a bio-psycho-social framework (5-6, 8, 47). A process as such is nonetheless challenged by the different profession’s confidence in their own decision, but also potentially with a lack of trust in others, hereby creating a dilemma where authority and power becomes more important than teamwork (9-10, 20). To increase the overall medical effort, the literature advocates an SDM-approach to minimize injuries and rehabilitation periods and improve RTP (1). Still, Paul et al. newly published editorial are highlighting that there has been identified concerns surrounding the social complexities of elite sports and the difficulties of truly applying this concept in practice (37).

Most of the research on this subject and in professional football have used a quantitative approach (7) and there seems to be a need of qualitative insight on how this process unfolds in practice, and how and by whom the decisions are made. An exception is Law and Bloyce (25) who interviewed professional football managers behavior towards injured players. The results indicated that managers at the lower levels felt more constrained to take certain risks related to injured players. The aim of this study is to research how the decision-making on RTP from the medical staff impact on the perceived short- and long-term performance of the player and the team, from a coach, medical staff, and player perspective.

Participants 

Two professional football players, one physical coach, one physiotherapist and one assistant coach were interviewed in-depth and chosen based on strategic selection because of their insight, experience, and expertise in the field and their long-term involvement within one Norwegian premiere league club. The two players have in total more than 15 years in the club, while the physiotherapist and the physical coach has been in the club’s medical team for more than five years and altogether more than 20 years of experience in the field. The assistant coach has more than seven years of coaching experience. The participants are described in table 1.

All interviews were conducted in person and the location chosen by the interviewee. The length of each interview varied from 50 to 90 minutes with a mean at 70 minutes. Each interview was initiated with general questions to start the conversation and to get more background information on each participant. Prior to the interviews the questions were largely prepared to facilitate the conversation into different themes and topics of interest, with prepared follow up questions when depth and more context was needed. The questions varied specificity from general questions about the interviewee’s thoughts on the injury-period (e.g. “How do you think a player can develop while injured”) to more defined questions about the different actors’ actual role in the decision-making process about RTP (e.g. What role does the player has in the RTP-decisions). With these types of specific questions, the former mentioned extensive experience and expertise in the field was highly prioritized in the selection of participants. This made the insight in the specific club more extensive and gave the answers more depth. In addition, all participants were giving the opportunity to read through the transcript and afterwards able to withdraw parts or the interview in full, which none of the participants did. None of the participants neither wanted to alter the transcription. All interviews were audio-recorded and transcribed verbatim. By using pseudonyms for each participant, the transcriptions ensured the interviewee’ confidentiality and furthermore, ethical approval was in accordance with and approved by the Norwegian Social Sciences Data Services (number: 678375).          

Analysis The analysis of data was done with the six steps of theme-centred approach as described by Braun and Clarke (2-3). The process was initiated by the transcription by the first author who afterwards read and reread the data twice. This was followed by initial coding, phase two of the chosen method. In this process the transcription was revisited multiple times until the final codes were discovered and presented to the second writer for discussion. The total of 47 codes were structed using a mind-map, which visualised the third phase of the process and used to structure the data into nine higher-order themes. Phase four was a back-and-forth process rereading the transcript, revising the raw material for clarifying questions, reviewing the codes all in all to elaborate the emerged themes. Through dialog and discussion within the research group the final three/four themes were identified, and subgroups reviewed and hereby phase five concluded. Finally, phase 6 was a detailed process and highly interwoven with the analysis of data. To present the findings in an argumentation related to research question and to illustrate the story of the data it was important to revise the extracts and go back to the both the higher order themes and the final themes in the writing of the report to ensure that the essence of the data was captured and presented. The final report presents the experienced everyday life of the participants in this specific Norwegian Premier League football club, how they perceive the decision-making process in the context of both development and performance and how the structure and reality of modern football plays and important role in both injury prevention and RTP after injury.

The actors in the RTP process – the club hierarchy According to the actors (medical staff, coach and players), the prevention of injury and RTP practice has changed throughout the last decades, from a collective focus to a more specific and individual practice, described as a positive change by all the actors. RTP was described as a process, with benchmarks which was considered a motivational factor in the overall rehabilitation process. The decision-making process in the professional football club related to decisions on injured players and their capacity to play were affected to some degree by a hierarchy in the club. Even though the actor´s in the present study describes the process as a natural dynamic, and that they agree on their shared responsibility of the process, the different roles impact on the decisions.

Highest in the hierarchy are the coaches, and even though they highlight that the medical staff has an impact on their decision, the coaches seem to be the final decision maker in the process. This is indicated as a natural order because the coach is the one to take the ”fall” when the decisions shows to be wrong or more precisely have a negative output and also the final responsibility for the team performance. The coach described therefor a need to keep the medical staff on their toes, which the medical staff described as a challenge of their decisions, often based on what they considered external pressure on performance and results. This again meant that the medical staff had to make the “right” decision to keep their authority in the collaboration with the coaches.

The players felt in this regard that the medical staff had a two-sided role or responsibility both towards the coaches and the players, but that they still according to the players weigh the perspective of the player the heaviest. This double role was considered challenging and could mean lack of support in cases of doubt, while the medical staff considered that the final decision was taken by the coaches and the player. From the player perspective the trust was described as essential in this process. So even though trust, communication and collaboration are fundamental elements to keep a squad of players performing, there is also a need for a trust in the actors’ competencies and loyalty, both highlighted by the coach Lars: “Despite thinking about the result, first and foremost, we of course think: “The best for the player”. Because the player performs best when he is 100% healthy, both physically and mentally.” The physical coach Thomas stated this on the matter:

Thomas: “Because the vast majority of players understand deep down what the point is. They know when they shouldn’t go out there. They want to have hope, that: “yeah, it’s allright” and so sometimes our job is actually just to say: “Yes, it’s actually allright”, even if it’s 50/50, if it’s the last match on the season and they wanna take the chance anyways. Okay, then we have to see that and then just say: “This is allright”.

Thomas argued that their role in the process was to inform the coaches and even though the decision was not always in line with their suggestions, they felt that their opinions was considered vital for the final decision-making.

The factors that impact the decision process

Because of the complexity and uncertainty of who decides which players could play, the medical staff experience situations where at times they felt pressured to clear a player for playing, which in their experience often leads to a longer injury period. And despite the open communication, the pressure got more intense especially before important matches and at the end of the season, as this conversation and the following quotes indicates: Physiotherapist Hans: “You get a player who runs at 60%?”, Coach Lars: “Yes, but he is so important for us in set-pieces, so we have to have him”. This becomes even more prominent at the end of the season as physical coach Thomas highlights: “The fewer matches left, the greater chances you are willing to take with the athlete’s health”.

The decision to deny a player to train or play a match based on the risk of injury, was considered difficult for the medical staff because of uncertainty of the outcome. The coach describes how they in some cases start the player and see how it goes. Even though this was described as happening seldom and especially since this could be considered treating the players differently, which potentially could impact the team dynamic:

Lars: “If you and I play in the same position, and you train 3 times a week but you are a little better than me. I’m training every single day, and then you get to play matches. I train more than you, twice a week, and then arrangements will be made for you to play. That could become a conflict.”

The medical staff points out how this load-management strategy is potentially positive for RTP, the coach argument furthermore how this might add pressure for the next matches both for the player and the medical staff. If the team loses, one could consider that being in minus and that means that the next match must be won. This adds on to the earlier statement that an injury might be a heavy process for a player:

David: “From the moment you feel that you are a part of something, then you will show up the day after you have been injured, then you show up for work. You eat breakfast, you go to the locker room and then the rest of the team go out on field and do what you love the most, they play football. But you wander into a dark gym alone and do what all footballers think is the most boring job, cycling and doing rehab training. As boring as it gets. But you have to do it. You go into such a lonely and confined, empty mental phase, it’s really hard.”

What was considered the “right” decision depended on the perspective, even though obviously the most impacted part is the player:

Niels: “Perhaps I have been lucky in that I have not had so many major injuries, but at the same time the one injury I have had, where it was done the way it was done, that was enough for me to think: “yes, I lost some good matches that year”, then you can think of those who have been injured longer and have had more injuries, how much it has affected them.”

Injuries are however also described by all actors as a natural part of professional football, and that this often means taking risks to be able to perform on the highest level. One of the players, David, describes it as following:

David: “At the top level, you are balancing on a knife’s edge much more often, because you are pushing boundaries all the time and then the need for medical help is all the greater than when you operate at a not so fully professional level.”

It could seem from a professional players perspective that the players consider their everyday life as a footballer as finding the optimal balance to be able to stay fit and avoid injuries, and that this situation is difficult and that they need help from the medical staff to be able to keep staying “in the game”. Even so, the physical coach Lars highlights the difference between pain and injury:

Lars: “I think when you play football and it’s one-on-one, it’s dueling, you can get a knee in the side, you can get hit by an elbow, so after a football match, you might have a bruise here and a little bit of swelling there and you can have, stiffness in generel. That doesn’t mean you need 2-3 days to recover because that pain you feel”.

Protecting the players

The coach stated that it was important to protect the players and not introduce them for unnecessary risk, even though he pointed out that there is a limit in terms of how much consideration one could do for each player. In this regard did the physical coach acknowledges that there had not been a reduction in the number of injuries despite the heavy number of added resources to prevent them. The injuries have changed but one has not been able to eliminate the incident rate:

Thomas: “There is much less ankel rolls, but there are more hamstring injuries and groin injuries because there is more sprinting in the matches and the matches are closer schedueled. And you can’t quite solve that. Even with sufficient sleep, enough nutrition, tablets in the fusion of plasma, i.e. “you name it”, game ready – the player still breaks down and then you see that if you train very well, then maybe you will go through the season with very little damage.”

This was also something the players describes as problematic in certain situations, as stated by Niels: “Coach, physio and they, they really push you back in and then it’s difficult as a player to sit there and say: “I’m not healthy”, it’s difficult!”

The physical coach recons it is all about the time spent on the pitch to improve RTP and the high amount of matches impact on the possibilities for the medical staff to schedule and complete the injury preventions and rehabilitation. One example mentioned are an away match where the travel time is the reason for the player not attending enough training sessions, even though he is ready to train.  Furthermore, the game importance is an important factor because of the impact on the results sportingly and economically and has been found to be the reason as to why players play partly injured, or at least adding on to the pressure on the medical staff and their decision on every player potentially injured.

          Also, one of the players described how he perceived that the players are at their best when the get to train and play matches as much as possible:

David: “All footballers perform at their best when they get the opportunity to play football every day. Play every match. That’s when you get into a rhythm, where you act on intuition in battle and in that moment. In order to do that, you have to have continuity in your training and to have that, you have to be good at taking care of your body, to manage and last through a tough week of training, to perform in every match. So it’s definitely important. You profit from doing a good job (ed. injury prevention) in order to be able to perform in the best possible way. It is absolutely indisputable.”

Both the players and the medical staff highlights that the injury prevention is important for the players to be able to train more.  The physical coach highlights that this injury prevention training has a direct impact on the player opportunity to run faster and develop more power.

One of the players mentions how each club and their culture try to maximise the development and that the club culture is impacting the performance. This was also mentioned by the coach who stated that building the club is one of the most important tasks for the club, which is considered difficult since both players and coaches comes and goes. Another challenge is the impact the head coaches have on how the club perceive injury and development. The physiotherapist describes how the many changes also impact on the medical staff and their way of working:

Hans: “I think that, the biggest challenge in all of this is the constant change in player material, the constant change, at least as it has been in X, that coaches change, and therefore you constantly have different routines. It is natural that a coach who comes in and is boss wants to have it his way, and then a new coach comes in who wants it his way. Then there will always be changes and that means that what you tested on last year will be tested in a different way this year.”

Both players and the physical coach add on to this position, even though they also see positive outputs when new people are trying to collaborate:

Thomas: “Things that work well can also be diluted by poor execution. I think we make it work. I think so. that’s how it is when you bring new things to the table. Basically, it should be a good thing and if you manage to get best out of it, then it will be beneficial.”

The injury situation as an opportunity for development

All the actors thought of the injury period as a period for potential development of performance level of the player. So even though the players considered it as a tough and challenging period, it also contains opportunities. The coach highlighted that this motivation and opportunity had to come from within, and that he medical staff and the coach’s role was to facilitate and further motivate. In that way the injury period can be effective and also an opportunity, which could be considered a win-win situation both for the player and the team. 

Still, at times the players felt pressured to play, and sometimes felt alone and “naked” in the discussion between them, the medical staff and the coaches. This was partly confirmed by the physiotherapist, who described football as being black or white at times, and that he felt the need to protect the player:

Hans: “A player who is out several times and often… It can very quickly become black and white in a football club, “This player is always injured. No, we’ll give up on him a little”, and then it’s challenging to say: “You mustn’t give up on him, even if he’s a bit injured now. There are several factors that cause him to be injured and we have to look at ourselves as well, all of us.” What we have often done is to look at the coach and say: “If we are going to get him out of this, we’ll have to make a change. What we are doing now is not good enough. So we have to take him out of training and have to do this instead of that. He can’t play every game and at the moment”.

However, at other times the medical staff also feel the need to push the players to return to ordinary training or playing matches. They feel the need to be careful since they might misstep. Some players might get pushed back to soon, while others need a push.

Lars: “Sometimes where you have to push a little, and we really do that for the sake of the player, not because we absolutely have to. We don’t take any chances with players, that is. But if we see that he has done what he is supposed to and at the same time it is a player who is a bit more careful with himself. Because that too, you have to know the group, you have to know the player, because there are some who can be too tough too early, and then there are some who are actually ready, but holding back. So you can say that sometimes we have to try and push them in a positive way too, I think. Without us doing anything wrong.”

One of the players Niels stated that for some of the players, they need to be more included in the decision-making-process. One example mentioned by one of the players was the importance to get into the pre-season together with the squad, to be able to compete about his playing position.

The medical staff clearly stated that they did not consider themselves having the definitive solution in every case. They also mentioned the fact that holding a player back from a match based on the fear of being injured might deprive the player from development and potentially economic gain (e.g. club transfer, bonuses etc.) or the team’s performance or the club’s economic gains. Many of the actors highlighted that if the player felt ready to play, and the coaches meant that he would have an impact on the game, the medical staff would take that into consideration. This position of taking a decision which is good for all the actors both in a short-term and long-term perspective was considered a difficult dilemma for the medical staff, since they feel an extra responsibility related to the players health.

Keeping the players on their toes but still together

The coach also highlighted that the competition between players could challenge the individuals in the club. Internal competition is essential and when a player is injured, that could create an opportunity for other players. This competition was also highlighted by the two players, however as a stressor for the injured player. The coach however stated that this type of competition must be present and that it makes the players push each other, and fight for a place on the team. This type of pressure, trying to withhold your place on the team, having the right attitudes, frequent changes in the coaching staff, and short-term results, was describes from all the actors as impacting the medical staff’s opportunity to impact the decision for players to play matches and their development. Both the coach and the medical staff highlighted that this might impact the decision, but never determined the RTP, while the players could consider this as a weighty stressor

The players point out a potential isolation of the injured players by dividing the players into two groups: those who are injured and those who are not, but this division is described differently based on the perspective. They also describe the rehabilitation as lonely, heavy, and boring, especially the acute phase, and experience that the injured players not to be a part of the community in the club, which the player Niels described in the following: “But I want to put it this way, you are down in hell and then you start the ascent from there, and then it becomes a bit like tunnel vision. You don’t see the light at the start, but you see it eventually”. The coach, however, does not describe this as an isolation or division of the team, but rather a natural part of the everyday life in a club, but highlight the importance of joint meals and meeting schedules. The medical staff have another nuance of this division, since an injury might be challenging and create a sense of exclusion, while this could also be good for the team, since the negativity which often comes with an injury does not get spread among the other team members. The physical coach highlights the same and furthermore that it should be attractive not to be injured.

All the actors describe the deprivation from matches in times of doubt about a player’s availability have both sportingly and economic negative impact on the player’s career:

David: “Football can be so simpel that if you, how should I put it , score a hat-trick in the right match against the right team, you can be like… And the salaries are so high, so if you end up in the right place then you, then you can in a way support the whole family for the rest of your life. So it’s quite clear that injuries affect the course of a career.”

Injuries means less time to train, and the actors agree that the time for the specific football training and matches are essential for a player’s individual development. Both the coach and the physiotherapist highlighted however the importance of making the most of the injury period, which could be considered as a window of opportunity to focus on individual skill development, which normally one does not have time for. The physical coach stated however that it might be difficult for a player to develop largely during the rehabilitation process. And this could be related to the somewhat black-white perspective the medical staff and the coach has on injuries. The physiotherapist meant that this approach might have a positive consequence for a player who have experienced an injury. They often work harder than before to be able to get back to football. At the same time Hans also pointed to the fact that the players could be “forgotten” by the coaches if they achieve a “bad” reputation: “But if you first get a reputation of being.. that the coach gets the feeling that he is not available, then it can often be difficult. A fight really. That is my experience”. The coach Lars partly confirmed this by stating that the coaches are aware of players who have a history of injuries, which often mean that they cannot play all matches during a season:

Lars: “In other words, injury follows injury. It’s a bit like that. So there are certain players that you know more or less that he is not going to play 100% of the games. Let’s say there is an exclusive player who often gets hamstring issues, then you know that during the season he will play 70% of the games. It may happen that we have players, who we know are like that.”

In a long-term perspective and focusing on the players career, the coach also highlighted that the players are screened and assessed by clubs if a club transfer is in motion, that a player with a large injury history would be considered as less interesting to recruit:

Lars: “[…] But the more players who don’t have an injury history.. So if you’re going to build a team then you have to get as few players as possible with an injury history, because often you see that those type of issues, especially if it’s the groin or hamstring or those types of injuries, they often come back.”

The coach described players’ injury history as essential when clubs assess which player they could recruit, and that injured players must convince the coaches to become relevant for a club transfer. These types of assessment are important for coaches in their process of building a squad both in a short-term and long-term perspective.

The aim of this study is to research how the decision-making on RTP from the medical staff impact on the perceived short- and long-term performance of the player and the team, from a coach, medical staff, and player perspective. The decision-making process on RTP in this professional football club were partly based on the hierarchy in the club (40). So, despite that the actor´s in the present study describes the process as a natural dynamic, and felt a shared responsibility in the process, their different roles impact on the decisions. The coaches were described highest in the hierarchy and related to them being responsible for the sportingly results and the performance of the team. The players were described as having a say in the decision of his availability, even though they often highlighted an experience of being pressured to play in certain situations (9). The medical staff was considered to have a two-sided role, since they were employed and a part of the coaching team and naturally felt a responsibility on behalf of the coaches and the club, they also felt the need to protect the players and their health as professional health workers (20). Their decisions would often mean that they had to “disappoint” the coaches or the player, by denying the player to play or the availability of a player in a match.

Responsibility was a term especially the medical staff used to describe how they felt about their role, but also when taking part in the final decision in the RTP process. This responsibility became important in the process of making “the right” call based on the information available while trying to account for the interests of all the actors. This might mean that they let a player play, with a “let´s see how it goes” approach, and that the outcome of the decision was described as “right” if the player played the whole game. A dilemma in the process was also related to the natural part of pain and injury as part of professional football described by all the actors in the process (31). So even if protecting the players was important, time spent on the pitch is the main goal for both the individual players and the team’s development and performance. Even so, earlier research (41) has indicated that elite sports have a pain culture where pain is a natural and expected part of elite sports, which could have a negative impact on the players development, if this means that the players do not communicate when feeling injured or unavailable for training and matches.

Professional football is all about results and performance (32). So, a characteristic off successful environments is their constant search of areas to develop further (14). This seemed to be the case in this club as well since a period of injury was considered an opportunity for the player to develop. The players are competing about a place in the starting line-up and need to pick up the glow to get back into the team. Still, there was also a mutual understanding that each RTP case might be different and had to be considered individually. So, in some cases both the medical staff and the coaches felt that some players needed a push to get back. This may in many cases also be in the best interest of the player since it could mean that they in example get identified by scouts, impacting their career by a club transfer. Furthermore, this pressure could mean that the players are willing to take a higher risk by playing while injured. The players in this study described being injured as lonely and feeling isolated from the team, as found in earlier studies (32), which could be perceived as an increased motivation to RTP potentially even before the mind or body are ready.

In accordance with the focus on results and performance in professional football are also the high degree of uncertainty in this professional context (15). This could be related to the small margins between success and failure. This is also related to the RTP process, since all actors in the process of RTP must make the best decision for both the individual and teams’ performance. Still, there is a lack of knowledge related to the potential outcome of the decision. This means that the actors must “take risks” to be able to maximize the opportunity to succeed. While it was not a part of the study, the obvious economically benefits of decreasing time loss in training and competition on both an individually (players, medical team, and coaching team) and club level (potential sale of players), also makes both the rehabilitation and preventive strategies important. The club perspective might conflict with the individual actors in the RTP process, with the example of the club winning the league, while a player got injured because of the overload and hereby potentially ending his career.

CONCLUSIONS

All the actors in this study highlight that football is a sport where you must expect to feel pain regularly and that injury is a part of being a professional football player. So even though the medical staff and the injury prevention could mean that the player could have a longer career, the choices made in the process of RTP is often based on short term player and team performance. Professional football players have competition as a living and are expected to enjoy and embrace competing against both other teams related to winning trophies and teammates related to a place on the team in matches. This degree of competition was also seen as a part of the RTP process since the competition with teammates gave the players motivation to overcome their injury situation and get back to compete for their “spot” on the team. Even though this study only includes experiences from one professional football club, it gives insight into howe the RTP process is done in a professional football context. Future studies should consider recruiting representatives from the club management, which also could give insight on how the macro aspects of a club impact on the RTP decisions in the coaching team of a professional football club.

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Comparing Public vs. Private High School Sports-Related Concussions from a Countywide Concussion Injury Surveillance System

George Minoso 2024-03-18T11:04:24-05:00 April 5th, 2024 | General , Research , Sport Training |

Authors: Gillian Hotz 1 , Jacob R. Griffin 2 , Hengyi Ke 3 , Raymond Crittenden IV 4 , Abraham Chileuitt 5

1 Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA 2 KiDZ Neuroscience Center, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA 3 Department of Public Health, Division of Biostatistics, University of Miami Miller School of Medicine, Miami, FL, USA 4 Department of Neurology, University of Miami Miller School of Medicine, Miami, FL

Gillian Hotz, Ph.D. 1095 NW 14th Ter Miami, FL 33136 [email protected] 305-243-2074

Gillian A. Hotz, PhD is a research professor at the University of Miami Miller School of Medicine and a nationally recognized behavioral neuroscientist and expert in pediatric and adult neurotrauma, concussion management, and neurorehabilitation. Dr. Hotz is the director of the KiDZ Neuroscience Center, WalkSafe, and BikeSafe programs.

Purpose Largely, research on adolescent sports-related concussion (SRC) has focused on public school athletes. SRCs of private school athletes have been studied less and may differ due to differences between school types.

Methods SRCs between Miami-Dade County high school athletes at trained public (n = 1088), trained private (n = 272), and untrained private (n = 79) were compared. Outcomes included days between date of injury (DOI) and clinic date, days between DOI and post-injury ImPACT retest, days withheld, return to play (RTP), ImPACT baseline and post-injury retest completion, and academic accommodation status.

Results Trained public and trained private groups had similar days between DOI and clinic date, days withheld, and percentage who RTP. Differences between the trained public and untrained private groups existed for RTP but not for days between DOI and clinic date or days withheld. Private group athletes were more likely to receive academic accommodations.

Conclusions Public and private high schools trained on the same SRC protocol did not have significantly different outcomes. The untrained private schools, however, had worse outcomes compared to the public group.

Application In Sports SRC outcomes in both public and private high schools may benefit from SRC education, training, an established protocol, and use of a management system.

Keywords : youth athletes, concussion recognition, concussion management, private schools, sports

Each year, an estimated 1.6 to 3.8 million sports-related concussions (SRCs) occur in the United States (1). While the nearly 8 million high school athletes participating in sports annually benefit from the improved social, psychological, and physical health gained from playing sports (2, 3), there is also an ongoing risk of injury due to consistent athlete-exposure (4). SRCs are understandably a concern for high school aged athletes due to the short-term and potentially lifelong behavioral, cognitive, emotional, physical, and psychological effects they can produce (1, 5). These consequences can be particularly worrisome as this population is already experiencing their own ongoing physical and cognitive development changes that can negatively be affected by an SRC (6). Understanding risk factors contributing to adolescent SRCs and what may lead to differences in outcomes is therefore imperative for identifying those most at risk and ensuring the proper management and treatment resources are in place.

Thus far, an overwhelming majority of research on SRCs has focused on or included samples of public high school athletes as opposed to private high school athletes. One example is the High School Sports-Related Injury Surveillance Study, Reporting Information Online (RIO) (7). The High School RIO is an internet-based data collection tool that captures athletic exposures and injury events through athletic trainers (ATs) that report data. It is often used as a source of SRC data for research (4). In the most recent report, nearly 80% of the participating high schools were public with the rest being private (7). Additionally, other studies on SRC incidence and trends have included only athletes from public high schools (8.) The lack of private high school inclusion in adolescent SRC research is an important consideration because known distinctions between public and private high schools possibly lead to differences in SRC incidence and outcomes (4). These include differences in school size, support services and resources, student racial/ethnic backgrounds, rigorous academic programs, and socioeconomics (9).

While there has been recent research that details private high school athlete SRC experiences and reporting behavior (4, 10), there is still a need for continued research into private high school SRC outcomes. Specifically, it would be important to examine how SRC outcomes differ between public and private high schools. Therefore, the purpose of this study was to compare SRC outcomes between public high schools who received specific concussion training and education to private high schools who received the same training and private high schools who did not receive training on the same SRC protocol. The goal of using these three distinct groups was to examine whether differences in SRC outcomes would be a result of differences in SRC education, training, and protocol.

Participants and Procedures

This study included Miami-Dade County (MDC) public and private high school athletes with an SRC that occurred in a practice or game between August 1 st , 2012, and July 31 st , 2022. All athletes were treated at the University of Miami Miller School of Medicine’s Concussion Clinic, UConcussion (UCC). Athletes that sustained an SRC outside of the study period were excluded as well as those with an SRC that did not occur during an MDC public or private high school practice or competition. If an athlete was treated at a provider other than the UCC, they were also excluded. 

 The UCC clinical team hosts an annual SRC training and educational workshop for MDC public high school ATs and athletic directors (ADs). In these workshops, ATs and ADs are trained on how to use the Six Steps to Play Safe protocol (11) and how to administer ImPACT (12) concussion tests. The UCC also makes available specialty concussion clinics where athletes with a suspected SRC can be referred to for management and treatment. The UCC similarly partners with and provides training and education to 8 private high schools within MDC. While athletes at other private high schools within MDC can still be referred to and receive treatment at the UCC, ATs and ADs at these high schools are not provided with the same educational workshops and training on the Six Steps to Play Safe protocol (11). In this study, there were 35 trained public, 8 trained private, and 29 untrained private high schools that were grouped as either “trained public,” “trained private,” or “untrained private,” respectively.              

The Six Steps to Play Safe (11) is a standardized protocol that can be used to manage an athlete’s SRC and safe return to play (RTP) and return to school during recovery (Figure 1). Included in this protocol are, in order, pre-season ImPACT (12) baseline testing, AT sideline testing, post-injury ImPACT testing, SRC clinic follow-up, gradual RTP and return to learn protocols, and SRC injury surveillance form completion.

Variables Reported variables were collected during UCC visits and from surveillance reporting by ATs. Athlete information in the study included demographics and the sport played when the injury occurred. SRC specific information was also reported and included date of injury (DOI), days between DOI and first clinic date, days between DOI and post-injury ImPACT retest, RTP status (yes/no), and days between DOI and RTP (days withheld). To eliminate the few extreme outliers, athletes were only included in days between DOI and first clinic date as well as days withheld mean calculations if the value for these variables was < 120 days. For similar reasons, only athletes with days between DOI and post-injury ImPACT retest < 30 days were included in the calculation. Whether an athlete received academic accommodations was included as a variable because previous research (13) suggests that private high school students experience particularly high levels of stress due to concerns about academic performance and school requests, which potentially impacts whether academic accommodations are prescribed. The percentage of athletes who experienced loss of consciousness (LOC) was also reported because LOC indicates a potentially more severe SRC and is associated with longer recovery than SRCs without LOC (14). Athlete ImPACT (12) baseline testing and post-injury data from the ImPACT test online database was included and used to determine whether athletes had completed a baseline ImPACT test and/or a post-injury ImPACT retest. ImPACT testing comparisons were only included for the trained public and trained private high schools since untrained private high schools either did not use ImPACT or did not grant the UCC access to their records.

Data Analysis Data analysis was performed using R 4.2.2. Athletes sustaining an SRC from MDC public high schools were compared with athletes from private schools between 2012-2022. The eight private schools were particularly selected because they followed a similar protocol and received the same SRC education as the public schools. The other 29 private schools did not receive the training or follow the protocol. For continuous data in the normal distribution like “Age”, mean and standard deviation were reported. For categorical data, such as “Gender”, data was presented as frequency and percentage. For those variables with important clinical significance, such as “Days withheld”, data was reported as median and interquartile range. Propensity score matching was performed to match the public schools with the eight private schools who received similar SRC training. SRC outcomes were therefore compared between trained public and trained private schools before and after matching. This was done to confirm whether one hypothesis, that public and private schools trained on the same SRC protocol would not differ in SRC outcomes, would be true when baseline covariates were and were not controlled for between the groups. Sample T-test was used to detect the significant difference for quantitative data in the normal distribution. The Wilcoxon test was used for quantitative data in non-normal distribution. The Chi-Square test was used to detect significant differences in categorical data. Statistical significance was set at < 0.05.

Participant Demographics A total of 1,088 public, 272 trained private, and 79 untrained private athletes were treated at the UCC during the study period and are included in this study. The average age was similar for each group (16.5 and 16.2). While there were more male than female athletes in all three groups, the percentage of athletes that were female was greater in the trained (38.6%) and untrained (38.0%) private groups than the public group (25.9%). In both the trained and untrained private groups, a greater percentage of athletes were White (28.5% and 25.3%) or Hispanic (62.6% and 68.0%) compared to public athletes (8.0% White, 56.4% Hispanic). The public group instead had a greater percentage of Black athletes (30.9%) than the trained (24.7%) and untrained (6.7%) private groups. Across all three groups, football accounted for the greatest percentage of SRCs but was more prevalent in the public (58.3%) than both private groups (36.4% and 39.2%) (Table 1).

Comparing Trained Public and Trained Private High Schools SRCs Data from trained public and trained private high schools was compared to determine if there were any differences in outcomes between public and private high schools that were trained using the same protocol and program. There were no differences between the groups for days between DOI and first clinic date (P = 0.1), days withheld (P = 0.83), post-injury retest completion (P = 0.06), and RTP (P = 0.30). The average days between DOI and post-injury ImPACT retesting was smaller (P < 0.001) for the public (3 days) than trained private (6 days) group. The public group also had a greater percentage of athletes who completed ImPACT baseline testing (88.5% vs. 80.1%; P < 0.001). The trained private group had a significantly greater percentage of athletes who had academic accommodations (P < 0.001) and experienced LOC (P < 0.001) (Table 2).

After matching, groups had similar demographic characteristics for age, sex, race, grade, and sport (Table 3). Outcomes between the matched groups were also compared, and there were no differences for days between DOI and first clinic date, days withheld, percentage of athletes who completed ImPACT baseline testing and post-injury retesting, and RTP (Table 4). However, average days between DOI and post-injury ImPACT retest was smaller for the public group (4 vs. 6 days, P < 0.001). The public-school group was also more likely to have experienced LOC (P < 0.001) and not receive academic accommodations (P < 0.001).

Comparing Trained Public and Untrained Private High School SRCs Trained public and untrained private groups did not differ in average days between DOI and first clinic date (P = 0.40) or days withheld (P = 0.40). A significantly greater percentage of the public group did RTP (91.9% vs. 81.0%; P = 0.002). More of the athletes in the untrained private group received academic accommodations (P < 0.001) and experienced LOC (P < 0.001) than did the trained public group (Table 5).

Understanding risk factors, whether demographical (e.g., sex, age) or injury event-related (e.g., sport, mechanism of injury), that are associated with differences in SRC outcomes are important for ensuring that those most at risk receive proper SRC treatment and resources. One potential risk factor that was explored in this study was whether an athlete was from a public or private high school. Historically, most research on SRC risk and outcomes has been conducted using public high school athletes (4). This study provides further insight into how SRC outcomes between high school athletes differ based on the type of school attended and if a dedicated SRC protocol and education can help mitigate any differences.

While football accounted for the greatest percentage of SRCs in all three groups, its contribution was roughly 20% percent more in the public group than both private groups. Other sports, including soccer, basketball, and volleyball, were more prevalent in both private school groups. The distribution of sport played during the SRC injury event likely differed between public and private groups because private schools offer a variety of sport options, like crew and sailing, that were not available at public schools. This availability may have impacted the popularity of sports and participation numbers as private school athletes had a greater number of sports to choose from.

To our knowledge, there is only one other study (15) that directly compares SRC experiences between public and private schools. In that study, private school athletes were twice as likely to report a history of SRC compared to public school athletes, but there was no difference in RTP timelines between athletes at the different types of school (15). While the current study did not compare history of SRC between school types, analysis was performed to compare rates of RTP. There was no significant difference between the trained public and trained private school groups for RTP percentage or days withheld (Table 2), similar to the other study that concluded no difference in RTP. After matching, there was still no difference in RTP percentage or days withheld between these groups (Table 4). The untrained private group, however, had significantly less athletes RTP than the trained public group (Table 5). The UCC is a specialized concussion program that provides comprehensive SRC management and treatment, but the program also provides continuing education and a standardized protocol to the trained public and private high schools to better identify, manage, and treat athletes with an SRC (11). Athletes at these participating trained high schools potentially benefited from the coordinated and structured care they receive as a result of these trainings and partnerships, which may have led to better RTP outcomes compared to the untrained private group. These results also suggest that SRC outcomes do not necessarily depend on school type and the systematic differences between public and private schools (4, 9), but instead on AT and AD SRC education and if an SRC protocol is in place and being followed. Additionally, these results also indicate the positive effect an available and established SRC program and protocol with clinicians trained on SRC management and treatment can have on SRC outcomes. Another finding was that the trained public and untrained private groups did not differ in average days between DOI and first clinic date (Table 5). Systematic differences in socioeconomics between public and private high schools (9) may explain why the trained public group did not have significantly fewer average days between DOI and first clinic date than the untrained private group, which was the initial hypothesized result. There is well established evidence (16) that supports a relationship between socioeconomics and access to healthcare, and socioeconomic differences between school type may have led to barriers, including transportation, time, and costs, that delayed public athletes from getting into the UCC (17). Yet, there was also no difference between trained public and trained private groups for average days between DOI and first clinic date in both unmatched and matched comparisons (Tables 2 and 4), suggesting that UCC’s partnership with these schools and the flexibility it provides by offering both on-site and virtual appointments may have alleviated any potential differences. These findings also indicate that educating ATs and ADs on the risks of SRCs leads to quicker identification and subsequent appointments.

The percentage of athletes who received academic accommodations after an SRC was significantly greater for both the trained (unmatched and matched) and untrained private school groups compared to the trained public school group. During recovery from an SRC, athletes may have post SRC symptoms that can interfere with their ability to participate and function in the classroom setting (18). Consequently, return to learn protocols and academic accommodations are often provided to the athlete to help reintegrate them into classes but also prevent worsening symptoms (19, 20). Previous research (13) shows that private school students face a particularly high level of academic pressure, potentially due to more rigorous academic programs (9), which could explain why a greater percentage of private groups in this study received more academic accommodations. These additional academic accommodations may have been provided to reduce the burden private group athletes felt about their academic responsibilities or at the request of academic advisors employed at these schools. However, it is important to ensure that all athletes with a sustained SRC receive any appropriate and necessary academic accommodation, regardless of school type attended, to prevent further symptom development.

Limitations This study is not without limitations. All participants in this study were athletes that attended a public or private high school in MDC. Results may not be generalizable to other playing levels, like youth, middle schools, and college, nor to public or private high schools in other counties. Additionally, while other counties may have their own SRC surveillance system, they may not have a program, such as the UConcussion program, that provides ATs with additional SRC training and encourages timely, accurate reporting. A larger sample population in all three groups would have also been beneficial and provided more evidence on the impact of SRC education and protocol on SRC outcomes in the high school setting.

Public and private high school groups trained on the same SRC protocol did not have significantly different SRC outcomes. The untrained private high school group, however, had worse SRC outcomes compared to the public school group, suggesting that SRC outcomes in the high school setting may benefit from education, training, and an established SRC protocol and program and not on whether the school is public or private.

Applications In Sport

An inherent risk of playing sports is injuries, and SRCs are a particularly concerning injury for high school athletes, especially those playing contact sports. Ensuring those responsible for helping to manage SRCs in high schools are educated about SRCs is important, and a collaborative approach to treating and managing SRCs has been recommended (20). As suggested by this study, all high school personnel involved with athletics should be offered SRC management training and education to help improve outcomes of those that sustain an SRC. Additionally, an SRC protocol, like the Six Steps to Play Safe (11), should be established and can include:

• Pre-season baseline testing, using computer-based tests such as ImPACT (12)
• Sideline testing after a potential SRC injury (SCAT5, Balance Error Scoring System (BESS), etc.)
• Post-testing after a suspected SRC (to compare neurocognitive scores to pre-season baseline tests)
• Clinic appointments with a healthcare professional trained in SRC who can evaluate tests and make recommendations
• Gradual RTP and return to learn protocol after the athlete has been examined by a professional and is asymptomatic
• Injury surveillance system reporting by ATs

ACKNOWLEDGEMENTS The authors would like to thank: Dr. Kaplan and the UHealth Sports Medicine Clinic and Staff, the Division of Athletics and Activities for the Miami-Dade County Public Schools, all Miami-Dade County High School Certified Athletic Trainers, previous UConcussion team members, Dr Kester Nedd who served as medical director of the program from 2012 to 2019, current medical director Dr. Abraham Chileuitt, and The Miami Dolphin Foundation for supporting countywide ImPACT testing and educational workshops. We also want to thank David Goldstein and the Goldstein Family for the development of the Countywide Concussion Care Program and their initial and continued support. The project was supported by the University of Miami Clinical and Translational Science Institute.

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An analysis of the factors impacting win percentage and change in win percentage in women’s Division 1 college lacrosse

George Minoso 2024-04-01T07:01:38-05:00 March 22nd, 2024 | General , Research , Sport Training , Sports Management |

Authors: Christiana E. Hilmer 1

1 Department of Economics, San Diego State University, San Diego, CA

Christiana Hilmer, PhD 5500 Campanile Drive San Diego, CA 92182-4485 [email protected] 619-301-9388

Christiana E. Hilmer, PhD, is a Professor of Economics at San Diego State University in San Diego, CA. Her research interests include the economics of sports, applied econometrics, labor economics, and resource and environmental economics.

What factors in women’s NCAA Division 1 college lacrosse led to an increase in win percentage in a single season and a change in win percentage across two consecutive seasons? Do these factors differ between teams at the top and the bottom ends of the win distributions? Using data from the 2023 and 2022 lacrosse seasons, we find that goals, assists, unassisted goals, and participation in the NCAA Championship tournament have a positive impact on win percentage, while opponent’s goals and if the team was new in 2023 have a negative impact on win percentage. The most crucial factor that explains the change in win percentage between the 2022 and 2023 lacrosse seasons is an improvement in the change in total shots ratio, while changes in attacking efficiency and defending efficiency are also important, all together explaining 58% of the variation. Teams at the bottom of the distributions have similar characteristics for both win percentage and change in win percentage as those teams in the middle and the top of the distributions, although there are some slight differences in the magnitudes of the statistically significant variables. These results suggest that lacrosse players and coaches should focus on obtaining additional goals and assists while concurrently minimizing the opponent’s goals to increase win percentage and changes in win percentage.

Keywords : distributional impacts, quantile regression, women’s college lacrosse

Since the advent of sabermetrics pioneered by Bill James and the popularity of Lewis’s (5) Moneyball, the use of statistics to analyze sports has exploded in popularity. Reep and Benjamin (7) applied statistical analysis to team-wide factors in soccer where they investigated how the passing skill and position of a player on the field impacts goals. When analyzing a team’s performance, it is essential to determine which factors lead to a team’s success. Most research in this field has focused on professional sports. Busca et al. (1) examine eleven high-stakes international soccer tournaments to determine where a penalty kick is most likely to be struck. Pelechrinis and Winston (6) develop a framework that is comprised of publicly available data to determine the expected contribution of an individual professional soccer player to the probability of his team winning the game. Alberti et. al. (1) examine goal-scoring patterns in four different professional soccer leagues and find that the majority of goals are scored in the second half of the game with the most goals being scored in the last fifteen minutes of play. Castellano et. al. (3) analyze professional soccer match statistics to determine which factors impact winning, drawing, and losing a game and find that shots, shots on goal, and ball possession are important on the offensive end of the field, while total shots received and shots on target received are important on the defensive end of the field. A notable departure from research that focuses on professional soccer is Joslyn et al. (4), who examines the factors that improve the change in win percentage in men’s Division 1 (D1) college soccer. They find that improving shots, attacking, and defending positively impact the change in win percentage between two consecutive seasons.

This research utilizes the tools found in the team-focused literature from soccer and extends it to lacrosse. Soccer and lacrosse have many similarities, especially regarding possession, assists, goals, and defense. There are also marked differences between the two sports in addition to the obvious one: in soccer the ball is kicked while in lacrosse the ball is played with a net attached to a stick. Lacrosse is a higher-scoring game due to the presence of a 90-second shot clock and defending a women’s lacrosse player is more difficult in lacrosse than it is in soccer. One reason for this is that in lacrosse it is a foul to “move into the path of an opponent without giving the opponent a chance to stop or change direction, and causing contact” (page 51, 2022 and 2023 NCAA Women’s Lacrosse Rules Book (6)), while there is no such rule in soccer. Another reason is due to a rule in women’s lacrosse called shooting space (page 54, NCAA 2022 and 2023 Women’s Lacrosse Rules Book (6)), which states that “with any part of one’s body, guarding the goal outside or inside the goal circle so as to obstruct the free space to goal, between the ball and the goal circle, which denies the attack the opportunity to shoot safely and encourages shooting at a player” while soccer does not have a comparable rule. According to NCAA Statistics (7), the average number of goals per game scored in D1 women’s college lacrosse in 2023 was 12, while the average number of goals per game scored in D1 women’s college soccer in 2023 was 1.39. Another notable difference between lacrosse and soccer is that the offside rules are very different. The offsides rule in lacrosse states that there must be at least five defenders behind their defensive restraining line and at least four offensive players behind their offensive restraining line (page 61, NCAA 2022 and 2023 Women’s Lacrosse Rules Book (6)). The offsides rule in soccer is much less stringent and it states that when in the opponent’s half of the field “the player is not closer to the opponent’s end line than at least two opponents” (page 52, NCAA 2022 and 2023 Soccer Rules Book (7)). These disparities between lacrosse and soccer may result in differences in which factors impact win percentages and changes in win percentages.

This research examines which factors lead to an increase in win percentage and change in win percentage for women’s Division 1 college lacrosse teams. We also seek to determine if these factors differ among teams in the 25th, 50th, and 75th percentiles for win percentage and the change in win percentage. Using data from the 2023 women’s D1 college lacrosse season, we explain 86% of the variation in win percentage. Goals, unassisted goals, and participation in the NCAA Championship tournament have a statistically significant positive impact on win percentage, while opponent’s goals and if the team was new in 2023 have a statistically significant negative impact on win percentage. The most crucial factor explaining the change in win percentage between the 2022 and 2023 lacrosse seasons is an improvement in the change in total shots ratio, while changes in attacking efficiency and defending efficiency are also statistically significant, all together explaining 58% of the variation. The variables that explain both win percentage in a single season and the change in win percentage between seasons are similar between the 25th, 50th, and 75th percentiles. This suggests that teams at the bottom of the distributions should focus on the same factors as those at the top when they seek to improve during a season and between seasons.

Data Source Win percentage was collected from the National Collegiate Athletic Association (NCAA) archives for the 2023 and 2022 seasons. A win was awarded one point while a loss was awarded zero points. Offensive and defensive statistics for the 2023 and 2022 seasons were collected from each University’s women’s lacrosse website housed in the season’s cumulative statistics. It is important to note that these data are provided by individual institutions and therefore the statistical findings of this research is dependent on the accuracy of the information provided by each school. In addition to winning percentage, data was collected on goals, assists, shots, opponent’s goals, opponent’s shots, unassisted goals, ground balls, turnovers, caused turnovers, draw controls, whether the team was new to NCAA D1 lacrosse in the 2023 season, and if the team made the NCAA Championship tournament in 2023. Of the 126 D1 women’s lacrosse teams, 123 had information on every variable listed above.

Variables and Distributions

This analysis aims to determine what factors impact a single season winning percentage and which factors impact the change in win percentage across two consecutive seasons. Figure 1 is a histogram of win percentage for the 2023 women’s lacrosse season. The average win percentage was close to 50% at 48.27%; the minimum win percentage was 0 for the two teams that lost every game during the season, while the maximum win percentage was from a team that won 95.65% of their games. The team with the second-highest win percentage won the 2023 NCAA National Championship tournament.

Summary statistics for the 2023 D1 women’s lacrosse 2023 season are found in table 1. The average number of goals and opponent’s goals nearly offset each other at 211 and 210, respectively. There was an average of 495 shots with a large standard deviation of 105. Below half the goals were aided by an average of 92 assists, while over half of the goals resulted from an average of 119 unassisted goals. There were nearly twice as many turnovers as there were caused turnovers, 7% or a total of 8 teams were new D1 lacrosse teams in 2023, and 24% of the D1 lacrosse teams made the NCAA end-of-season tournament.

Figure 2 contains a histogram of win percentage change, which is constructed by taking the win percentage in the 2023 lacrosse season and subtracting the win percentage in the 2022 lacrosse season. There are fewer observations in the change in win percentage because the seven teams who were new in the 2023 season did not have any statistics for the 2022 season. On average, most teams had a similar win percentage in 2023 as they did in 2022, with an average change in the win percentage of .16. The team with the lowest change in win percentage between the two seasons of -51.47 had a win percentage of 75% in 2022, dropping to 24% in 2023. At the other end of the spectrum, the team with the highest change in win percentage won 12% of their games in 2022 and improved to winning 50% of their games in 2023.

Following Joyce et al. (4), we construct three measures of team success to explain the change in winning percentage: total shots ratio, attaching scoring efficiency, and defending scoring efficiency. The first measure, total shots ratio, is constructed as

The total shots ratio in both 2022 and 2023 is .5, which means, on average, teams are matching their opponent’s shots with their own shots with a range in values from .23 to .7 in 2023 and .3 to .63 in 2022.  This finding for lacrosse compares favorably to what Joyce et al. (4) found for D1 college soccer, where the total shots ratio ranged from .24 to .69 in D1 men’s soccer.

            The second measure of team success is attacking scoring efficiently or goals to shots ratio.

The average attaching scoring efficiency for 2023 and 2022 was .42. This measure had a relatively smaller variability than the total shots ratio, with a minimum of around .3 for both years and a maximum of .5 in 2023 to .58 in 2023. This maximum means that the teams with the highest attacking scoring efficiency earn an average of one goal for every two shots. Being able to convert shots into goals is an essential aspect of winning games. Lacrosse teams are much more likely to convert shots into goals, as Joyce et al. (4) found an average attacking scoring efficiency of .1 or 1 goal for every ten shots in D1 men’s soccer.

The third measure of team success is the defending scoring efficiency, which is contracted as

This final measure determines if teams can prevent opponents from turning shots into goals. The average values for defending scoring efficiency are slightly higher than attaching scoring efficiency, with an average of .43 in 2023 and .44 in 2022. The variability is higher for defending scoring efficiency than attacking scoring efficiency, with a minimum of .31 in 2023 and .34 in 2022 and a maximum of .66 in 2023 and .77 in 2022. Teams that are better at preventing shots from being converted into goals typically have a higher win percentage.

Regression Model The first step in our regression analysis is to empirically estimate the degree to which offensive and defensive statistics impact the win percentage for the 2023 lacrosse season. The win percentage regression model takes the form:

            The second part of the analysis follows Joyce et. al. (4) to determine what factors impact the change in win percentage between the 2023 and 2022 lacrosse seasons.  The regression model is as follows

where ε_i is the error term and i is the individual women’s lacrosse team. As with the individual season analysis, this model is estimated using ordinary linear regression and quantile regression at the 50th, 25th, and 75th percentiles.

Table 3 contains the results for the estimation of equation (4) from the 2023 lacrosse season with robust standard errors in parentheses. Looking first at the results from the ordinary least squares model, 86% of the variation in win percentage is explained by the 11 independent variables. Turning to the variables that are statistically significant, each additional goal results in an increase of .18 in win percentage, while each opponent’s goal results in a decrease of .2 in win percentage, with goals and opponent’s goals nearly offsetting each other. On average, one additional unassisted goal results in an increase of .13 in win percentage. Being a new D1 women’s lacrosse team in 2023 results in a 9 point marginally statistically significant decrease in win percentage relative to teams that have been in the league in previous years. This result suggests that new D1 teams have a difficult time navigating their first year likely due to players and coaches lacking experience and chemistry, making obtaining wins more difficult. Women’s lacrosse teams who participated in the 2023 NCAA Championship Tournament have a statistically significant almost 5 point higher win percentage than those who did not participate in the tournament. This finding is not surprising given that the two ways to get a team into the tournament are to either receive an automatic bid by winning their conference tournament or earn an at-large bid by having a compelling enough record during the regular season and conference playoffs.

The last three columns of table 3 contain quantile regression results at the 50th, 25th, and 75th percentiles of the win percentage distribution. Opponent’s goals are the only statistically significant factor to explain wins across all three percentiles. The magnitude of opponent’s goals is largest at the 25th percentile at -.24 and is -.20 for both the 50th and 75th percentile. Teams at the 25th and 50th percentiles of the win percentage distribution that participates in the NCAA end-of-season tournament has a statistically significant 7 point and 6 point higher win percentage, respectively, relative to those who did not participate, while this variable is not statistically significant at the 75th percentile. This may be because most, 73%, of the tournament participants come from the teams at the top 25% of the win percentage distribution, while most teams at the middle and bottom of the distribution did not participate in the tournament. Aside from this difference, the results are similar between the models at the three points in the win percentage distribution.

Table 4 contains the second part of the regression analysis which estimates equation (5) that attempts to determine what factors impact the change in win percentage between the 2023 and 2022 seasons. The variables contained in this analysis mimic those in Joyce et. al. (4) for men’s D1 college soccer. Looking at the OLS results, teams that had a one unit increase in the change in total shots ratio between the two seasons had a 2.4 increase in the change in win percentage. Teams with a 1 unit increase in the change in attacking efficiency had a 1 unit increase in the change in win percentage, and teams with a one unit increase in the change in defending efficiency decreased the change in win percentage by 1.2 points. The statistical significance between these lacrosse results and those found for soccer by Joslyn et al. (4) are identical, suggesting that even though there are many differences between the two sports, the same factors are important in explaining the change in win percentage between consecutive years. Comparing magnitudes between the two applications is not possible because the estimation methods differed. The statistical significance of the variables included in the quantile regression evaluated at the 50th, 25th, and 75th percentiles were the same as in the OLS regression. The quantile regression performed at the 25th percentile of the change in win percentage had the highest impact for the change in total shots ratio and the change in attacking efficiency, while the change in defending efficiency had the smallest impact. The change in total shots ratio and the change in attacking efficiency had the smallest impact for those teams at the 75th percentile, while the change in defending efficiency had the largest impact for those teams at the 50th percentile. These results suggest that the factors that impact the change in win percentage are similar across teams at the bottom and the top of the change in win percentage distribution, although the marginal impacts differed slightly between the percentiles.

It is not surprising that additional goals led to an increase in win percentage and an increase in opponent’s goals led to a decrease in win percentage. However, it was unanticipated that many of the other offensive and defensive statistics included in the regression were not statistically significant. It is likely that these other factors either lead to the team’s ability to score goals, such as shots, ground balls, and caused turnovers, or lead to the opponent’s goals, such as turnovers. One drawback of this research is that it does not investigate how these other factors impact goals and opponent’s goals. One adage in lacrosse is “win the draw, win the game.” Even though draw controls are not statistically significant in explaining win percentage, there was no information contained in the box scores on how many goals were obtained when the team won the draw control or how many goals were conceded when the team lost the draw control. More detailed information would be needed to investigate this relationship further. Other factors that likely explain win percentage and changes in win percentage such as team chemistry, the presence of a star player, the experience of the players and the coaches, and how different game management strategies, such as the usage of substitutes and quickness of play, are not included because they are difficult to measure, not included in the box scores, or both.

For a lacrosse coach or lacrosse player who is looking to improve win percentage between seasons, it is comforting to note that focusing on improving the changes in total shots ratio, attacking scoring efficiency, and becoming better at defending by decreasing the opponent’s goal-to-shot ratio will lead to an increase in the change in win percentage. One major drawback of this research is that it does not point to the factors that cause improvements in these variables and how they feed into additional goals or fewer conceded goals.

This study is the first to analyze which factors impact win percentage and changes in win percentage for NCAA D1 women’s lacrosse. The regression results suggest that goals, unassisted goals, and those who competed in the NCAA tournament had a positive impact on win percentage, while opponent’s goals and teams that were new in 2023 had a negative impact on win percentage. These factors were similar across the distribution of win percentage at the 25th, 50th, and 75th percentiles. Changes in win percentage between the 2023 and 2022 seasons are positively impacted by the change in the total shots ratio and attacking scoring efficiency and negatively impacted by the change in defending scoring efficiency. Even though there are many differences between lacrosse and soccer, the findings of this research and those of Joyce et. al. (4) that focus on college soccer suggest that the factors that explain changes in win percentage are similar between the two sports. These results also suggest that the statistics that explain win percentage and change in win percentage are similar between teams at the bottom, at the middle, and at the top of the distributions.

Women’s lacrosse programs at the collegiate level as well as at the national level can use these results to determine which factors to focus on when attempting to improve their win percentage within a specific year or over the course of several years. This research suggests that teams should emphasize their efforts in practice and in games on factors that increase goals as well as those factors that prevent goals. The lack of empirical analysis at the collegiate level, especially for women’s sports, can be rectified using available data. Additional publicly available information would make individual game analysis more informative such as how winning a draw control impacts goals as well as how focusing on specific factors such as caused turnovers or increasing assists increases goals and therefore positively impacts a team’s chances of winning.

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Can there be two speeds in a clean peloton? Performance strategies in modern road cycling

George Minoso 2024-02-22T11:24:51-06:00 February 23rd, 2024 | Research , Sport Education , Sport Training , Sports Coaching , Sports Health & Fitness , Sports Medicine , Sports Nutrition |

Authors: Karsten Øvretveit 1

1 K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing,

K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway, PB 8905, N-7491 Trondheim, Norway [email protected]

Karsten Øvretveit, MSc3, is a physiologist and PhD candidate at the Norwegian University of Science and Technology (NTNU). His research areas include genetic disease risk, physical performance, motivational dynamics, and human nutrition.

In the history of professional cycling, riders have always sought competitive advantages. Throughout 20th century, many relied on performance-enhancing drugs (PEDs) which gave rise to a phenomenon called “two-speed cycling”. Throughout its modern era, professional cycling has seen anti-doping efforts repeatedly intensify on the heels of several large doping scandals. Over the past decade, the sport appears to have transitioned away from large-scale systematic doping and towards novel, legal performance-enhancing strategies, facilitated by a close relationship with scientific, technological, and engineering communities. The tools and technologies available to assess the demands of the sport, the capabilities of the riders, and the role of environmental factors such as wind resistance, altitude, and heat are more refined and comprehensive than ever. Teams and riders are now able to leverage these to improve training, recovery, equipment, race tactics and more, often from a very early age. This review explores several key developments in road cycling and their implications for the modern professional peloton.

Key Words: professional cycling; performance-enhancing drugs; marginal gains; performance analysis

The main pack of riders navigating the road in a cycling race, known as the peloton, comprises a wide range of physiological, anthropometrical, technical, and strategical attributes. The role of each rider in a given race is typically based on strengths, weaknesses, and objectives, and can be modified by injuries, fitness level, personal goals, and unexpected in-race developments. The concept of “cycling at two speeds”, cyclisme à deux vitesses, has historically been used to distinguish between chemically enhanced riders and those who ride clean (134). However, despite increasingly stringent doping controls in professional cycling along with a clear shift in doping culture, the concept of two-speed cycling remains. Given the well-documented benefits of performance-enhancing drugs (PEDs), there is an expectation that the intensification of anti-doping measures in professional cycling leads to more homogeneous performance levels in the peloton by reducing the number of artificially enhanced riders. Although this may be a reasonable assumption, it discounts the many substantial advances made in training, nutrition, technology, and strategy, as well as the growing talent pool of potential professionals and the early age at which they begin to seriously structure their training, racing, and recovery. These factors can differ greatly between teams and individual riders and thus help maintain the two-speed phenomenon. This review provides a brief history of the PED culture and use in professional cycling, followed by an examination of some of the key developments in the sport that has helped preserve the two-speed phenomenon in a peloton riding within an increasingly strict anti-doping framework.

The performance-enhanced past of the peloton

Drugs have been used to enhance athletic performance for millennia, stretching back to at least the ancient Olympic Games (16). Cycling as a profession emerged among working-class men who likened endurance sports to physically demanding jobs where the use of drugs to aid performance was considered the right thing to do (58). Indeed, doping has been pervasive in professional cycling for over 150 years, throughout most of which it was either legal or not subject to testing (34). For decades, riders doped to simply be able to do the job – faire le métier (33). Then, athlete health became a concern and a major driving force to regulate, if not outright ban the use of certain substances. Drug testing in the Tour de France (TdF), the most prestigious event on the race calendar, began in 1966. Despite this, amphetamines, cortisone, and steroids remained widespread in the professional peloton. It was also around this time that rumors about the use of blood transfusions in athletes began (60). The year after Raymond Poulidor underwent the first drug test in the TdF, Tom Simpson collapsed on the ascent of Mount Ventoux and later passed away due to an unfortunate combination of alcohol, amphetamines, intense heat, and extreme physical exertion. Although this event brought more attention to the use of stimulants and other drugs in cycling and in sports in general (69), doping would persist for decades to follow. Based on interviews with riders on a professional cycling team at the turn of the millennium, psychiatrist Jean-Christophe Seznec (115) asserted that professional cyclists are not only prone to develop an addiction to PEDs, but also recreational drugs, noting the importance of explicitly acknowledging this risk in order to mitigate it.

When professional cycling entered the 90s, the banned yet at that time undetectable erythropoiesis-stimulating agent (ESA) recombinant human erythropoietin (rHuEPO) arrived in the peloton (101), and performances hit a new level. Increasing circulating erythropoietin (EPO) by illegal means has been perceived by some riders and coaches to give an estimated performance boost, without the term “performance” being strictly defined, of 3% to 20% (31, 100, 134, 138). Interestingly, despite its popularity in the peloton, the research literature on the effects of ESAs such as rHuEPO on endurance performance is equivocal. Its effects on hematological values like hemoglobin concentration ([Hb]) and clinical measurements of power and maximal oxygen uptake (V̇O2max) are well-established, but the real-world benefits are not always clear (116, 123).

There are several aspects of professional cycling that are difficult to account for in experimental studies on exogenous EPO, such as the extremely high fitness level of a peaked professional cyclist and the physiological impact of training and racing on parameters such as Hb . A recent randomized controlled trial found no apparent benefit of EPO on relevant performance markers has sometimes been cited to shed doubt on the true effects of the drug (47). However, this study was done in cyclists with an average V̇O2max of 55.6 mL/kg/min, which is substantially lower than their professional counterparts (124). By his own account, former professional Michael Rasmussen saw his hematocrit (Hct) drop from 41% to 36% following the 2002 Giro d’Italia (98), illustrating how blood composition can be severely perturbed by training and racing. Similar values have been observed in other professionals following participation in Grand Tours (17, 89). Using Rasmussen as an example, using rHuEPO to bring this up to 49%, just below the old 50% limit, would represent a relative Hct increase of 36% and result in improved ability to maintain a much higher intensity in training and racing, and consequently greater exercise-induced adaptations.

Throughout the 90s, Grand Tour riders with supraphysiological Hct would traverse France, Italy, and Spain at impressive speeds until it all seemingly came to an end in 1998. Three days before the start of the 85th edition of the TdF, a Festina team car carrying various PEDs was stopped by customs agents at the French-Belgian border. This event marked the start of what later became known as the Festina affair, a major catalyst in cycling’s transition to a cleaner sport. The wake of this scandal saw an increasing number of calls to action against doping, including by the driver of the Festina car (132), with claims of the sport dying unless drastic action is taken. Subsequent large-scale doping cases such as Operación Puerto and the contents of the USADA’s Reasoned Decision Report (10) served as reminders that PEDs were still present in the peloton and strengthened the resolve of those fighting for a cleaner sport. Although riders are often blamed for the pervasive drug use in cycling, most entered a sport with a lack of top-down anti-doping efforts, leaving them with the difficult choice of either conforming to the culture or competing on unequal terms. One of the most crucial steps towards a cleaner sport is a change in culture among teams and riders. Much, if not most, of the credit should go to the riders themselves, many of which have actively pushed against the use of PEDs for years (46, 50, 59, 85, 130). Today, most doping cases in cycling are among semi-professional riders, whereas the number of riders testing positive at the highest level is approaching zero (88).

Although absence of evidence is not evidence of absence, fewer doping cases at the highest level of cycling suggests that overt, systematic drug use is a thing of the past. Given professional cycling’s checkered history, it would be naïve to think that doping has been eliminated entirely, but the sport does appear to have evolved beyond doping being perceived as all but necessary to gain entry into the professional peloton. Generational shifts not only among riders, but also among governing bodies and team leadership have contributed to an overall firmer stance against doping, removing potentially significant contributors to anti-doping violations (6). There is also indications that the post-Armstrong generation, especially those who started their careers young, are less likely to use PEDs (5), although the evidence is equivocal (64). Additionally, anti-doping technology continues to improve, with recent advances such as gene expression analysis being able to extend the detection window of blood manipulations (28, 133).

Conceptual approaches to legal performance development

It could be argued that the extraordinary performances regularly being on display by the current generation of riders suggest that the dismantling of systematic doping practices has led to progression rather than regression of the sport of cycling. The transition away from prevalent PED use has forced teams and riders to seek out other areas of improvement, some with barely measurable effects, to keep up. Although seeking improvements in many areas is not a new phenomenon in professional cycling, it has received increasing attention over the past decade with the success of Team Sky, now INEOS Grenadiers, and team director, Dave Brailsford, who called this concept “marginal gains”. Brailsford and his team set out to win the TdF within five years with a clean British rider (29). To achieve this, he brought with him the approach he used as a performance director for British Cycling, which had led to considerable success in track cycling. Team Sky was established on the back of British dominance in the Laoshan velodrome during the 2008 Beijing Olympics, where they took home seven gold medals. As he transitioned from the track to the road, Brailsford brought the idea that compiling enough marginal gains could provide a greater performance advantage than PEDs (87).

Although the marginal gain concept came to prominence with Team Sky during one of professional cycling’s most recent avowed shift from banned to legal performance-enhancing strategies, it has been practiced by cyclists since at least the mid-1900s. Italian Fausto Coppi, who rode to multiple victories in the TdF and Giro d’Italia, as well as in one-day classics throughout the 40s and early 50s, was an early adopter of novel diet and training approaches. After World War II, the sport of cycling was anything but advanced and Coppi set out to change that. He worked with Bianchi to develop bikes and other equipment; he adapted his diet to better fuel his riding – not only its contents, but also the timing and amount; and he explored strategies for how to best race as a team (37). Some of these developments would later influence other greats, such as Eddie Merckx, who, among other things, was obsessed with proper bike fit (38). Current director of the French national team, Cyrille Guimard, has also long been known for his application of cutting-edge technology and training methods. One of his former riders, Laurent Fignon, described him as being “right up-to-date. He had files for everything. He was interested in all the lates training methods. Where his protégés were concerned, he would look at the very last detail and even the slightest defect would be corrected. He knew how to ensure everyone had the very best equipment that was on the market: made-to-measure bikes, the newest gadgets.” (32, p. 56).

  The notion that modern riders can surpass past performances solely through legal performance strategies rests on the assumption that these strategies, particularly when combined, are highly effective. Furthermore, a larger pool of athletes and an earlier onset of structured athletic development might amplify these effects. The following section explores the degree of improvement that can be made in the areas of training, nutrition, and technology.

There is not a single anthropometric or physiological characteristic that is completely uniform across high-level cyclists (65, 111). Those with elite potential tend to have stand-out absolute measurements of aerobic fitness and power, but these are attributes that can also be found in cyclists of lower caliber. Elite riders also possess very high power-to-weigh ratios, typically expressed as watts per kilogram (W/kg). An emerging concept that may also distinguish riders of different caliber is durability, i.e., the point and degree of physiological decline during extended exercise (66, 79, 80). Laboratory measurements of key performance determinants such as power-to-weigh ratio, V̇O 2max , cycling economy, critical power, and peak power output provide a detailed physiological profile of each individual rider but cannot accurately predict real-life performance.

Training Strategies

Aided by technology, experience, and insights from a growing body of research, training is more refined, structured, and supervised than before, with most, if not all, training sessions serving a specific purpose. Each rider typically follows an individualized training plan that is carried out under comprehensive monitoring of variables such as heart rate, power output, climate, and terrain. These data, along with laboratory measurements, race outcomes, and even psychological variables, are used to adjust volume, frequency, intensity, and/or modality throughout the season. This allows each rider to absorb as much recoverable training volume as possible to optimize physiological adaptations and peak repeatedly for competition while avoiding overtraining. Whereas virtually every single pedal stroke of the modern rider is quantified and analyzed to guide training, racing, and recovery, riders of the past relied more on “feel”, often opting for subjective rather than objective measurements of output. During the 1987 TdF, Laurent Fignon declared his legs to be “functioning again, more or less”, but did not see the value in monitoring his heart rate, explaining that “I lost my temper with those blasted pulse monitors: I handed mine back so that it wouldn’t tell me anything anymore” (32, p. 182).

Although W/kg is often favored as an indicator of riding capacity and a way to quantify cycling performances, a large V̇O 2max has long been considered a basic requirement of entry into the professional peloton. Values reported for GC contenders are generally comparable between generations, with the lowest value found in the most dominant TdF rider of all time, albeit with an asterisk ( table 1 ). There are a few caveats to these numbers, such as the validity of the actual measurement, most of which are not described in the research literature but rather in media. Moreover, oxygen uptake does not increase in proportion to body mass and scaling V̇O 2max to whole body mass is thus not appropriate when comparing athletes of different body sizes (71). Although some of these values may be exacerbated by PED use, both the baseline level and plasticity of V̇O 2max are under considerable genetic influence (15, 86, 135), and WorldTour levels can be reached without doping in those with sufficient genetic predisposition and appropriate stimulus.

Interestingly, there seems to be a physiological trade-off between efficiency and power, where adaptations towards the latter may attenuate the former (72, 113). This phenomenon was observed in Norwegian cyclist, Oskar Svendsen, who once had the highest V̇O2max ever recorded. Svendsen showed promise early by becoming junior time trial champion with less than three years of training and placing high in Tour de l’Avenir. However, despite an incredible V̇O2max of 96.7 ml/kg/min at 18 years of age, Svendsen never became a WorldTour rider. Although his early retirement at age 20 left his potential at the elite level largely unexplored, the reduction in cycling economy he experienced with increased training load could have been resolved as he matured as a rider, as cyclists appear to become more efficient over the span of their careers with little change in V̇O2max (112). If he remained active, Svendsen may eventually have been able to exploit his incredible baseline to reach the proverbial second speed in the modern peloton without chemical assistance. These insights into Svendsen’s physiological profile not only reveal some of the physiological complexities involved in high-level endurance performance, but also serve as an example of the scientific resources available to modern teams and riders that allows for a level of detail in the assessment and follow-up of athletes never seen before at that level of the sport.

Among the many training-related advances in the modern era is a more systematic approach to altitude training. Altitude-mediated erythropoiesis has long been recognized as an exposure that can produce adaptations that improves performance at sea level, as well as acclimatize athletes to sustain performance in hypobaric conditions. There are several ways to approach altitude training and care should be taken to avoid carrying the detrimental effects of prolonged hypoxic exposure, such as reduced cardiac output (Q̇) due to hypovolemia (117), into competition. Today, professional cycling teams rely on both experience as well as past and emerging research to use altitude as an important preparatory measure in various parts of the season. As the individual responses to hypoxic conditions can vary greatly (93), a large hematological response following real or simulated altitude exposure is an important attribute in modern riders. If done properly, altitude training can induce comparable hematological changes to rHuEPO use (table 2), making it a crucial performance-enhancing strategy in the modern peloton. Increasing [Hb] not only improves V̇O2max by improving the oxygen-carrying capacity of blood (43), it also enables sustained work at a higher fraction of maximal capacity (40) and faster V̇O2 kinetics (18), which can be hugely influential in a peloton with limited interindividual difference in V̇O2max.

A more recent strategy to legally induce hematological adaptations is heat acclimation. Prolonged exposure to heat is associated with both increased plasma volume, which can improve stroke volume and consequently Q̇ and V̇O2max, as well as an expansion of total hemoglobin mass (Hbmass) (91). In fact, light exercise in a heated environment five times per week has been shown to increase Hbmass by 3% – 11% in endurance athletes (90, 103, 107). Due to the logistical challenges and cost related to with altitude camp designs such as live high-train low, heat acclimation training may offer a more accessible strategy for riders and teams with less resources, or an additional stimulus to regular stays at altitude. The mechanistic similarities between synthetic and natural causes of erythropoiesis makes it physiologically possible to harness the benefits of EPO without doping. Voet (132) recounts that pre-scandal Festina riders did not even bring EPO to altitude camps because it was going to be “useless”. Describing his first stay at altitude, formerly enhanced rider, Thomas Dekker, wrote that “[t]he altitude works its magic: the thin air jolts my body into producing extra red blood cells and the Swiss Tour is the first race in ages where I can stay with the pace on the climbs” (25, p. 135), expressing relief that he could hang with the peloton without PEDs. Michele Ferrari, Lance Armstrong’s coach during the height of his career, argues that the effects of EPO on hemoglobin concentration can be achieved through proper altitude training alone (31).

Every rider in the professional peloton possesses rare abilities as cyclists. Given that the sport selects for individuals with above average baseline values of [Hb] and Hct, it may not take much stimulus to maintain a high level. However, compared to simply administering rHuEPO, strategies such as altitude training and heat acclimation are more complex undertakings, partly because of potential drawbacks with that must be accounted for, such as transiently reduced Q̇ and altered dietary requirements. The financial cost associated with prolonged exposure to altitude and/or heat for a professional team is also a considerable barrier, as the finances of teams can differ greatly. In some cases, PED use might simply just be more practical than legal strategies, and not necessarily more powerful.

Improving oxygen delivery and utilization have been main training targets for cyclists throughout most of its history, while resistance training (RT) has been largely neglected. As the impact of both power output and oxygen consumption on cycling performance is intrinsically related to rider weight, maintaining a low body mass has been, and still is, imperative. However, RT with an emphasis on neural adaptations can substantially improve force-generating capacity and reduce the oxygen cost of exercise in athletes without adding unnecessary bulk (51-53, 140). It also helps maintain bone mineral density, which elite cyclists are prone to lose (48, 110). A recent study found that RT with traditional movements and individualized load improved bone mineral density and endurance performance in professional cyclists (126). Moreover, it appeared to improve strength, power, and body composition to a greater degree than short sprint training, a more traditional power training modality for cyclists, supporting the role of structured RT as a part of a professional cyclists overall training program. Indeed, evidence for the benefit of RT on cycling performance has been mounting over the past years (table 3) (62, 102, 104-106, 108, 109, 120, 131, 141). This has contributed to changing the way RT is perceived and applied in the.

An elite physiology is easier to perturb than improve. At the highest level of cycling, large adaptations to training are unlikely to occur in the short term. The full, natural potential of a rider can only be reached via the cumulative effects of proper training and recovery, both of which are highly dependent on proper fueling. Nutrition, body composition, and supplementation

In Jørgen Leth’s classic documentary, “A Sunday in Hell”, Roger De Vlaeminck can be seen consuming a plate of meat with his team before setting out to defend his multiple Paris–Roubaix victories from the previous years in the 1976 edition, with the narrator explaining that “a rare steak is a good breakfast for what lies ahead” (67). This is in stark contrast to the low-residue diet often consumed by riders in the modern peloton (39). A low-residue diet is characterized by a very low fiber content, which can reduce rider weight and consequently improve race performance (36). This diet is usually combined with a very high carbohydrate intake throughout a race to ensure constant glucose availability, and the reduced satiety that can be associated with low-residue diets may even help a rider maintain energy intake during a race. The exact amount differs between riders, with numbers around 100 g of carbohydrate per hour being a rough estimate that may be exceeded considerably on hard days. The recognition of the added performance benefit of increased carbohydrate intake has given rise to the concept of gut training for athletes (56, 78). Racing hard for hours on end for multiple consecutive days with limited glucose availability is guaranteed to hamper performance compared to a well-fueled athlete; as red blood cells do not convert to adenosine triphosphate; blood doping cannot replace bioenergetic fuel.

There are some examples of riders that leveraged nutrition to increase their performance throughout history, such as Fausto Coppi (37), but in the modern era, all riders pay attention and have access to both nutritionists and chefs, both of which are roles that have become integral parts of professional teams. Riders also have access to more knowledge and tools, such as food apps powered by machine learning (121). The days of training hard during the day following by alcohol consumption in the evening and racing on the weekends are gone, but were reportedly common until fairly recently (25, 54). The culmination of evidence- and experience-based diets in professional cycling has led to better fueling strategies and lower body mass in the peloton and perhaps especially among the best riders.

Although described as “thin as rakes” (132, p. 63), the riders of the 90s were heavy by today’s standard. Laurent Fignon (32) explains that the importance of power-to-weight ratio did not become known among the riders before the mid-80s and that he, until that point, paid little attention to diet. Looking at the top 10 finishers of the TdF for the past four decades, starting with the latest edition, suggest that it is becoming more and more of a requirement for the overall GC placing (table 4). Notably, between 1992 and 2022, the average BMI of the top 10 decreased by 8.1%. This trend seems to generally hold across all Grand Tours for the past decades (118).

Supplements such as creatine and beta-alanine have been shown to improve endurance performance, including in cycling (7, 12, 21, 49, 127, 128). Creatine was introduced to the peloton in the mid-90s but was very expensive at the time. Riders who had access to it could consume up to 30 g the day before a long time trial or a mountain stage in hopes of a performance boost (132). Creatine and beta-alanine are now both affordable and widely used, alongside other supplements such as caffeine, electrolytes, nitrates, various vitamins, and minerals, as well as macronutrient supplements such as protein and carbohydrate.

In recent years, a lot of attention has been devoted to exogenous ketones. It is a contentious supplement that has been embraced some of the strongest teams while being recommended against by the Union Cycliste Internationale (UCI) and the Movement for Credible Cycling (MPCC). Ketones, or ketone bodies, are acetyl-CoA-derived metabolites that are produced by the liver under conditions with reduced glucose availability, such as low-carbohydrate diets, fasting, and during or after hard exercise. Ketone bodies such as β-hydroxybutyrate can spare glycogen by inhibiting glycolysis and acting as an alternative fuel in oxidative phosphorylation, which in turn can improve endurance (19). As with the research on other legal and illegal enhancement strategies, the degree to which exogenous ketones translates to improved exercise performance remains to be fully elucidated (24, 92, 94, 96, 125, 139). Although there may be potential drawbacks with isolated ketone supplementation (82), in conjunction with sodium bicarbonate, which is a weak base that has been used for some time in endurance sports (45), ketone supplementation has been shown to improve power output towards the end of a race simulation by 5% (95), although this effect may be unreliable and warrants further study (97).

Much of the hype surrounding some of the proposed effect of ketones as an energy substrate appears unwarranted, but emerging evidence suggest that it may have intriguing properties as a signaling molecule. A few years ago, it was shown that infusion of ketone bodies increased circulating EPO levels in healthy adults (63). The impact of ketones on EPO is supported by the observation that adherence to a ketogenic diet can increase [Hb] and Hct by ~3%, with the caveat this effect is within the biological variation of these markers (83). Recently, Evans et al. (30) found that ingestion of ketone monoester after cycling exercise increased serum EPO concentration, providing further evidence that it may be the signaling effects rather than nutritional value of ketone supplements confers the greatest performance benefit for professional cyclists.

Technology and equipment Science tends to be reductionistic by necessity, whereas a cycling race is much more open-ended. There is, however, a certain cycling event that is performed in highly controlled conditions and relies heavily on technological advances that can serves as a good example of marginal gains in modern road cycling: the hour record. In 1972, Eddy Merckx, perhaps the greatest cyclist of all time, rode a distance of 49.431 km to set a new hour record for the first time since the 1950s. Twelve years later, Francesco Moser breached 50 km with an effort totaling 51.151 km, aided by disc wheels and a skin suit. The following years would see various innovative approaches by riders such as Graeme Obree and Chris Boardman, until the UCI decided to revise the rules in 1994 and again in 2014 (table 5). To set his records, Boardman worked closely with Brailsford’s predecessor in British Cycling, Peter Keen, and then later with Brailsford himself after his retirement, on what would be the beginning of British riders’ marginal gains on the track and later in the peloton (14).

From Voigt’s first attempt to Ganna’s latest, the modern hour record has been improved by over 11%. Although Ganna is a multiple World Time Trial champion and likely one of the most suitable riders to attempt the record, the last person to hold the record before him was Daniel Bigham, the only rider on the list that was never a WorldTour rider. Although an accomplished cyclist in his own right, Bigham’s record is a prime example of how far and fast you can get by maximizing the margins, with his record being set at an average power output approximately 100 watts less than Wiggins. Bigham himself puts his performance down to 50% physiology and 50% equipment (137). One of the main aspects Bigham exploited was aerodynamics; his coefficient of aerodynamic drag (CdA) was ~0.15, which is considerably below what is commonly seen in cyclists, including professionals (41).

Aerodynamics is not only relevant when riding fast around a velodrome for an hour, but also one of the most important things to consider when trying to ride fast on a bike in general. At a riding speed of about 54 km/h, close to the average on a flat TdF stage, approximately 90% of the total resistance is aerodynamic resistance (13, 44). Most of the resistance is caused by the rider himself, with common estimates ranging from 60-82% (74), and the rest by other factors such as equipment (22, 73, 77). The importance of minimizing CdA underlies much of the development of modern bike frames, wheels, handlebars, helmets, clothing, and more. In recent years, there has been less emphasis from manufacturers on getting their bikes down to the UCI weight limit of 6.8 kg in favor of more aerodynamic optimizations. This approach is supported by findings showing that simply opting for aerodynamic rather than light wheels will reduce climbing time on 3% – 6% grade hills (57). Steeper hills favor lighter wheels and WorldTour riders often make specific selections of wheelset, gear ratio, and even frameset based on race or stage profile. Some teams take it a step further, such as Jumbo-Visma, who use a portable aero sensor to measure exact wind conditions on race day and make equipment selections accordingly (81).

Since the inception of professional cycling there have been numerous technological advances and there is still a steady flow of innovations reaching the peloton. Some of these become widely adopted, such as aero-optimized gear; some are providing new alternatives without replacing old ones, such as tubeless tires (riders still use a variety of tubed, tubeless, and tubular tires); and others are replacing without immediately improving a function, such as disc brakes. Technology has also enabled more extensive monitoring of athletes, both on and more recently off the bike. For instance, several teams are now measuring body temperature and hydration status, and by analyzing the individual sodium composition sweat, can select the appropriate supplementary amount of sodium for each rider. During very hot days, riders are often seen wearing cooling gear to keep body temperature down. This can not only keep the riders comfortable, but may also benefit their performance in the race by lowering thermal strain (75).

Although professional cycling continues to benefit from science, technology, and engineering, the UCI have rules and regulations in place that ensures that cycling does not, for better or worse, stray too far away from its origins. Although these are subject to change based on new developments, they sometimes can become more restrictive, such as the recent ban on handlebars narrower than 350mm. Riders with the ability and resources to combine effective performance strategies from training, nutrition, recovery, and technology – perhaps especially strategies with small effects that are more likely to be ignored by others – may find themselves able to ride at a different speed than the rest of the peloton.

Merging the margins

Imagine a gifted and durable athlete with an exceptional ability to consume oxygen across all intensity domains, maintain a low body mass, effectively utilize lactate, absorb and recover from a high training load without injury or illness, handle training and race nutrition, thermoregulate in various climates, and respond well to altitude and heat exposure finding his or her way into cycling early in life. Suppose this young cyclist learns to maintain an aerodynamic position on the bike, pedal with an efficient cadence, move seamlessly through the peloton, avoid accidents, calmly handle the pressure of competition, and execute winning moves. Professional cycling selects for individuals with supraphysiological potential from environments that have allowed this potential to be expressed. Then, it awards those who have made it to the starting line and are able make as many performance determinants as possible come together on race day.

Increased professionalism at the highest level of the sport trickles down to the amateur and junior ranks, exposing up-and-coming cyclists to favorable conditions at an earlier age, leading to greater improvements in physiology, psychology, and race craft. Some riders may show incredible promise in some aspects of racing and struggle with others. Oskar Svendsen, V̇O2max world record holder, undoubtedly had one of the greatest physiological potentials ever seen in a rider. However, he admittedly also had technical and tactical challenges: “Cycling is a monotonous sport, yet so complex and driven by tactics that you won’t win races unless you deliver on all those qualities. I came into the sport with good physical qualities, but I struggled most with the tactics and patterns. I did learn a lot in my senior years on Team Joker though, even if I still had a long way to go. Descending down hills was also something I struggled a lot with, and it sapped much of my energy in races.” (99) Svendsen’s career serves as an example of how cycling is not only a physiological sport, but also technical, tactical, and psychological. Recently retired rider, Richie Porte, described former TdF GC winners Chris Froome and Tadej Pogačar as “psychological beasts” and noted that cycling has become increasingly scientific, which does not suit all riders (35). Modern riders are more methodical, data driven, and regimented than before. This reduces the human element of the sport, to the dismay of those claiming that this will increase predictability. Some researchers in the field have also warned against measuring just for the sake of measuring, and advise that rider data should serve a specific purpose (55).

The widely established routine of constant fueling during training and racing not only acutely increase work capacity but also improves subsequent recovery by preventing the rider from becoming completely depleted. This is in stark contrast to the days when reaching for your bottle during a hard training ride, even if it only contained water, was considered a weakness. Paul Köchli, former coach of riders such as Bernard Hinault and Greg Lemond, once said that the art of cycling is to do the right thing at the right moment (27). This is true not only in the context of a race, but indeed for the professional cyclist’s career as a whole. The effects of proper training, nutrition, and recovery accumulate not only throughout a season, but a whole career, benefitting those who consistently do the right things from early on.

Conclusion and future perspectives

In some ways, modern approaches to improving cycling performance represent a first principles approach to cycling and a fundamental challenge of conventions, within the rules and regulations of UCI. It seems to have restored some of the faith in the sport that was once lost with various doping scandals. Given the measurable impacts of legal performance-enhancing strategies, many of which were previously unknown or overlooked, it could be argued that combining these effects can bring a clean rider’s performance close to, or even surpass, that of an enhanced cyclist, assuming a gifted baseline and sufficient degree of adaptability.

Suggesting that it is possible to win at the highest level in cycling without the use of PEDs is not the same as claiming that the sport is completely clean. As others have pointed out, periods that have previously been perceived as clean have later been shown to be anything but (26). This paper covers some of the key legal advances in road cycling that has contributed to elite performances in the modern peloton, while at the same time acknowledging that illegal strategies may still be present.

Much of what was once considered “marginal gains” have now become common in all professional cycling teams. This represents a shift from a culture of doping to a culture of exhaustive continuous improvement, a lot of which is kept under wraps and some that may even be considered a grey area. Effective anti-doping measures contribute to a more level playing field, but not entirely level. The teams with the most resources often get the most talented riders, allowing them to combine the greatest potential with the best strategies. And even still, there are some who favor optimizing riders and their equipment for weight rather than aerodynamics, ignoring the latter to the extent that it becomes a considerable detriment. In an era of professional cycling where individual performances are influenced by a multitude of human and nonhuman factors, which in combination can have profound effects, the existence of two-speed cycling in a clean peloton is not only logical – it should be expected.

Acknowledgments

This work was supported by the Norwegian University of Science and Technology (NTNU). The author would like to thank Dr. Endre T. Nesse and Dr. Fabio G. Laginestra for their comments and feedback on the manuscript.

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The Real Cause of Losing Sports Officials

George Minoso 2024-02-15T12:01:06-06:00 February 16th, 2024 | Contemporary Sports Issues , General , Sports Coaching , Sports Management , Sports Studies |

Authors: Matthew J Williams D.S.M., M.B.A. M.S.

Department of Education, The University of Virginia’s College at Wise, Wise, VA, USA

Dr. Matthew Williams The University of Virginia’s College at Wise 2001 Greenbriar Drive Bristol, VA 24202

Matthew J. Williams D.S.M., M.B.A., M.S., is an Associate Professor of Sport Management at The University of Virginia’s College at Wise. His areas of research interest include NASCAR, COVID-19, college athletics, professional sports, and sport management issues..

Recreational Sports, Junior Highschool Sports, and Highschool Sports are witnessing across all types of sports a decline in sports officials. Athletic directors in all three levels have seen a steadily declined in sports officials in the last twenty years. But since the COVID-19 Pandemic, the lack of sports officials has increased so rapidly that it could eventually become a nationwide crisis. The pandemic may have caused the decline of sports officials but it was not the only cause. The age of the sports officials has played a role in the decline of the sport’s officials. But the true main cause of losing sports officials has been the lack of respect for the sport’s officials through the behavior of players, coaches, family members, and sports fans.

Keywords Sports Officials, Players, Coaches, Fans, COVID-19 Pandemic, Respect.

Introduction

Recreational Sports, Junior High School Sports, and High School Sports are all witnessing a lack of sports officials all across the United States. There are so many theories out there on why we are losing sports officials so rapidly. If you have attended a sporting event lately and looked at the sports officials, a constant trend you will witness is the sports officials’ increasing ages and the lack of sports officials that are able to cover the sporting events. The repercussions of the lack of sports officials are already being felt. What is the true reason we are losing sports officials? Did COVID-19 Pandemic play a role in the loss of sports officials, the current age of sports officials, or the constant verbal abuse or threats to sports officials?

Even before the 2020 COVID-19 Pandemic Virus, it was apparent to recreational athletic directors, and athletic directors at both junior high and high school that they were already seeing a steady decline in sports officials across the United States over the past decade. The scarcity of officials is a long-running problem in high school sports. (6) From the 2018-19 school year to 2021-22, 32 of 38 states reporting statistics have seen registration numbers of officials drop, according to the National Federation of State High School Associations data. (1) Over the last decade, there has been a steady decline in the amount of referees available. In 2018, the Michigan High School Athletic Association reported that amount of referees available dropped from 12,400 to around 10,000 over the previous decade. (11)

The start of the COVID-19 Pandemic in the spring of 2020 forced a majority of recreational sports, junior high and high school sports across the United States to cease operations and shut down all games until further notice. This action of shutting down all games caused some officials to walk away from officiating. Simply because there were no games for the sports officials to work. As a result of the shutdown, officials had a chance to evaluate if they wanted to return to officiating. So many sports officials did not return to officiate games because of numerous reasons in the fall of 2020 or the spring of 2021. The Alabama High School Athletic Association is working hard to recruit and retain officials in all sports after losing more than 1,000 after the COVID-19 shutdown in the spring of 2020. (2) Washington said the association lost more than 1,100 officials after the COVID-19 shutdown. (2)

In the fall of 2020 and spring of 2021, some of the COVID-19 Pandemic restrictions were lifted and sports returned to somewhat normalcy. However, some officials decided not to return to officiating simply because of their age. There is a concern by some the impact of COVID-19 might hasten the retirement of older officials. (8)

The average age of the sports official was between 45 and 60 and it played a major role in the sports officials’ decision either to continue to be sports officials or not to be a sports official. Officials tend to be near or beyond retirement age the median age for a football referee is 56, according to the National Association of Sports Officials survey. (6) 77% of current officials are over the age of 45, with slightly more than half over the age of 55. (12)

The average age of the sports officials was at least 45 or older during the COVID-19 Pandemic. The COVID-19 Pandemic forced some older sports officials to choose not to return to officiating because simply of the underlying healthcare issues from the COVID-19 Pandemic. Some officials chose not to work during the pandemic because of health/safety concerns, and some of them chose not to return at all. (17) “In talking to some of the state directors, many of these losses are people who were probably on the brink of retirement, and then COVID kind of forced the issue,” explains Dana Pappas, NFHS director of officiating services. (15) The pandemic has also pushed a growing number of referees out, with officials leaving out of fear of getting sick. (16)

During the fall of 2021, some governors across the United States mandated that state employees must be fully vaccinated to prevent and/or limit the spread of the COVID-19 virus. This mandate forced many officials to choose whether to get the COVID-19 vaccination or not get the COVID-19 vaccination. If the sport’s official chose not to take the COVID-19 vaccination due to fears of the side effects of the COVID-19 vaccination or for religious beliefs, they would be banned from officiating junior high school and/or high school games. This mandate forced many officials to stop officiating resulting in a smaller pool of available officials to officiate games. “We already have a shortage of officials, not just in football but other sports,” Weber said”. “That (vaccine requirement) will reduce our numbers, based on what we’re hearing from our officials.” (3) The COVID-19 Pandemic resulted in some officials deciding not to return to officiating, creating an already smaller pool of available officials to officiate games. COVID-19 accelerated the problem, without question. (9)

Today’s parents are more invested financially than ever in their children’s sports careers. Parents are financially supporting their children’s sports careers through travel teams, summer leagues, specialized camps, personal training, and individual lessons. In the hopes that their child will either be drafted into professional sports or earn a college scholarship. Parents being so financially invested has caused an explosion of verbal abuse or threats toward officials from parents. Parents want the best outcomes for their children and are not afraid to voice their opinion to officials either by verbal abuse or threatening officials. Barrett theorized that the rise of travel teams in baseball —not to mention AAU teams in basketball and specialized camps for young football players — has caused parents to feel much more invested in their kids’ athletic careers, both financially and emotionally. (9) The parents feel more emboldened now than ever and are not afraid to voice their opinion verbally toward officials due to the fact they are so financially invested in their children’s sports careers. The parents feel strongly that they deserve the best officials to call the games because they have invested so much financially. “Parents have this sense of entitlement,” Barrett said. “They’re paying so much money, they think they should have better umpires.” (9) “These parents have this mentality of. ‘We pay all this money and travel all this way we expect the best, and referees can’t make mistakes.’ It’s based on society saying it’s okay to yell at people in public if they’re not giving you what they want. It’s asinine.” (13) “The problem is that, as parents spend more time and money on children’s sports, families are “coming to these sporting events with professional-level expectations,” said Jerry Reynolds, a professor of social work at Ball State University who studies the dynamics of youth sports and parent behavior. (7)

Aggressive behavior of abuse toward officials from coaches, players, parents, and fans started well before the COVID-19 Pandemic of 2020. “Before COVID, I felt like this behavior was reaching its peak,” Barlow said. (13) The aggressive behavior toward officials did not stop after the COVID-19 Pandemic was over. But some feel that the abuse of officials has increased resulting in the loss of more officials. Society of today has now become a custom of unruly behavior toward officials, players, and fans. The old saying, I paid my general admission ticket, gives me the right to berate an official, an opposing player, or a coach. This mentality has allowed more aggressiveness toward officials. Parents, coaches, and fans are increasingly aggressive toward officials. (4) People have had seemingly free license to scream, taunt and hurl insults at sporting events — acting out in ways they never would at work, the grocery store, or the dentists office. (14)

Officials have had enough of this type of abusive behavior, which is a major reason why we are losing officials so quickly. No official wants to be verbally abused, harassed, or threatened. Such unruly behavior is the driving force, referees say, behind a nationwide shortage of youth sports officials. (7) We have had the problem of losing officials because of the lack of respect toward officials from parents, family members, and fans well before the COVID-19 Pandemic. The shortfall has persisted for years, as rowdy parents, coaches, and players have created a toxic environment that has driven referees away and hampered the recruitment of new ones, referees say. (7)

The coaches, athletes, parents, family members, and fans of today no longer value or demand sportsmanlike behavior. We now accept unsportsmanlike behavior. Which consists of disrespect or lack of respect for officials through verbal abuse, threats, or harassment. Because we are accepting and allowing this type of behavior from coaches, athletes, parents family members, and fans. This is one of the main reasons why we are losing so many sports officials. “The un-sportsman like conduct of coaches, as well as some parents put people off and they don’t want to come back, they don’t want to return. They get yelled at during their days at work,” added Gittelson. (5) The shortage of officials in high school – and middle school – sports has been a growing concern for several years – in large part due to unsportsmanlike behavior by parents and other adult fans. (10)

Conclusions

The lack of sports officials is becoming a critical situation that recreational athletic directors, junior high school, and high school athletic directors will be facing in the coming years. Some sports officials are deciding to retire because of their age or knowing that their bodies can no longer keep pace with the speed of the game that they are officiating. This is creating a smaller pool of officials from the standpoint that the average age of the sport’s official is at least 45.

The COVID-19 pandemic did play somewhat of a role in reducing of sports officials that we are in right now. The pandemic brought health scares and mandatory COVID-19 vaccinations to some sports officials resulting in these officials making the decision to not return to officiating. But the real cause of the shortage of sports officials is simply the respect that is not given to the sports official by coaches, parents, family members, and fans. The behavior from coaches, parents, family members, and fans of yelling at sports officials, questioning sports officials’ calls, threats of violence towards sports officials, cursing at sports events, and even battery towards sports officials is out of control. No sports official wants to deal with this type of behavior at all nor should this type of behavior be allowed. This is the main reason why we are seeing the pool of sports officials becoming smaller. State legislation, superintendents of schools, principals of schools, and county commissioners need to address this issue of out-of-control behavior toward sports officials. If they do not, we will witness games being canceled, cancellation of seasons, and drastic pay increases that will be demanded by sports officials for the abuse.

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• 31 March 2021

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• Richard Hodson

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The competition to be crowned the fastest, strongest or most technically proficient sportsperson on the planet will once again reach its peak this summer when athletes descend on Tokyo for the Olympic Games. The global pandemic might rule out the throng of enthusiastic spectators that are typical of such an event, but millions will eagerly watch on television as the very best go toe-to-toe.

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Nature 592 , S1 (2021)

doi: https://doi.org/10.1038/d41586-021-00814-5

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• Published: 21 June 2023

The impact of sports participation on mental health and social outcomes in adults: a systematic review and the ‘Mental Health through Sport’ conceptual model

• Narelle Eather   ORCID: orcid.org/0000-0002-6320-4540 1 , 2 ,
• Levi Wade   ORCID: orcid.org/0000-0002-4007-5336 1 , 3 ,
• Aurélie Pankowiak   ORCID: orcid.org/0000-0003-0178-513X 4 &
• Rochelle Eime   ORCID: orcid.org/0000-0002-8614-2813 4 , 5  

Systematic Reviews volume  12 , Article number:  102 ( 2023 ) Cite this article

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Sport is a subset of physical activity that can be particularly beneficial for short-and-long-term physical and mental health, and social outcomes in adults. This study presents the results of an updated systematic review of the mental health and social outcomes of community and elite-level sport participation for adults. The findings have informed the development of the ‘Mental Health through Sport’ conceptual model for adults.

Nine electronic databases were searched, with studies published between 2012 and March 2020 screened for inclusion. Eligible qualitative and quantitative studies reported on the relationship between sport participation and mental health and/or social outcomes in adult populations. Risk of bias (ROB) was determined using the Quality Assessment Tool (quantitative studies) or Critical Appraisal Skills Programme (qualitative studies).

The search strategy located 8528 articles, of which, 29 involving adults 18–84 years were included for analysis. Data was extracted for demographics, methodology, and study outcomes, and results presented according to study design. The evidence indicates that participation in sport (community and elite) is related to better mental health, including improved psychological well-being (for example, higher self-esteem and life satisfaction) and lower psychological ill-being (for example, reduced levels of depression, anxiety, and stress), and improved social outcomes (for example, improved self-control, pro-social behavior, interpersonal communication, and fostering a sense of belonging). Overall, adults participating in team sport had more favorable health outcomes than those participating in individual sport, and those participating in sports more often generally report the greatest benefits; however, some evidence suggests that adults in elite sport may experience higher levels of psychological distress. Low ROB was observed for qualitative studies, but quantitative studies demonstrated inconsistencies in methodological quality.

Conclusions

The findings of this review confirm that participation in sport of any form (team or individual) is beneficial for improving mental health and social outcomes amongst adults. Team sports, however, may provide more potent and additional benefits for mental and social outcomes across adulthood. This review also provides preliminary evidence for the Mental Health through Sport model, though further experimental and longitudinal evidence is needed to establish the mechanisms responsible for sports effect on mental health and moderators of intervention effects. Additional qualitative work is also required to gain a better understanding of the relationship between specific elements of the sporting environment and mental health and social outcomes in adult participants.

Peer Review reports

Introduction

The organizational structure of sport and the performance demands characteristic of sport training and competition provide a unique opportunity for participants to engage in health-enhancing physical activity of varied intensity, duration, and mode; and the opportunity to do so with other people as part of a team and/or club. Participation in individual and team sports have shown to be beneficial to physical, social, psychological, and cognitive health outcomes [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Often, the social and mental health benefits facilitated through participation in sport exceed those achieved through participation in other leisure-time or recreational activities [ 8 , 9 , 10 ]. Notably, these benefits are observed across different sports and sub-populations (including youth, adults, older adults, males, and females) [ 11 ]. However, the evidence regarding sports participation at the elite level is limited, with available research indicating that elite athletes may be more susceptible to mental health problems, potentially due to the intense mental and physical demands placed on elite athletes [ 12 ].

Participation in sport varies across the lifespan, with children representing the largest cohort to engage in organized community sport [ 13 ]. Across adolescence and into young adulthood, dropout from organized sport is common, and especially for females [ 14 , 15 , 16 ], and adults are shifting from organized sports towards leisure and fitness activities, where individual activities (including swimming, walking, and cycling) are the most popular [ 13 , 17 , 18 , 19 ]. Despite the general decline in sport participation with age [ 13 ], the most recent (pre-COVID) global data highlights that a range of organized team sports (such as, basketball, netball volleyball, and tennis) continue to rank highly amongst adult sport participants, with soccer remaining a popular choice across all regions of the world [ 13 ]. It is encouraging many adults continue to participate in sport and physical activities throughout their lives; however, high rates of dropout in youth sport and non-participation amongst adults means that many individuals may be missing the opportunity to reap the potential health benefits associated with participation in sport.

According to the World Health Organization, mental health refers to a state of well-being and effective functioning in which an individual realizes his or her own abilities, is resilient to the stresses of life, and is able to make a positive contribution to his or her community [ 20 ]. Mental health covers three main components, including psychological, emotional and social health [ 21 ]. Further, psychological health has two distinct indicators, psychological well-being (e.g., self-esteem and quality of life) and psychological ill-being (e.g., pre-clinical psychological states such as psychological difficulties and high levels of stress) [ 22 ]. Emotional well-being describes how an individual feels about themselves (including life satisfaction, interest in life, loneliness, and happiness); and social well–being includes an individual’s contribution to, and integration in society [ 23 ].

Mental illnesses are common among adults and incidence rates have remained consistently high over the past 25 years (~ 10% of people affected globally) [ 24 ]. Recent statistics released by the World Health Organization indicate that depression and anxiety are the most common mental disorders, affecting an estimated 264 million people, ranking as one of the main causes of disability worldwide [ 25 , 26 ]. Specific elements of social health, including high levels of isolation and loneliness among adults, are now also considered a serious public health concern due to the strong connections with ill-health [ 27 ]. Participation in sport has shown to positively impact mental and social health status, with a previous systematic review by Eime et al. (2013) indicated that sports participation was associated with lower levels of perceived stress, and improved vitality, social functioning, mental health, and life satisfaction [ 1 ]. Based on their findings, the authors developed a conceptual model (health through sport) depicting the relationship between determinants of adult sports participation and physical, psychological, and social health benefits of participation. In support of Eime’s review findings, Malm and colleagues (2019) recently described how sport aids in preventing or alleviating mental illness, including depressive symptoms and anxiety or stress-related disease [ 7 ]. Andersen (2019) also highlighted that team sports participation is associated with decreased rates of depression and anxiety [ 11 ]. In general, these reviews report stronger effects for sports participation compared to other types of physical activity, and a dose–response relationship between sports participation and mental health outcomes (i.e., higher volume and/or intensity of participation being associated with greater health benefits) when adults participate in sports they enjoy and choose [ 1 , 7 ]. Sport is typically more social than other forms of physical activity, including enhanced social connectedness, social support, peer bonding, and club support, which may provide some explanation as to why sport appears to be especially beneficial to mental and social health [ 28 ].

Thoits (2011) proposed several potential mechanisms through which social relationships and social support improve physical and psychological well-being [ 29 ]; however, these mechanisms have yet to be explored in the context of sports participation at any level in adults. The identification of the mechanisms responsible for such effects may direct future research in this area and help inform future policy and practice in the delivery of sport to enhance mental health and social outcomes amongst adult participants. Therefore, the primary objective of this review was to examine and synthesize all research findings regarding the relationship between sports participation, mental health and social outcomes at the community and elite level in adults. Based on the review findings, the secondary objective was to develop the ‘Mental Health through Sport’ conceptual model.

This review has been registered in the PROSPERO systematic review database and assigned the identifier: CRD42020185412. The conduct and reporting of this systematic review also follows the Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [ 30 ] (PRISMA flow diagram and PRISMA Checklist available in supplementary files ). This review is an update of a previous review of the same topic [ 31 ], published in 2012.

Identification of studies

Nine electronic databases (CINAHL, Cochrane Library, Google Scholar, Informit, Medline, PsychINFO, Psychology and Behavioural Sciences Collection, Scopus, and SPORTDiscus) were systematically searched for relevant records published from 2012 to March 10, 2020. The following key terms were developed by all members of the research team (and guided by previous reviews) and entered into these databases by author LW: sport* AND health AND value OR benefit* OR effect* OR outcome* OR impact* AND psych* OR depress* OR stress OR anxiety OR happiness OR mood OR ‘quality of life’ OR ‘social health’ OR ‘social relation*’ OR well* OR ‘social connect*’ OR ‘social functioning’ OR ‘life satisfac*’ OR ‘mental health’ OR social OR sociolog* OR affect* OR enjoy* OR fun. Where possible, Medical Subject Headings (MeSH) were also used.

Criteria for inclusion/exclusion

The titles of studies identified using this method were screened by LW. Abstract and full text of the articles were reviewed independently by LW and NE. To be included in the current review, each study needed to meet each of the following criteria: (1) published in English from 2012 to 2020; (2) full-text available online; (3) original research or report published in a peer-reviewed journal; (4) provides data on the psychological or social effects of participation in sport (with sport defined as a subset of exercise that can be undertaken individually or as a part of a team, where participants adhere to a common set of rules or expectations, and a defined goal exists); (5) the population of interest were adults (18 years and older) and were apparently healthy. All papers retrieved in the initial search were assessed for eligibility by title and abstract. In cases where a study could not be included or excluded via their title and abstract, the full text of the article was reviewed independently by two of the authors.

Data extraction

For the included studies, the following data was extracted independently by LW and checked by NE using a customized Google Docs spreadsheet: author name, year of publication, country, study design, aim, type of sport (e.g., tennis, hockey, team, individual), study conditions/comparisons, sample size, where participants were recruited from, mean age of participants, measure of sports participation, measure of physical activity, psychological and/or social outcome/s, measure of psychological and/or social outcome/s, statistical method of analysis, changes in physical activity or sports participation, and the psychological and/or social results.

Risk of bias (ROB) assessment

A risk of bias was performed by LW and AP independently using the ‘Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies’ OR the ‘Quality Assessment of Controlled Intervention Studies’ for the included quantitative studies, and the ‘Critical Appraisal Skills Programme (CASP) Checklist for the included qualitative studies [ 32 , 33 ]. Any discrepancies in the ROB assessments were discussed between the two reviewers, and a consensus reached.

The search yielded 8528 studies, with a total of 29 studies included in the systematic review (Fig.  1 ). Tables  1 and 2 provide a summary of the included studies. The research included adults from 18 to 84 years old, with most of the evidence coming from studies targeting young adults (18–25 years). Study samples ranged from 14 to 131, 962, with the most reported psychological outcomes being self-rated mental health ( n  = 5) and depression ( n  = 5). Most studies did not investigate or report the link between a particular sport and a specific mental health or social outcome; instead, the authors’ focused on comparing the impact of sport to physical activity, and/or individual sports compared to team sports. The results of this review are summarized in the following section, with findings presented by study design (cross-sectional, experimental, and longitudinal).

Flow of studies through the review process

Effects of sports participation on psychological well-being, ill-being, and social outcomes

Cross-sectional evidence.

This review included 14 studies reporting on the cross-sectional relationship between sports participation and psychological and/or social outcomes. Sample sizes range from n  = 414 to n  = 131,962 with a total of n  = 239,394 adults included across the cross-sectional studies.

The cross-sectional evidence generally supports that participation in sport, and especially team sports, is associated with greater mental health and psychological wellbeing in adults compared to non-participants [ 36 , 59 ]; and that higher frequency of sports participation and/or sport played at a higher level of competition, are also linked to lower levels of mental distress in adults . This was not the case for one specific study involving ice hockey players aged 35 and over, with Kitchen and Chowhan (2016) Kitchen and Chowhan (2016) reporting no relationship between participation in ice hockey and either mental health, or perceived life stress [ 54 ]. There is also some evidence to support that previous participation in sports (e.g., during childhood or young adulthood) is linked to better mental health outcomes later in life, including improved mental well-being and lower mental distress [ 59 ], even after controlling for age and current physical activity.

Compared to published community data for adults, elite or high-performance adult athletes demonstrated higher levels of body satisfaction, self-esteem, and overall life satisfaction [ 39 ]; and reported reduced tendency to respond to distress with anger and depression. However, rates of psychological distress were higher in the elite sport cohort (compared to community norms), with nearly 1 in 5 athletes reporting ‘high to very high’ distress, and 1 in 3 reporting poor mental health symptoms at a level warranting treatment by a health professional in one study ( n  = 749) [ 39 ].

Four studies focused on the associations between physical activity and sports participation and mental health outcomes in older adults. Physical activity was associated with greater quality of life [ 56 ], with the relationship strongest for those participating in sport in middle age, and for those who cycled in later life (> 65) [ 56 ]. Group physical activities (e.g., walking groups) and sports (e.g., golf) were also significantly related to excellent self-rated health, low depressive symptoms, high health-related quality of life (HRQoL) and a high frequency of laughter in males and females [ 60 , 61 ]. No participation or irregular participation in sport was associated with symptoms of mild to severe depression in older adults [ 62 ].

Several cross-sectional studies examined whether the effects of physical activity varied by type (e.g., total physical activity vs. sports participation). In an analysis of 1446 young adults (mean age = 18), total physical activity, moderate-to-vigorous physical activity, and team sport were independently associated with mental health [ 46 ]. Relative to individual physical activity, after adjusting for covariates and moderate-to-vigorous physical activity (MVPA), only team sport was significantly associated with improved mental health. Similarly, in a cross-sectional analysis of Australian women, Eime, Harvey, Payne (2014) reported that women who engaged in club and team-based sports (tennis or netball) reported better mental health and life satisfaction than those who engaged in individual types of physical activity [ 47 ]. Interestingly, there was no relationship between the amount of physical activity and either of these outcomes, suggesting that other qualities of sports participation contribute to its relationship to mental health and life satisfaction. There was also some evidence to support a relationship between exercise type (ball sports, aerobic activity, weightlifting, and dancing), and mental health amongst young adults (mean age 22 years) [ 48 ], with ball sports and dancing related to fewer symptoms of depression in students with high stress; and weightlifting related to fewer depressive symptoms in weightlifters exhibiting low stress.

Longitudinal evidence

Eight studies examined the longitudinal relationship between sports participation and either mental health and/or social outcomes. Sample sizes range from n  = 113 to n  = 1679 with a total of n  = 7022 adults included across the longitudinal studies.

Five of the included longitudinal studies focused on the relationship between sports participation in childhood or adolescence and mental health in young adulthood. There is evidence that participation in sport in high-school is protective of future symptoms of anxiety (including panic disorder, generalised anxiety disorder, social phobia, and agoraphobia) [ 42 ]. Specifically, after controlling for covariates (including current physical activity), the number of years of sports participation in high school was shown to be protective of symptoms of panic and agoraphobia in young adulthood, but not protective of symptoms of social phobia or generalized anxiety disorder [ 42 ]. A comparison of individual or team sports participation also revealed that participation in either context was protective of panic disorder symptoms, while only team sport was protective of agoraphobia symptoms, and only individual sport was protective of social phobia symptoms. Furthermore, current and past sports team participation was shown to negatively relate to adult depressive symptoms [ 43 ]; drop out of sport was linked to higher depressive symptoms in adulthood compared to those with maintained participation [ 9 , 22 , 63 ]; and consistent participation in team sports (but not individual sport) in adolescence was linked to higher self-rated mental health, lower perceived stress and depressive symptoms, and lower depression scores in early adulthood [ 53 , 58 ].

Two longitudinal studies [ 35 , 55 ], also investigated the association between team and individual playing context and mental health. Dore and colleagues [ 35 ] reported that compared to individual activities, being active in informal groups (e.g., yoga, running groups) or team sports was associated with better mental health, fewer depressive symptoms and higher social connectedness – and that involvement in team sports was related to better mental health regardless of physical activity volume. Kim and James [ 55 ] discovered that sports participation led to both short and long-term improvements in positive affect and life satisfaction.

A study on social outcomes related to mixed martial-arts (MMA) and Brazilian jiu-jitsu (BJJ) showed that both sports improved practitioners’ self-control and pro-social behavior, with greater improvements seen in the BJJ group [ 62 ]. Notably, while BJJ reduced participants’ reported aggression, there was a slight increase in MMA practitioners, though it is worth mentioning that individuals who sought out MMA had higher levels of baseline aggression.

Experimental evidence

Six of the included studies were experimental or quasi-experimental. Sample sizes ranged from n  = 28 to n  = 55 with a total of n  = 239 adults included across six longitudinal studies. Three studies involved a form of martial arts (such as judo and karate) [ 45 , 51 , 52 ], one involved a variety of team sports (such as netball, soccer, and cricket) [ 34 ], and the remaining two focused on badminton [ 57 ] and handball [ 49 ].

Brinkley and colleagues [ 34 ] reported significant effects on interpersonal communication (but not vitality, social cohesion, quality of life, stress, or interpersonal relationships) for participants ( n  = 40) engaging in a 12-week workplace team sports intervention. Also using a 12-week intervention, Hornstrup et al. [ 49 ] reported a significant improvement in mental energy (but not well-being or anxiety) in young women (mean age = 24; n  = 28) playing in a handball program. Patterns et al. [ 57 ] showed that in comparison to no exercise, participation in an 8-week badminton or running program had no significant improvement on self-esteem, despite improvements in perceived and actual fitness levels.

Three studies examined the effect of martial arts on the mental health of older adults (mean ages 79 [ 52 ], 64 [ 51 ], and 70 [ 45 ] years). Participation in Karate-Do had positive effects on overall mental health, emotional wellbeing, depression and anxiety when compared to other activities (physical, cognitive, mindfulness) and a control group [ 51 , 52 ]. Ciaccioni et al. [ 45 ] found that a Judo program did not affect either the participants’ mental health or their body satisfaction, citing a small sample size, and the limited length of the intervention as possible contributors to the findings.

Qualitative evidence

Three studies interviewed current or former sports players regarding their experiences with sport. Chinkov and Holt [ 41 ] reported that jiu-jitsu practitioners (mean age 35 years) were more self-confident in their lives outside of the gym, including improved self-confidence in their interactions with others because of their training. McGraw and colleagues [ 37 ] interviewed former and current National Football League (NFL) players and their families about its impact on the emotional and mental health of the players. Most of the players reported that their NFL career provided them with social and emotional benefits, as well as improvements to their self-esteem even after retiring. Though, despite these benefits, almost all the players experienced at least one mental health challenge during their career, including depression, anxiety, or difficulty controlling their temper. Some of the players and their families reported that they felt socially isolated from people outside of the national football league.

Through a series of semi-structured interviews and focus groups, Thorpe, Anders [ 40 ] investigated the impact of an Aboriginal male community sporting team on the health of its players. The players reported they felt a sense of belonging when playing in the team, further noting that the social and community aspects were as important as the physical health benefits. Participating in the club strengthened the cultural identity of the players, enhancing their well-being. The players further noted that participation provided them with enjoyment, stress relief, a sense of purpose, peer support, and improved self-esteem. Though they also noted challenges, including the presence of racism, community conflict, and peer-pressure.

Quality of studies

Full details of our risk of bias (ROB) results are provided in Supplementary Material A . Of the three qualitative studies assessed using the Critical Appraisal Skills Program (CASP), all three were deemed to have utilised and reported appropriate methodological standards on at least 8 of the 10 criteria. Twenty studies were assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, with all studies clearly reporting the research question/s or objective/s and study population. However, only four studies provided a justification for sample size, and less than half of the studies met quality criteria for items 6, 7, 9, or 10 (and items 12 and 13 were largely not applicable). Of concern, only four of the observational or cohort studies were deemed to have used clearly defined, valid, and reliable exposure measures (independent variables) and implemented them consistently across all study participants. Six studies were assessed using the Quality Assessment of Controlled Intervention Studies, with three studies described as a randomized trial (but none of the three reported a suitable method of randomization, concealment of treatment allocation, or blinding to treatment group assignment). Three studies showed evidence that study groups were similar at baseline for important characteristics and an overall drop-out rate from the study < 20%. Four studies reported high adherence to intervention protocols (with two not reporting) and five demonstrated that.study outcomes were assessed using valid and reliable measures and implemented consistently across all study participants. Importantly, researchers did not report or have access to validated instruments for assessing sport participation or physical activity amongst adults, though most studies provided psychometrics for their mental health outcome measure/s. Only one study reported that the sample size was sufficiently powered to detect a difference in the main outcome between groups (with ≥ 80% power) and that all participants were included in the analysis of results (intention-to-treat analysis). In general, the methodological quality of the six randomised studies was deemed low.

Initially, our discussion will focus on the review findings regarding sports participation and well-being, ill-being, and psychological health. However, the heterogeneity and methodological quality of the included research (especially controlled trials) should be considered during the interpretation of our results. Considering our findings, the Mental Health through Sport conceptual model for adults will then be presented and discussed and study limitations outlined.

Sports participation and psychological well-being

In summary, the evidence presented here indicates that for adults, sports participation is associated with better overall mental health [ 36 , 46 , 47 , 59 ], mood [ 56 ], higher life satisfaction [ 39 , 47 ], self-esteem [ 39 ], body satisfaction [ 39 ], HRQoL [ 60 ], self-rated health [ 61 ], and frequency of laughter [ 61 ]. Sports participation has also shown to be predictive of better psychological wellbeing over time [ 35 , 53 ], higher positive affect [ 55 ], and greater life satisfaction [ 55 ]. Furthermore, higher frequency of sports participation and/or sport played at a higher level of competition, have been linked to lower levels of mental distress, higher levels of body satisfaction, self-esteem, and overall life satisfaction in adults [ 39 ].

Despite considerable heterogeneity of sports type, cross-sectional and experimental research indicate that team-based sports participation, compared to individual sports and informal group physical activity, has a more positive effect on mental energy [ 49 ], physical self-perception [ 57 ], and overall psychological health and well-being in adults, regardless of physical activity volume [ 35 , 46 , 47 ]. And, karate-do benefits the subjective well-being of elderly practitioners [ 51 , 52 ]. Qualitative research in this area has queried participants’ experiences of jiu-jitsu, Australian football, and former and current American footballers. Participants in these sports reported that their participation was beneficial for psychological well-being [ 37 , 40 , 41 ], improved self-esteem [ 37 , 40 , 41 ], and enjoyment [ 37 ].

Sports participation and psychological ill-being

Of the included studies, n  = 19 examined the relationship between participating in sport and psychological ill-being. In summary, there is consistent evidence that sports participation is related to lower depression scores [ 43 , 48 , 61 , 62 ]. There were mixed findings regarding psychological stress, where participation in childhood (retrospectively assessed) was related to lower stress in young adulthood [ 41 ], but no relationship was identified between recreational hockey in adulthood and stress [ 54 ]. Concerning the potential impact of competing at an elite level, there is evidence of higher stress in elite athletes compared to community norms [ 39 ]. Further, there is qualitative evidence that many current or former national football league players experienced at least one mental health challenge, including depression, anxiety, difficulty controlling their temper, during their career [ 37 ].

Evidence from longitudinal research provided consistent evidence that participating in sport in adolescence is protective of symptoms of depression in young adulthood [ 43 , 53 , 58 , 63 ], and further evidence that participating in young adulthood is related to lower depressive symptoms over time (6 months) [ 35 ]. Participation in adolescence was also protective of manifestations of anxiety (panic disorder and agoraphobia) and stress in young adulthood [ 42 ], though participation in young adulthood was not related to a more general measure of anxiety [ 35 ] nor to changes in negative affect [ 55 ]). The findings from experimental research were mixed. Two studies examined the effect of karate-do on markers of psychological ill-being, demonstrating its capacity to reduce anxiety [ 52 ], with some evidence of its effectiveness on depression [ 51 ]. The other studies examined small-sided team-based games but showed no effect on stress or anxiety [ 34 , 49 ]. Most studies did not differentiate between team and individual sports, though one study found that adolescents who participated in team sports (not individual sports) in secondary school has lower depression scores in young adulthood [ 58 ].

Sports participation and social outcomes

Seven of the included studies examined the relationship between sports participation and social outcomes. However, very few studies examined social outcomes or tested a social outcome as a potential mediator of the relationship between sport and mental health. It should also be noted that this body of evidence comes from a wide range of sport types, including martial arts, professional football, and workplace team-sport, as well as different methodologies. Taken as a whole, the evidence shows that participating in sport is beneficial for several social outcomes, including self-control [ 50 ], pro-social behavior [ 50 ], interpersonal communication [ 34 ], and fostering a sense of belonging [ 40 ]. Further, there is evidence that group activity, for example team sport or informal group activity, is related to higher social connectedness over time, though analyses showed that social connectedness was not a mediator for mental health [ 35 ].

There were conflicting findings regarding social effects at the elite level, with current and former NFL players reporting that they felt socially isolated during their career [ 37 ], whilst another study reported no relationship between participation at the elite level and social dysfunction [ 39 ]. Conversely, interviews with a group of indigenous men revealed that they felt as though participating in an all-indigenous Australian football team provided them with a sense of purpose, and they felt as though the social aspect of the game was as important as the physical benefits it provides [ 40 ].

Mental health through sport conceptual model for adults

The ‘Health through Sport’ model provides a depiction of the determinants and benefits of sports participation [ 31 ]. The model recognises that the physical, mental, and social benefits of sports participation vary by the context of sport (e.g., individual vs. team, organized vs. informal). To identify the elements of sport which contribute to its effect on mental health outcomes, we describe the ‘Mental Health through Sport’ model (Fig.  2 ). The model proposes that the social and physical elements of sport each provide independent, and likely synergistic contributions to its overall influence on mental health.

The Mental Health through Sport conceptual model

The model describes two key pathways through which sport may influence mental health: physical activity, and social relationships and support. Several likely moderators of this effect are also provided, including sport type, intensity, frequency, context (team vs. individual), environment (e.g., indoor vs. outdoor), as well as the level of competition (e.g., elite vs. amateur).

The means by which the physical activity component of sport may influence mental health stems from the work of Lubans et al., who propose three key groups of mechanisms: neurobiological, psychosocial, and behavioral [ 64 ]. Processes whereby physical activity may enhance psychological outcomes via changes in the structural and functional composition of the brain are referred to as neurobiological mechanisms [ 65 , 66 ]. Processes whereby physical activity provides opportunities for the development of self-efficacy, opportunity for mastery, changes in self-perceptions, the development of independence, and for interaction with the environment are considered psychosocial mechanisms. Lastly, processes by which physical activity may influence behaviors which ultimately affect psychological health, including changes in sleep duration, self-regulation, and coping skills, are described as behavioral mechanisms.

Playing sport offers the opportunity to form relationships and to develop a social support network, both of which are likely to influence mental health. Thoits [ 29 ] describes 7 key mechanisms by which social relationships and support may influence mental health: social influence/social comparison; social control; role-based purpose and meaning (mattering); self-esteem; sense of control; belonging and companionship; and perceived support availability [ 29 ]. These mechanisms and their presence within a sporting context are elaborated below.

Subjective to the attitudes and behaviors of individuals in a group, social influence and comparison may facilitate protective or harmful effects on mental health. Participants in individual or team sport will be influenced and perhaps steered by the behaviors, expectations, and norms of other players and teams. When individual’s compare their capabilities, attitudes, and values to those of other participants, their own behaviors and subsequent health outcomes may be affected. When others attempt to encourage or discourage an individual to adopt or reject certain health practices, social control is displayed [ 29 ]. This may evolve as strategies between players (or between players and coach) are discussion and implemented. Likewise, teammates may try to motivate each another during a match to work harder, or to engage in specific events or routines off-field (fitness programs, after game celebrations, attending club events) which may impact current and future physical and mental health.

Sport may also provide behavioral guidance, purpose, and meaning to its participants. Role identities (positions within a social structure that come with reciprocal obligations), often formed as a consequence of social ties formed through sport. Particularly in team sports, participants come to understand they form an integral part of the larger whole, and consequently, they hold certain responsibility in ensuring the team’s success. They have a commitment to the team to, train and play, communicate with the team and a potential responsibility to maintain a high level of health, perform to their capacity, and support other players. As a source of behavioral guidance and of purpose and meaning in life, these identities are likely to influence mental health outcomes amongst sport participants.

An individual’s level of self-esteem may be affected by the social relationships and social support provided through sport; with improved perceptions of capability (or value within a team) in the sporting domain likely to have positive impact on global self-esteem and sense of worth [ 64 ]. The unique opportunities provided through participation in sport, also allow individuals to develop new skills, overcome challenges, and develop their sense of self-control or mastery . Working towards and finding creative solutions to challenges in sport facilitates a sense of mastery in participants. This sense of mastery may translate to other areas of life, with individual’s developing the confidence to cope with varied life challenges. For example, developing a sense of mastery regarding capacity to formulate new / creative solutions when taking on an opponent in sport may result in greater confidence to be creative at work. Social relationships and social support provided through sport may also provide participants with a source of belonging and companionship. The development of connections (on and off the field) to others who share common interests, can build a sense of belonging that may mediate improvements in mental health outcomes. Social support is often provided emotionally during expressions of trust and care; instrumentally via tangible assistance; through information such as advice and suggestions; or as appraisal such feedback. All forms of social support provided on and off the field contribute to a more generalised sense of perceived support that may mediate the effect of social interaction on mental health outcomes.

Participation in sport may influence mental health via some combination of the social mechanisms identified by Thoits, and the neurobiological, psychosocial, and behavioral mechanisms stemming from physical activity identified by Lubans [ 29 , 64 ]. The exact mechanisms through which sport may confer psychological benefit is likely to vary between sports, as each sport varies in its physical and social requirements. One must also consider the social effects of sports participation both on and off the field. For instance, membership of a sporting team and/or club may provide a sense of identity and belonging—an effect that persists beyond the immediacy of playing the sport and may have a persistent effect on their psychological health. Furthermore, the potential for team-based activity to provide additional benefit to psychological outcomes may not just be attributable to the differences in social interactions, there are also physiological differences in the requirements for sport both within (team vs. team) and between (team vs. individual) categories that may elicit additional improvements in psychological outcomes. For example, evidence supports that exercise intensity moderates the relationship between physical activity and several psychological outcomes—supporting that sports performed at higher intensity will be more beneficial for psychological health.

Limitations and recommendations

There are several limitations of this review worthy of consideration. Firstly, amongst the included studies there was considerable heterogeneity in study outcomes and study methodology, and self-selection bias (especially in non-experimental studies) is likely to influence study findings and reduce the likelihood that study participants and results are representative of the overall population. Secondly, the predominately observational evidence included in this and Eime’s prior review enabled us to identify the positive relationship between sports participation and social and psychological health (and examine directionality)—but more experimental and longitudinal research is required to determine causality and explore potential mechanisms responsible for the effect of sports participation on participant outcomes. Additional qualitative work would also help researchers gain a better understanding of the relationship between specific elements of the sporting environment and mental health and social outcomes in adult participants. Thirdly, there were no studies identified in the literature where sports participation involved animals (such as equestrian sports) or guns (such as shooting sports). Such studies may present novel and important variables in the assessment of mental health benefits for participants when compared to non-participants or participants in sports not involving animals/guns—further research is needed in this area. Our proposed conceptual model also identifies several pathways through which sport may lead to improvements in mental health—but excludes some potentially negative influences (such as poor coaching behaviors and injury). And our model is not designed to capture all possible mechanisms, creating the likelihood that other mechanisms exist but are not included in this review. Additionally, an interrelationship exits between physical activity, mental health, and social relationships, whereby changes in one area may facilitate changes in the other/s; but for the purpose of this study, we have focused on how the physical and social elements of sport may mediate improvements in psychological outcomes. Consequently, our conceptual model is not all-encompassing, but designed to inform and guide future research investigating the impact of sport participation on mental health.

The findings of this review endorse that participation in sport is beneficial for psychological well-being, indicators of psychological ill-being, and social outcomes in adults. Furthermore, participation in team sports is associated with better psychological and social outcomes compared to individual sports or other physical activities. Our findings support and add to previous review findings [ 1 ]; and have informed the development of our ‘Mental Health through Sport’ conceptual model for adults which presents the potential mechanisms by which participation in sport may affect mental health.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

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We would like to acknowledge the work of the original systematic review conducted by Eime, R. M., Young, J. A., Harvey, J. T., Charity, M. J., and Payne, W. R. (2013).

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All authors contributed to the conducting of this study and reporting the findings. The titles of studies identified were screened by LW, and abstracts and full text articles reviewed independently by LW and NE. For the included studies, data was extracted independently by LW and checked by NE, and the risk of bias assessment was performed by LW and AP independently. All authors have read and approved the final version of the manuscript and agree with the order of presentation of the authors.

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Eather, N., Wade, L., Pankowiak, A. et al. The impact of sports participation on mental health and social outcomes in adults: a systematic review and the ‘Mental Health through Sport’ conceptual model. Syst Rev 12 , 102 (2023). https://doi.org/10.1186/s13643-023-02264-8

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The original article was published in Sports Medicine - Open 2023 9 :110

The Original Research Article to this article has been published in Sports Medicine - Open 2023 9 :55

Comment on: Exploring the Low Force-High Velocity Domain of the Force–Velocity Relationship in Acyclic Lower-Limb Extensions

The original article was published in Sports Medicine - Open 2023 9 :55

The Letter to the Editor to this article has been published in Sports Medicine - Open 2023 9 :111

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Article Contents

Introduction, literature search, physeal injuries and growth disturbance, residual problems after injury in athletes, outcomes of operative management of common sports injuries, conclusions.

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Sport injuries: a review of outcomes

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Nicola Maffulli, Umile Giuseppe Longo, Nikolaos Gougoulias, Dennis Caine, Vincenzo Denaro, Sport injuries: a review of outcomes, British Medical Bulletin , Volume 97, Issue 1, March 2011, Pages 47–80, https://doi.org/10.1093/bmb/ldq026

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Injuries can counter the beneficial aspects related to sports activities if an athlete is unable to continue to participate because of residual effects of injury. We provide an updated synthesis of existing clinical evidence of long-term follow-up outcome of sports injuries. A systematic computerized literature search was conducted on following databases were accessed: PubMed, Medline, Cochrane, CINAHL and Embase databases. At a young age, injury to the physis can result in limb deformities and leg-length discrepancy. Weight-bearing joints including the hip, knee and ankle are at risk of developing osteoarthritis (OA) in former athletes, after injury or in the presence of malalignment, especially in association with high impact sport. Knee injury is a risk factor for OA. Ankle ligament injuries in athletes result in incomplete recovery (up to 40% at 6 months), and OA in the long term (latency period more than 25 years). Spine pathologies are associated more commonly with certain sports (e.g. wresting, heavy-weight lifting, gymnastics, tennis, soccer). Evolution in arthroscopy allows more accurate assessment of hip, ankle, shoulder, elbow and wrist intra-articular post-traumatic pathologies, and possibly more successful management. Few well-conducted studies are available to establish the long-term follow-up of former athletes. To assess whether benefits from sports participation outweigh the risks, future research should involve questionnaires regarding the health-related quality of life in former athletes, to be compared with the general population.

Participation in sports is widespread all over the world, 1 with well-described physical, psychological and social consequences for involved athletes. 2–5 The benefits associated with physical activity in both youth and elderly are well documented. 2 , 6–8 Regular participation in sports is associated with a better quality of life and reduced risk of several diseases, 1 , 9 allowing people involved to improve cardiovascular health. 10 , 11 Both individual and team sports are associated with favourable physical and physiological changes consisting of decreased percentage of body fat 12 and increased muscular strength, endurance and power. 13 , 14 Moreover, regular participation in high-volume impact-loading and running-based sports (such as basketball, gymnastics, tennis, soccer and distance running) is associated with enhanced whole-body and regional bone mineral content and density, 14 , 15 whereas physical inactivity is associated with obesity and coronary heart disease. 16 Sports are associated with several psychological and emotional benefits. 7 , 17 , 18 First of all, there is a strong relationship between the development of positive self-esteem, due to testing of self in a context of sport competition, 19 reduced stress, anxiety and depression. 20 Physical activities also contribute to social development of athletes, prosocial behaviour, fair play and sportspersonship 21 and personal responsibility. 22

Engaging in sports activities has numerous health benefits, but also carries the risk of injury. 7 , 23 , 24 At every age, competitive and recreational athletes sustain a wide variety of soft tissue, bone, ligament, tendon and nerve injuries, caused by direct trauma or repetitive stress. 25–35 Different sports are associated with different patterns and types of injuries, whereas age, gender and type of activity (e.g. competitive versus practice) influence the prevalence of injuries. 7 , 36 , 37

Injuries in children and adolescents, who often tend to focus on high performance in certain disciplines and sports, 24 include susceptibility to growth plate injury, nonlinearity of growth, limited thermoregulatory capacity and maturity-associated variation. 9 In the immature skeleton, growth plate injury is possible 38 and apophysitis is common. The most common sites are at the knee (Osgood-Schlatter lesion), the heel (Sever's lesion) and the elbow. 39 Certain contact sports, such as rugby, for example, are associated with 5.2 injuries per 1000 total athletic exposures in high school children (usually boys). These were more common during competition compared with training and fractures accounted for 16% of these injuries, whereas concussions (15.8%) and ligament sprains (15.7%) were almost as common. 40

Sports trauma commonly affects joints of the extremities (knee, ankle, hip, shoulder, elbow, wrist) or the spine. Knee injuries are among the most common. Knee trauma can result in meniscal and chondral lesions, sometimes in combination with cruciate ligament injuries. 37 Ankle injuries constitute 21% of all sports injuries. 41 Ankle ligament injuries are more commonly (83%) diagnosed as ligament sprains (incomplete tears), and are common in sports such as basketball and volleyball. Ankle injuries occur usually during competition and in the majority of cases, athletes can return to sports within a week. 42 Hip labral injuries have drawn attention in recent years with the advent of hip arthroscopy. 43 , 44 Upper extremity syndromes caused by a single stress or by repetitive microtrauma occur in a variety of sports. Overhead throwing, long-distance swimming, bowling, golf, gymnastics, basketball, volleyball and field events can repetitively stress the hand, wrist, elbow and shoulder. Shoulder and elbow problems are common in the overhead throwing athlete whereas elbow injuries remain often unrecognized in certain sports. 45 Hand and wrist trauma accounts for 3–9% of all athletic injuries. 46 Wrist trauma can affect the triangular fibrocartilage complex 47 or cause scaphoid fractures, 48 whereas overuse problems (e.g. tenosynovitis) are not uncommon. 49 Spinal problems can range from lumbar disc herniation, 39–42 to fatigue fractures of the pars interarticularis, 50 and ‘catastrophic’ cervical spine injuries. 51

Thus, in addition to the beneficial aspects related to sports activities, injuries can counter these if an athlete is unable to continue to participate because of residual effects of injury. Do injuries in children, adolescents and young adults have long-term consequences? What are the outcomes of the most commonly performed surgical procedures? The aim of this review is to provide an updated synthesis of existing clinical evidence of long-term follow-up outcome of sports injuries.

An initial pilot Pubmed search using the keywords ‘sports’, ‘injury’, ‘injuries’, ‘athletes’, ‘outcome’, ‘long term’, was performed. From 1467 abstracts that were retrieved and scanned we identified the thematic topics (types of injury, management, area of the body involved) of the current review, listed below:

Then a more detailed search of PubMed, Medline, Cochrane, CINAHL and Embase databases followed. We used combinations of the keywords: ‘sport’, ‘sports’, ‘youth sports’, ‘young athletes’, ‘former athletes’, ‘children’, ‘skeletally immature’, ‘adolescent’, ‘paediatric’, ‘pediatric’, ‘physeal’, ‘epiphysis’, ‘epiphyseal injuries’, ‘hip’, ‘knee’, ‘ankle’, ‘spine’, ‘spinal’, ‘shoulder’, ‘elbow’, ‘wrist’, ‘football players’, ‘football’, ‘soccer’, ‘tennis’, ‘swimmers’, ‘swimming’, ‘divers’, ‘wrestlers’, ‘wrestling’, ‘cricket’, ‘gymnastics’, ‘skiers’, ‘baseball’, ‘basketball’, ‘osteoarthritis’, ‘former athletes’, ‘strain’, ‘contusion’, ‘distortion’, ‘injury’, ‘injuries’, ‘trauma’, ‘drop out’, ‘dropping out’, ‘attrition’, ‘young’, ‘ youth’, ‘sprain’, ‘ligament’, ‘ACL’, ‘cruciate ligament’, ‘meniscus’, ‘meniscal’, ‘chondral’, ‘labrum’, ‘labral’, ‘reconstruction’, ‘arthroscopy’, ‘throwing’, ‘overhead’, ‘rotator cuff’, ‘TFCC’, ‘scaphoid’, ‘osteoarthritis’, ‘arthritis’, ‘long term’, ‘follow-up’ and ‘athlete’. The most recent search was performed during the second week of November 2009.

Osteoarthritis (OA) in former athletes

Spine problems in former athletes

Knee injury and OA

Ankle ligament injury and OA

Residual upper limb symptoms in the ‘overhead’ athlete

Meniscectomy and oa, meniscal repair in athletes.

Anterior cruciate ligament (ACL) reconstruction and OA

ACL reconstruction in children

Ankle arthroscopy in athletes, hip arthroscopy in athletes.

Operative management of shoulder injuries in athletes (focusing on surgery for instability and labral tears)

Operative management of wrist injuries in athletes (focusing on triquetral fibrocartilage complex, TFCC, injuries and scaphoid fractures)

Given the different types of sports injuries in terms of location in the body, several searches were carried out. The search was limited to articles published in peer-reviewed journals.

From a total of 2596 abstracts that were scanned, 1247 studies were irrelevant to the subject and were excluded. The remaining studies were categorized in the topics identified earlier. We excluded from our investigation case reports, letter to editors and articles not specifically reporting outcomes, as well as ‘kin’ studies (studies reporting on the same patients' population). The most recent study or the study with the longest follow-up was included. In some topics of particular importance, such as the effect of knee injuries (given their frequency), we included long-term studies reporting not only on athletes, but also on the general population (usually in these studies a very high proportion on sports injuries is included). Regarding knee injuries in adults, we included articles with follow-up more than 10 years.

Given the linguistic capabilities of the research team, we considered publications in English, Italian, French, German, Spanish and Portuguese.

A concern regarding children's participation in sports is that the tolerance limits of the physis may be exceeded by the mechanical stresses of sports such as football and hockey or by the repetitive physical loading required in sports such as baseball, gymnastics and distance running. 52 Unfortunately, what is known about the frequency of acute sport-related physeal injuries is derived primarily from case reports and case series data. In a previous systematic review on the frequency and characteristics of sports-related growth plate injuries affecting children and youth, we found that 38.3% of 2157 acute cases were sport related and among these 14.9% were associated with growth disturbance. 24 These injuries were incurred in a variety of sports, although football is the sport most often reported. 53

There are accumulating reports of stress-related physeal injuries affecting young athletes in a variety of sports, including baseball, basketball, climbing, cricket, distance running, American football, soccer, gymnastics, rugby, swimming, tennis. 24 Although most of these stress-related conditions resolved without growth complication during short-term follow-up, there are several reports of stress-related premature partial or complete distal radius physeal closure of young gymnasts. 25–29 These data indicate that sport training, if of sufficient duration and intensity, may precipitate pathological changes of the growth plate and, in extreme cases, produce growth disturbance. 24 , 32

Disturbed physeal growth as a result of injury can result in length discrepancy, angular deformity or altered joint mechanics and may cause significant long-term disability. 33 However, the incidence of long-term health outcome of physeal injuries in children's and youth sports is largely unknown.

Based on the previously selection criteria, 20 studies 54–73 were retained for analysis (Table  1 ). Injury to the physis can result in limb deformities and leg-length discrepancy, the latter being more common after motor vehicle accidents, rather than sports participation.

Evidence on acute physeal injury with subsequent adverse affects on growth.

OA in former athletes

Two studies investigated former top-level female gymnasts for residual symptoms (back pain) and radiographical changes. 74 , 75 Both studies reported no significant differences in back pain between gymnast and control groups; however, the prevalence of radiographical abnormalities was greater in gymnasts than controls in one study. 74

Lower limb weight-bearing joints such as the hip and the knee are at risk of developing OA after injury or in the presence of malalignment, especially in association with high impact sport. 76 Varus alignment was present in 65 knees (81%) in 81 former professional footballers (age 44–70 years), whereas radiographic OA in 45 (56%). 77 Others showed that prevalence of knee OA in soccer players and weight lifters was 26% (eight athletes) and 31% (nine athletes), respectively, whereas it was only 14% in runners (four athletes). 78 By stepwise logistic regression analysis, the increased risk is explained by knee injuries in soccer players and by high body mass in weight lifters. A survey in English former professional soccer players revealed that 47% retired because of an injury. The knee was most commonly involved (46%), followed by the ankle (21%). Of all respondents, 32% had OA in at least one lower limb joint and 80% reported joint pain. 79 Another study examined the incidence of knee and ankle arthritis in injured and uninjured elite football players. The mean time from injury was 25 years. 80 Arthritis was present in 63% of the injured knees and in 33% of the injured ankles, whereas the incidence of arthritis in uninjured players was 26% in the knee and 18% in the ankle. Obviously, it should be kept in mind that radiographic studies can only ascertain the presence of degenerative joint disease, which is just one of the features of OA. Clinical examination is always necessary to clarify the diagnosis, and formulate a management plan.

Ex-footballers also had high prevalence of hip OA (odds ratio: 10.2), 81 whereas in another study the incidence of hip arthritis was 5.6% among former soccer players (mean age: 55 years) compared with 2.8% in an age-matched control group. In 71 elite players it was higher (14%). Female ex-elite athletes (runners, tennis players) were compared with an age-matched population of women, and were found to have higher rates (2–3 fold increase) of radiographic OA (particularly the presence of osteophytes) of the hip and knee. 82 The risk was similar in ex-elite athletes and in a subgroup from the general population who reported long-term sports activity, suggesting that duration rather than frequency of training is important. An older study 83 is runners associated degenerative changes with genu varum and history of injury. A cohort of 27 Swiss long-distance runners was at increased risk of developing ankle arthritis compared with a control group. 84 Similarly elite tennis players were at risk of developing glenohumeral OA, 85 whereas handball players of developing premature hip OA, 86 and former elite volleyball players had marginally increased risk for ankle OA. 87 Interestingly a study that investigated the health-related quality of life (HRQL) in 284 former professional players in the UK found that medical treatment for football-related injuries was a common feature, as was arthritis, with the knee being most commonly affected. Respondents with arthritis reported poorer outcomes in all aspects of HRQL. 88

In summary, OA is more common among former athletes, compared with the general population. The lower limb joints are commonly affected, in association with high impact and injury.

Evidence from follow-up studies on spine of former athletes

Heavy physical work and activity lead to degenerative changes in the spine. Studies on different athletic disciplines and heavy workers have given variable degenerative changes and abnormalities in the lumbar spine. Even though sporting activity is regarded as an important predisposing factor in the development of spinal pathologies, 89–99 there are few studies on the late spinal sequelae of competitive youth sport. Any comparison in terms of back pain between top athletes and the general population is difficult. Experience of pain may be influenced by factors such as susceptibility, motivation and physical activity. Minor pain may be provoked by vigorous body movements that hamper athletic performance, thereby ascribing the pain a greater impact than in the general population. On the other hand, a well-motivated athlete may ignore even severe pain to maintain or improve his/her athletic performance. Also, varying rate/prevalence of osteophytosis has been reported in players associated with various disciplines of sports.

Efforts should be made to understand the aetiology of injuries to the intervertebral discs during athletic performance and thereby prevent them. 74

Based on the previously selection criteria, seven studies 74 , 89 , 98 , 100–103 were retained for analysis (Table  2 ). In summary, spine pathologies are associated more commonly with certain sports (e.g. wresting, heavy-weight lifting, gymnastics, tennis, soccer). Degenerative changes in the athlete's spine can occur, but they are not necessarily associated with clinically relevant symptoms of OA. Therefore, it cannot be determined whether it threatens the athlete's career, or whether it has a worse impact on athletes compared with the general population.

Evidence from follow-up studies on spine of former athletes.

Knee injury and OA in athletes

A population-based case-control study investigated the risk of knee OA with respect to sports activity and previous knee injuries of 825 athletes competing in different sports. They were matched with 825 controls. After confounding factors were adjusted, the sports-related increase risk of OA was explained by knee injuries. 104 Another study leads to the same conclusion: 23 American football high-school players were compared with 11 age-matched controls, 20 years after high-school competition. No significant increase in OA could be demonstrated clinically or radiographically. However, a significant increase in knee joint OA was found in the subgroup of football players who had sustained a knee injury. 105

A cohort of 286 former soccer players (71 elite, 215 non-elite) with a mean age of 55 years was compared with 572 age-matched controls, regarding the prevalence of radiographic features of knee arthritis. Arthritis in elite players, non-elite players and controls was 15%, 4.2% and 1.6%, respectively. In non-elite players, absence of history of knee injury was associated with arthritis prevalence similar to the controls. 106

An interesting study involved a cohort of 19 high-level athletes of the Olympic program of former East Germany. They sustained an ACL tear between 1963 and 1965. None were reconstructed, and all were able to return to sports within 14 weeks. Subsequent meniscectomies were necessary in 15/19 (79%) athletes at 10 years and 18/19 (95%) at 20 years, when in 18 of the 19 knees, arthroscopy was performed, 13 patients (68%) had a grade four chondral lesion. By year 2000 (more than 35 years after ACL rupture), 10/19 knees required a joint replacement. 107

The incidence of radiographic advanced degeneration (Kellgren–Lawrence grade 2 or higher) was 41% in a cohort of 122 Swedish male soccer players (from a total of 154) who consented to radiographic follow-up, 14 years after an ACL rupture. No difference was found between players treated with or without surgery for their ACL rupture. The prevalence of Kellgren–Lawrence grade 2 or higher knee OA was 4% in the uninjured knees. 108

Similar results were evident among Swedish female soccer players who were injured before the age of 20. The prevalence of radiographic OA was 51%, compared with 8% only in the uninjured knee, 12 years later. The presence of symptoms was documented in 63 of 84 (75%) athletes who answered the questionnaire, and was similar ( P = 0.2) in the two management groups (operative versus non-operative). The presence of symptoms did not necessarily correlate with radiographic OA ( P = 0.4). 109

In summary, knee injury is a recognized risk factor for OA. Injured athletes develop OA more commonly than the general population in the long term. Approximately half of the injured knees could have radiographic changes 10–15 years later. It is not clear whether radiographic changes correspond to presence of symptoms.

Ankle ligament injuries and OA in athletes

Ankle sprains are common sporting injuries generally believed to be benign and self-limiting. However, some studies report a significant proportion of patients with ankle sprains having persistent symptoms for months or even years. Nineteen patients with a mean age of 20 years (range: 13–28), who were referred to a sports medicine clinic after an ankle inversion injury, were followed for 29 months (average), and compared with matched controls. Only five (26%) injured patients had recovered fully, whereas 74% had symptoms 1.5–4 years after the injury. Assessments of quality of life using the short form-36 questionnaires revealed a difference in the general health subscale between the two groups, favouring the controls ( P < 0.05). 110

Similar conclusions were drawn from another study, regarding ankle injuries in a young (age range: 17–24 years) athletic population. 111 There were 104 ankle injuries (96 sprains, 7 fractures and 1 contusion), accounting for 23% of all injuries seen. Of the 96 sprains, 4 were predominately medial injuries, 76 lateral and 16 syndesmosis sprains. Although 95% had returned to sports at 6 weeks, 55% reported pain or loss of function. At 6 months, 40% had not fully recovered, reporting residual symptoms. Syndesmosis injuries were associated with prolonged recovery.

The association between ligamentous ankle injuries has been highlighted in a study that, retrospectively, reviewed data from 30 patients (mean age: 59 years, 33 ankles) with ankle osteoarthritis. 112 They found that 55% had a history of sports injuries (33% from soccer), and 85% had a lateral ankle ligament injury. The mean latency time between injury and OA was 34.3 years. The latency period for acute severe injuries was significantly lower (25.7 years), compared with chronic instability (38 years). Varus malalignment and persistent instability were present in 52% of those patients.

In summary, ankle ligamentous injuries in athletes can result in considerable morbidity, residual symptoms and arthritis 25–30 years later.

Shoulder injuries account for 7% of sports injuries and often limit the athlete in his or her ability to continue with their chosen sport. 113 Repetitive overhead throwing imparts high valgus and extension loads to the athlete's shoulder and elbow, often leading to either acute or chronic injury or progressive structural change and long-term problems in the overhead athlete. 45

Schmitt et al . 102 examined 21 elite javelin throwing athletes at an average of 19 years after the end of their high-performance phase (mean age at follow-up was 50 years). Five athletes (24%) complained about transient shoulder pain and three (16%) about elbow pain in their throwing arm affecting activities of daily living. All dominant elbows had advanced degeneration (osteophytes).

Elbow intra-articular lesions are recognized as consequences of repetitive stress and overuse. Shanmugam and Maffulli 9 reported follow-up (mean 3.6 years) of lesions of the articular surface of the elbow joint in a group of 12 gymnasts (six females and six males). This group showed a high frequency of osteochondritic lesions, intra-articular loose bodies and precocious signs of joint ageing. Residual mild pain in the elbow at full extension occurring after activity was present in 10 patients and all patients showed marked loss of elbow extension compared with their first visit.

Glenoid labral tears require repair, and shoulder instability is currently approached operatively more often. A review article found that conservative management of traumatic shoulder dislocations in adolescents was associated with high rates of recurrent instability (up to 100%). Therefore, surgical shoulder stabilization is recommended. The outcomes of surgical management are presented in the next section.

A distinct clinical entity is the ‘little league shoulder’, which is characterized by progressive upper arm pain with throwing and is more commonly seen in male baseball pitchers between ages 11 and 14 years. It is thought to be Salter-Harris type I stress fracture. Activity modification, education to improve throwing mechanics and core muscle training are recommended. It is not known how this condition behaves in the long term, regarding structural damage and development of degenerative changes.

Overhead athletes are plagued by shoulder and elbow injuries or overuse syndromes that can affect their performance and cause degeneration and pain in the long term.

The association between knee OA and meniscectomy has been well documented. In former athletes 114 – 116 it is associated with OA (Table  3 ). Meniscectomy in children and adolescents 117 – 123 has been associated with unfavourable results and radiographic arthritic changes in the long term (Table  4 ). However, radiographic criteria were not always clearly defined. To assess the long-term outcomes of meniscectomy, we also evaluated studies with a minimum follow-up of 10 years in the adult general population 106 , 124 – 129 (Table  5 ). Many of the ‘older’ studies providing the long-term outcomes represent results of open total meniscectomies. The overall message is that radiographic degeneration is common in meniscectomized knees, and patients are at risk of developing OA. The condition of the articular cartilage is a prognostic factor. However, clinical and radiographic findings do not always correlate. Resection should be limited to the torn part of the meniscus.

Menicectomy and osteoarthritis in athletes.

Menicectomy in children and adolescents.

Meniscectomy in adults / general popaltion—long-term outcomes.

Given the long-term problems associated with meniscectomies, preservation of the substance of the meniscus after injury is currently advocated. Based on this concept, arthroscopic meniscal repair techniques have been developed. 125 In the general population, encouraging clinical results with failure rates of 27–30% at 6–7 years follow-up have been reported. 130–132 One study 133 evaluated 45 meniscal repairs in 42 elite athletes followed for an average of 8.5 years. In 83% of them an ACL reconstruction was performed as well. Return to their sport was possible in 81% at an average of 10 months after surgery. They identified 11 failures (24%), seven of which were associated with a new injury. The medial meniscus re-ruptured more frequently compared with the lateral (36.4 versus 5.6%, respectively).

Mintzer et al . 134 retrospectively reviewed the outcome of meniscal repair in 26 young athletes involved in several sports at an average follow-up of 5 years (range: 2–13.5). No failures were reported, with 85% of patients performing high level of sports activities.

In general, the results of meniscal repairs in the general population, as well as in athletes, are encouraging.

ACL reconstruction and OA

Knee injuries can result in ligament ruptures and/or meniscal tears and are recognized as a risk factor of OA. A systematic review on studies published until 2006 135 reported on the prognosis of conservatively managed ACL injuries showed that there was an average reduction of 21% at the level of activities (Tegner score evaluation). ACL reconstruction is therefore a procedure frequently performed in athletic individuals, as they desire to maintain a high level of activities. However, does ACL reconstruction affect the incidence of knee degeneration and symptoms in the long term? We identified three studies 108 , 109 , 136 comparing operative versus non-operative management of ACL ruptures specifically in athletes, in regard to OA.

Two studies from Sweden investigating the prevalence of OA after ACL rupture in male 108 and female 109 soccer players were discussed earlier. Both found no difference in the incidence of radiographic arthritis between surgically and conservatively treated players, more than 10 years after their injury.

A comparative study 136 on high-level athletes with ACL injury showed no statistical difference between the patients treated conservatively or operatively (patella tendon graft) with respect to OA or meniscal lesions of the knee, as well as activity level, objective and subjective functional outcome. The patients who were treated operatively had a significantly better stability of the knee at examination.

Several studies present outcomes of ACL injuries in the general population. A recent systematic review included 31 studies (seven were prospective) reporting radiographic outcomes regarding OA, with more than 10 years follow-up after ACL injury. 137 The prevalence of OA in the injured knee varied from 1 to 100%, whereas in the contralateral knee it was 0–38%. Isolated ACL tears were associated with low OA incidence between 0 and 13%, whereas in the presence of additional meniscal injury, it was 21–48%. Meniscal injury and meniscectomy were the most frequently reported risk factors for OA. The authors scored the quality of the studies and found that studies scoring high reported low incidence of OA. Data extraction indicated that ACL reconstruction as a single factor did not prevent the development of knee OA. 137

There is lack of evidence to support a protective role of reconstructive surgery of the ACL against OA, both in athletes as well as in the general population.

ACL reconstruction in skeletally immature patients is a relatively new trend. 138 The concern is intra-operative epiphysis damage and growth disturbance, a complication which has been avoided in several studies. 139–143

The earliest published study 144 compared non-operative versus operative management of ACL ruptures in 42 skeletally immature athletes (age range: 4–17 years) followed for a mean of 5.3 years. They used a composite knee score based on clinical examination and a patient questionnaire and found superior results in the operatively treated patients. Age and growth plate maturity did not influence results. They recommended ACL reconstruction for active athletic children.

One of the early reports showed that there were no growth disturbances at a mean of 3.3 years after surgery in 9 children, however, with two re-ruptures. Those children could not return to athletic activities. 139

In a series of 57 ACL reconstructions, 15 patients had reached completion of growth when examined at follow-up, none had signs of growth disturbance, whereas clinical scoring was good or excellent in all patients. 142

Another study compared the outcomes of two management strategies in 56 children with ACL ruptures, namely ligament reconstruction in the presence of open physis, or delayed reconstruction after skeletal maturity. The ‘early’ reconstruction group had evidence of less medial meniscal tears (16 versus 41%), and no evidence of growth disturbances, at 27 months mean follow-up. 140

After 1.5–7.5 years follow-up of 19 ACL reconstructions in 20 athletic teenagers (age range: 11.8–15.6 years), all but one had returned to sports, none had tibiofemoral malalignment or a leg-length discrepancy of more than 1 cm, and the modified Lysholm score was 93 out of 95. 143

Finally, 55 children (ages 8 to 16 years, mean 13 years) were followed for a mean of 3.2 years (range: 1–7.5 years) after ACL reconstruction, with no evidence of growth disturbances. Clinical scores showed normal or almost normal values (higher than 90 out of 100 possible points) and 88% of the patients went back to normal or almost normal sports according to the Tegner score. 141

Overall, the clinical results are encouraging and iatrogenic epiphysis damage does not seem to be a problem, possibly because physeal sparing procedures were used. The study designs, however, are inadequate to answer the question of whether early or delayed ACL reconstruction results in the best possible outcome in skeletally immature patients.

Anterior impingement syndrome is a generally accepted diagnosis for a condition characterized by anterior ankle pain with limited and painful dorsiflexion. The cause can be either soft tissue or bony obstruction. Arthroscopic debridement is currently considered a routine procedure, and chondral lesions are now more frequently identified as causes of ankle pain. Few reports specifically in athletes are available 145–149 (Table  6 ). Short-term outcomes only are available. It is not known whether arthritis is a long-term consequence.

Ankle arthroscopy in athletes.

Only recently has the hip received attention as a recognized site of sports injuries, possibly as a result of the evolution of hip arthroscopy which allowed recognition of intra-articular pathology. 150 Acetabular labrum and chondral lesions can be addressed arthroscopically, and patients' satisfaction rates up to 75% have been reported. 44 One study evaluated the outcome of hip arthroscopy in 15 athletes (mean age: 32 years, range: 14–70) followed for 10 years. Nine were recreational athletes, four high school and two intercollegiate athletes. Diagnoses included cartilage lesion (8), labral tear (7), arthritis (5), avascular necrosis (1), loose body (1) and synovitis (1). The median improvement in the modified Harris hip score was 45 points (from 51 preoperatively to 96, on the 100-point scale), with 13 patients (87%) returning to their sport. All five athletes with arthritis eventually underwent total hip arthroplasty at an average of 6 years. 43 Long-term outcomes regarding progression of joint degeneration after traumatic chondral or labral damage are not available.

Operative management of shoulder injuries in athletes

Labral tears require repair, whereas shoulder instability is currently approached operatively more often. Conservative management of traumatic shoulder dislocations in adolescents is associated with high rates of recurrent instability (up to 100%), whereas recurrent dislocations were reported in up to 12%, at an average of 3 years after arthroscopic stabilization. Shoulder dislocations are particularly common in rugby, the characteristic mechanism of injury being tackling, whereas labral tears are common in the ‘overhead’ athlete'. Published results in athletes 151 – 162 (Table  7 ) show that operative stabilization of the shoulder is initially successful, but instability and pain can recur in the long term. Results of arthroscopic techniques in the management of intra-articular pathologies are promising, but long-term outcomes are unknown (Table  7 ).

RCT, randomized controlled trial; VAS, visual analogue scale.

Operative management of elbow injuries in athletes

Elbow ulnar collateral ligament (UCL) insufficiency is one of the frequently recognized injuries in the overhead athlete, as a result of excessive valgus stress. It constitutes a potentially career threatening injury and requires surgical repair. 163 The use of a muscle-splitting approach, avoiding handling of the ulnar nerve, and the use of the docking technique for stabilization is recommended 164 , 165 (Table  8 ). Recent advantages in arthroscopic surgical techniques and ligament reconstruction in the elbow have improved the prognosis for return to competition for highly motivated athletes. The results of arthroscopic debridement 150 , 166 (Table  7 ) need to be evaluated in the long term.

Operative management of elbow injuries in athletes.

UCL, ulnar collateral ligament.

Operative management of wrist injuries in athletes

A review of the literature shows that 3–9% of all athletic injuries occur in the hand or wrist, and are more common in adolescent athletes than adults. 46 In this article, we focused on TFCC injuries and acute scaphoid fractures in athletes.

TFCC injuries are an increasingly recognized cause of ulnar-sided wrist pain, and can be particularly disabling in the competitive athlete. Advances in wrist arthroscopy made endoscopic debridement and repair of the TFCC possible. McAdams et al . 47 treated arthroscopically TFCC tears in 16 competitive athletes (mean age: 23.4 years). Repair of unstable tears was performed in 11 (69%) and debridement only in 5 (31%). Return to play averaged 3.3 months (range: 3–7 months). The mean duration of follow-up was 2.8 years (range: 2–4.2 years). Clinical scores (mini-DASH and mini-DASH sports module) improved significantly. No long-term outcomes are available.

Operative management of scaphoid fractures in athletes, even if undisplaced, is recommended if early return to sports is desired. One study followed 12 athletes treated operatively for a scaphoid fracture. They were able to return to sports at 6 weeks. At an average follow-up of 2.9 years, 9 of 12 athletes had range of motion equal to the uninjured side, and grip strength was equal to the unaffected side in 10 of 12 athletes. 49

Participation in sports offers potential benefits for individuals of all ages, such as combating obesity and enhancing cardiovascular fitness. 1 On the other hand, negative consequences of musculoskeletal injuries sustained during sports may compromise function in later life, limiting the ability to experience pain-free mobility and engage in fitness-enhancing activity. 167 Increasingly, successful management of sports-related injuries has allowed more athletes to return to participation. The knee is the joint most commonly associated with sports injuries, and therefore is most at risk of developing degenerative changes. It is not clear whether radiographic OA always correlates with symptoms and reduced quality of life. Furthermore, even effective management of meniscal or ACL injury does not reduce the risk of developing subsequent OA. 137 , 168 OA in an injured joint is caused by intra-articular pathogenic processes initiated at the time of injury, combined with long-term changes in dynamic joint loading. Variation in outcomes involves not only the exact type of injury (e.g. ACL rupture with or without meniscal damage), 137 but also additional variables associated with the individual such as age, sex, genetics, obesity, muscle strength, activity and reinjury. A better understanding of these variables may improve future prevention and treatment strategies. 169

In many of the long-term studies (the majority being retrospective case series), several methodological flaws have to be highlighted. A recent systematic review on OA after ACL injuries 137 suggested that some studies may overestimate the prevalence of long-term OA. The authors in several studies mention that a proportion of the index group of injured athletes were available for follow-up or consented for radiographic examination. One can argue that these patients were the ones with symptoms, therefore the prevalence of OA (after ACL rupture for example) may appear higher than it really is. Presentation of outcomes was not always based on robust criteria. Different clinical scores and radiographic classifications have been used, and therefore results between studies are not directly comparable. In the majority of the studies, it was not clarified whether radiographic appearance correlated with symptoms, and how important these were for the quality of life of the patients. Disabling arthritis requiring intervention may actually be delayed for more than 20–30 years. 107 , 112 Furthermore, long-term studies present outcomes of older techniques, not used any more in clinical practice (e.g. primary ACL repair or total meniscectomy). Evolution in surgical or rehabilitation techniques might have improved outcomes of certain injuries. Therefore, currently known ‘long-term outcomes’ may only reflect the results of techniques used in the past and not what we should expect in the future. Increasing awareness of athletes and trainers, new diagnostic and musculoskeletal imaging modalities, improved surgical and rehabilitation methods, but also analysis of injury patterns in different sports and development of injury prevention strategies might be beneficial to minimize the effects of sports injuries in the years to come.

What is the true incidence of arthritis in the long term? Will it be a disabling condition for the former athlete, in the coming decades? Currently, joint preserving procedures (e.g. microfractures, 145 mosaicplaty, 170 autologous chondrocyte implantation, 171 , 172 realignment osteotomies 173 and implant arthroplasties 174 ) have evolved and allow middle aged or older patients to live without pain and maintain an active life style. Meniscal transplantation shows encouraging results. 175 Should therefore an increased risk for developing musculoskeletal problems prevent children and adults from being active in sports? 176 Do the benefits of participating in sports outweigh the risks?

A survey in Sweden showed that 80% of former track and field athletes with an age range of 50–80 years felt they were in good health, compared with 61% of the referents, despite higher prevalence of hip arthritis in former athletes. Low back disorders were similar in the two groups, shoulder and neck problems were lower in former athletes, and knee arthritis was similar in the two groups. 177

No definite answer can be given to the previously addressed questions, based on available evidence. Future research should involve questionnaires assessing the HRQL in former athletes, to be compared with the general population. 27 , 178–181

Physical injury is an inherent risk in sports participation and, to a certain extent, must be considered an inevitable cost of athletic training and competition. Injury may lead to incomplete recovery and residual symptoms, drop out from sports, and can cause joint degeneration in the long term. Few well-conducted studies are available on the long-term follow-up of former athletes, and, in general, we lack studies reporting on the HRQL to be compared with the general population. Advances in arthroscopic techniques allow operative management of most intra-articular post-traumatic pathologies in the lower and upper limb joints, but long-term outcomes are not available yet. It is important to balance the negative effects of sports injuries with the many social, psychological and health benefits that a serious commitment to sport brings. 9

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Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials

Increasing nitric oxide bioavailability may induce physiological effects that enhance endurance exercise performance. This review sought to evaluate the performance effects of consuming foods containing compou...

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Correction to: Supplement intake in half-marathon, (ultra-)marathon and 10-km runners – results from the NURMI study (Step 2)

The original article was published in Journal of the International Society of Sports Nutrition 2021 18 :64

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Effects of sodium bicarbonate supplementation on exercise performance: an umbrella review

We aimed to perform an umbrella review of meta-analyses examining the effects of sodium bicarbonate supplementation on exercise performance.

Association of energy availability with resting metabolic rates in competitive female teenage runners: a cross-sectional study

Resting metabolic rate (RMR) has been examined as a proxy for low energy availability (EA). Previous studies have been limited to adult athletes, despite the serious health consequences of low EA, particularly...

Effects of glucose ingestion at different frequencies on glycogen recovery in mice during the early hours post exercise

When a high-carbohydrate diet is ingested, whether as small frequent snacks or as large meals, there is no difference between the two with respect to post-exercise glycogen storage for a period of 24 h. Howeve...

Resting energy expenditure in elite athletes: development of new predictive equations based on anthropometric variables and bioelectrical impedance analysis derived phase angle

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Effects of chronic betaine supplementation on performance in professional young soccer players during a competitive season: a double blind, randomized, placebo-controlled trial

Various nutritional strategies are adopted for athletes to maintain and to improve performance during the competition season. Betaine may enhance performance during a competitive season by increasing the testo...

Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis

Previous narrative reviews have concluded that dietary nitrate (NO 3 − ) improves maximal neuromuscular power in humans. This conclusion, however, was based on a limited number of studies, and no attempt has been ma...

The effect of omega-3 fatty acids on a biomarker of head trauma in NCAA football athletes: a multi-site, non-randomized study

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Supplement intake in half-marathon, (ultra-)marathon and 10-km runners – results from the NURMI study (Step 2)

The primary nutritional challenge facing endurance runners is meeting the nutrient requirements necessary to optimize the performance and recovery of prolonged training sessions. Supplement intake is a commonl...

The Correction to this article has been published in Journal of the International Society of Sports Nutrition 2021 18 :75

Effects of carbohydrate and caffeine mouth rinsing on strength, muscular endurance and cognitive performance

Carbohydrate (CHO) and caffeine (CAF) mouth rinsing have been shown to enhance endurance and sprint performance. However, the effects of CHO and CAF mouth rinsing on muscular and cognitive performance in compa...

Effects of 30 days of ketogenic diet on body composition, muscle strength, muscle area, metabolism, and performance in semi-professional soccer players

A ketogenic diet (KD) is a nutritional approach, usually adopted for weight loss, that restricts daily carbohydrates under 30 g/day. KD showed contradictory results on sport performance, whilst no data are ava...

International Society of Sports Nutrition position stand: sodium bicarbonate and exercise performance

Based on a comprehensive review and critical analysis of the literature regarding the effects of sodium bicarbonate supplementation on exercise performance, conducted by experts in the field and selected membe...

The effects of phosphocreatine disodium salts plus blueberry extract supplementation on muscular strength, power, and endurance

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Prevalence, factors associated with use, and adverse effects of sport-related nutritional supplements (sport drinks, sport bars, sport gels): the US military dietary supplement use study

Sport-related nutritional supplements (SRNSs) include sport drinks, sport bars, and sport gels. Previous studies indicate that 25–35 % of athletes and 25–50 % of military personnel report using these supplemen...

Mitochondria-targeted antioxidant supplementation improves 8 km time trial performance in middle-aged trained male cyclists

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This paper aimed to verify how a supplementation of rower’s diet with Astragalus Membranaceus Root (AMR) modulated their immune system response to maximal physical exertion.

Initiating aerobic exercise with low glycogen content reduces markers of myogenesis but not mTORC1 signaling

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The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis

Nitrate supplementation is thought to improve performance in endurance sports.

Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study

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Temporal trends in dietary creatine intake from 1999 to 2018: an ecological study with 89,161 participants

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Flexible vs. rigid dieting in resistance-trained individuals seeking to optimize their physiques: A randomized controlled trial

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Chronic capsiate supplementation increases fat-free mass and upper body strength but not the inflammatory response to resistance exercise in young untrained men: a randomized, placebo-controlled and double-blind study

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Effects of acute ingestion of caffeinated chewing gum on performance in elite judo athletes

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The effect of multi-ingredient intra- versus extra-cellular buffering supplementation combined with branched-chain amino acids and creatine on exercise-induced ammonia blood concentration and aerobic capacity in taekwondo athletes

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Broad Spectrum Polyphenol Supplementation from Tart Cherry Extract on Markers of Recovery from Intense Resistance Exercise

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Elite squash players nutrition knowledge and influencing factors

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The role of age in the physiological adaptations and psychological responses in bikini-physique competitor contest preparation: a case series

The increased popularity of the bikini-physique competitions has not translated to greater research identifying the influence of age on adaptations during contest preparation. The purpose of this case series w...

Effects of antioxidant supplementation on oxidative stress balance in young footballers- a randomized double-blind trial

Intensive physical exercise that competitive sports athletes participate in can negatively affect their pro-oxidative–antioxidant balance. Compounds with high antioxidant potential, such as those present in ch...

Redox and autonomic responses to acute exercise-post recovery following Opuntia ficus-indica juice intake in physically active women

The aim of this study was to investigate if the supplementation with Opuntia ficus-indica (OFI) juice may affect plasma redox balance and heart rate variability (HRV) parameters following a maximal effort test, i...

Effects of 14-weeks betaine supplementation on pro-inflammatory cytokines and hematology status in professional youth soccer players during a competition season: a double blind, randomized, placebo-controlled trial

Systemic elevations in pro-inflammatory cytokines are a marker of non-functional over reaching, and betaine has been shown to reduce the secretion of pro-inflammatory cytokines in vitro. The aim of this study ...

Body composition changes in physically active individuals consuming ketogenic diets: a systematic review

To achieve ideal strength/power to mass ratio, athletes may attempt to lower body mass through reductions in fat mass (FM), while maintaining or increasing fat-free mass (FFM) by manipulating their training re...

Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament

Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare...

Taurine in sports and exercise

Taurine has become a popular supplement among athletes attempting to improve performance. While the effectiveness of taurine as an ergogenic aid remains controversial, this paper summarizes the current evidenc...

Metabolic, hormonal and performance effects of isomaltulose ingestion before prolonged aerobic exercise: a double-blind, randomised, cross-over trial

Isomaltulose has been discussed as a low glycaemic carbohydrate but evidence concerning performance benefits and physiological responses has produced varying results. Therefore, we primarily aimed to investiga...

Performance effects of periodized carbohydrate restriction in endurance trained athletes – a systematic review and meta-analysis

Endurance athletes typically consume carbohydrate-rich diets to allow for optimal performance during competitions and intense training. However, acute exercise studies have revealed that training or recovery w...

The effect of probiotic supplementation on performance, inflammatory markers and gastro‐intestinal symptoms in elite road cyclists

Elite athletes may suffer from impaired immune function and gastro-intestinal (GI) symptoms, which may affect their health and may impede their performance. These symptoms may be reduced by multi-strain probio...

A large-scale observational study linking various kinds of physical exercise to lipoprotein-lipid profile

Being a major cardiovascular risk factor, dyslipidemia is a critical problem in public health. Recommendations in performing regular physical exercise are important to prevent dyslipidemia.

Development and validation of a food frequency questionnaire for Japanese athletes (FFQJA)

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Change in eating habits and physical activities before and during the COVID-19 pandemic in Hong Kong: a cross‐sectional study via random telephone survey

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Correction to: Analysis of food and fluid intake in elite ultra-endurance runners during a 24-h world championship

An amendment to this paper has been published and can be accessed via the original article.

The original article was published in Journal of the International Society of Sports Nutrition 2020 17 :36

Correction to: Serum and urinary concentrations of arsenic, beryllium, cadmium and lead after an aerobic training period of six months in aerobic athletes and sedentary people

The original article was published in Journal of the International Society of Sports Nutrition 2020 17 :43

Correction to: Erythrocyte concentrations of chromium, copper, manganese, molybdenum, selenium and zinc in subjects with different physical training levels

The original article was published in Journal of the International Society of Sports Nutrition 2020 17 :35

Serum levels of bone formation and resorption markers in relation to vitamin D status in professional gymnastics and physically active men during upper and lower body high-intensity exercise

To compare serum levels of bone turnover markers in athletes and non-athletes, and to evaluate the relationship between serum levels of vitamin D metabolites and exercise-induced changes in biomarker levels.

Copper concentration in erythrocytes, platelets, plasma, serum and urine: influence of physical training

Physical training produces changes in the extracellular and intracellular concentrations of trace minerals elements. To our knowledge, only three compartments have been studied simultaneously. The aim of the p...

Sex differences and considerations for female specific nutritional strategies: a narrative review

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Journal of the International Society of Sports Nutrition

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Teams planning management changes on "Black Monday" can learn much from academic research on National Football League coaches, say Boris Groysberg and Abhijit Naik. The findings hold value not only for football teams, but for any organization that depends on leadership for success. Open for comment; 0 Comments.

• 26 Oct 2015

What’s the Value of a Win in College Athletics?

As debate continues over whether student-athletes should be paid, professor Doug Chung’s research on the massive money being earned by collegiate football and basketball programs could help guide the answer. Open for comment; 0 Comments.

• 06 Mar 2006

Winners and Losers at the Olympics

We know which athletes won and lost in Turin, but what about the companies and individuals looking for business gold? Professor Stephen A. Greyser looks at the results—and the possibilities ahead in China. Closed for comment; 0 Comments.

ORIGINAL RESEARCH article

Is passion contagious in coach-athlete dyads a dyadic exploration of the association between passion, affective and need-based experiences in individual sports.

• Ghent University, Ghent, East Flanders, Belgium

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The Dualistic Model of Passion distinguishes between harmonious and obsessive passion, which are associated with athletes' and coaches' adjustments. Whereas prior research sampled either athletes or coaches, the present study used a dyadic approach to explore the bidirectional influence of passion on affective experiences in coaches and athletes. Using a cross-sectional dyadic design, 198 coachathlete dyads involved in an individual sport at different competition levels, reported on their passion, need-based, and affective experiences. Both actor effects (i.e., intrapersonal dynamics within athletes or coaches) and partner effects (i.e., interpersonal dynamics from coach to athlete and vice versa) were examined. Furthermore, dyadic mediation models were used to investigate the potential mediating role of need-based experiences in the association between passion and affective experiences. Results unveiled compelling evidence for actor effects, indicating that one's own harmonious passion was positively related to one's own more adaptive outcomes and negatively to one's own more maladaptive outcomes, whereas obsessive passion was positively related to maladaptive outcomes. Further, very limited evidence for partner effects, in which coaches' passion affected athletes' outcomes or vice versa, was found. The dyadic mediation models underscored the role of need-based experiences in mediating the association between passion and affective experiences, but only at the intrapersonal level. As such, one's own passion experiences were related to one's own need-based experiences, which in turn were related to one's own affective experiences. The study provided no evidence for interpersonal mediation effects.

Keywords: passion, need satisfaction, positive affect, Actor-partner interdependence model, bidirectional influence. (Min

Received: 11 Jan 2024; Accepted: 10 Apr 2024.

Copyright: © 2024 Fonteyn, Haerens, Vansteenkiste and Loeys. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Tom Loeys, Ghent University, Ghent, 9000, East Flanders, Belgium

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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Grubbs JB , Kraus SW. Binge Drinking Among Sports Gamblers. JAMA Netw Open. 2024;7(4):e245473. doi:10.1001/jamanetworkopen.2024.5473

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Binge Drinking Among Sports Gamblers

• 1 Department of Psychology, Center on Alcohol, Substance use, And Addictions, University of New Mexico, Albuquerque
• 2 Department of Psychology, University of Nevada, Las Vegas

Over the past 6 years, sports wagering has become accessible to most individuals in the US via mobile applications or websites. 1 Increasing evidence suggests that sports wagering is associated with greater substance use and misuse, particularly alcohol, and symptoms of alcohol use disorder. 2 - 4 Alcohol consumption is higher among sports gamblers, 3 and sports gamblers often use substances while gambling. 5 Sports gamblers tend to be more inclined toward risk taking, suggesting that sports gambling may be associated with more risky alcohol use behaviors. 4 - 6 Accordingly, we examined whether individuals who wager on sports in the US are at greater risk of binge use of alcohol.

This survey study was approved by the Bowling Green State University Institutional Review Board; informed consent was obtained from all participants. The study followed the AAPOR reporting guideline.

From March 17 to April 6, 2022, we collected a census-matched sample of US adults with an oversample of adults who wager on sports. Full information about this survey is available elsewhere. 1 Race and ethnicity data were collected because they are potential factors in sports gambling likelihood and binge drinking habits. Among those reporting any past year alcohol use, binge drinking was assessed via the National Institute on Drug Abuse Quick Screen, version 1.0, which asks how often respondents consumed an excess of alcohol at a single time (≥5 drinks for men; ≥4 for women). Participants responded on a scale of 1 (never) to 5 (daily or more). Sports betting status was assessed by asking participants whether they had placed bets on sporting events or esports or participated in daily fantasy sports over the past 12 months.

Statistical analyses were conducted in SPSS, version 28. We conducted 2-tailed χ 2 analyses for distributions of past year binge drinking frequency, followed by multinomial logistic regressions estimating binge drinking frequency; P  < .05 was considered statistically significant.

A total of 4363 respondents were included (51.4% men, 46.4% women, and 2.2% nonbinary or other; mean [SD] age, 49.6 [16.2] years) ( Table 1 ). The national census-matched survey consisted of 2806 participants (mean [SD] age, 48.9 [17.2] years; 1365 [48.6%] men and 1441 [51.4%] women; response rate, 2806 of 3203 [87.6%]). The oversample of sports gamblers consisted of 1557 participants (mean [SD] age, 41.7 [15.3] years; 1043 [67.0%] men and 514 [33.0%] women; response rate, 1557 of 1978 [78.7%]), of whom 1474 reported past year sports betting. Additionally, in the national sample, 338 respondents (12.0%) indicated they had gambled on sports in the past 12 months, resulting in a total of 1812 sports gamblers ( Table 1 ). Sports gamblers were disproportionally likely to be men and younger. In these combined samples, 3267 respondents (74.9%) reported past year alcohol use.

Sports wagerers were disproportionately more likely to report binge drinking at monthly or greater frequency over the past 12 months and were also disproportionately less likely to report no binge drinking episodes in the past 12 months ( Table 1 ). Multinomial logistic regressions adjusted for age and race and ethnicity showed that sports gamblers were substantially more likely to report higher levels of binge drinking ( Table 2 ), suggesting that elevated risky drinking episodes among sports gamblers are not due to demographic differences.

In this survey study, binge drinking in both men and women was reported at greater frequency among sports wagering individuals compared with nongamblers and non–sports gamblers. This study is limited by its cross-sectional design and use of nonprobability polling methods. Regardless, with past research showing that sports gamblers are more likely to report symptoms of alcohol use disorder, our results suggest that individuals who wager on sports use alcohol in particularly risky ways. Given the rapid spread of sports wagering in the US over recent years, this finding highlights an immense need for ongoing research, particularly to examine how novel gambling technologies influence the prevalence, presentation, and prevention of alcohol use disorders and related harms.

Accepted for Publication: February 9, 2024.

Published: April 1, 2024. doi:10.1001/jamanetworkopen.2024.5473

Open Access: This is an open access article distributed under the terms of the CC-BY License . © 2024 Grubbs JB et al. JAMA Network Open .

Corresponding Author: Joshua B. Grubbs, PhD, Center for Alcohol, Substance Use, and Addiction, University of New Mexico, 2650 Yale Blvd SE, Albuquerque, NM 87106 ( [email protected] ).

Author Contributions: Drs Grubbs and Kraus had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Both authors.

Acquisition, analysis, or interpretation of data: Both authors.

Drafting of the manuscript: Both authors.

Critical review of the manuscript for important intellectual content: Both authors.

Statistical analysis: Both authors.

Obtained funding: Both authors.

Administrative, technical, or material support: Grubbs.

Conflict of Interest Disclosures: Dr Grubbs reported receiving research grant funding from the Problem Gambling Network of Ohio outside the submitted work. Dr Kraus reported receiving personal fees from New York Council on Problem Gambling, the International Center for Responsible Gaming, the California Council on Problem Gambling, and Massachusetts General Hospital Psychiatry Academy, serving as editor-in-chief for Taylor & Francis journals, and receiving Summer research support from the Nevada Project on Problem Gambling during the conduct of the study. No other disclosures were reported.

Funding/Support: This study was supported by grants from the International Center for Responsible Gaming, the Kindbridge Research Institute, and the Problem Gambling Network of Ohio.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Data Sharing Statement: See the Supplement .

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36 disciplines in the global top 50 in QS Subject Rankings

The University of Sydney has performed strongly in the 2024 QS World University Rankings by Subject, with six disciplines ranked in the global top 20 and 36 in the top 50.

The rankings also put the University first in Australia in ten disciplines and overall 28 subjects improved their global ranking.

The annual QS subject rankings cover 55 disciplines within five broad subject areas: Arts and Humanities; Engineering and Technology; Life Sciences and Medicine; Natural Sciences; and Social Sciences and Management. 

The University succeeded in having two disciplines in the top ten globally, adding Anatomy and Physiology, which moved from 13th to sixth in the world, to Sports-related subjects, which remained at fourth. Joining them in the top 20 worldwide are Nursing (equal 14th), Law and Legal Studies (16th), English Language and Literature (equal 19th) and Pharmacy and Pharmacology (20th).

Domestically, the University ranked first in Australia for ten disciplines - Anatomy and Physiology, Classics and Ancient History, Computer Science and Information Systems, Statistics and Operational Research, English Language and Literature, Library and Information Management, History of Art, Performing Arts, Nursing and Veterinary Science.

The QS subject rankings include measures of academic and employer reputation and research excellence, including citations. 

“While rankings are only one of many ways of measuring a university’s performance our continuing success in these and other major rankings demonstrate the quality of our teaching and research staff, to the benefit of our students and of society,” said Vice-Chancellor and President, Professor Mark Scott.  

“We’ve also delivered on our commitment to research and teaching excellence with the appointment this year of 40 Sydney Horizon Fellowships for early and mid-career researchers and under the Sydney Horizon Educators scheme, the University will advertise 220 new education-focused positions by 2026.”

The most recent research successes from the University include:

• researchers in robotics developing a new approach to designing cameras , which could help protect the images and data collected by smart home devices and internet-of-things technology
• social policy researchers revealing the lack of cost-saving innovations in aged care is due to chronic underinvestment in research and development
• collaboration on research showing that the asteroid that wiped out the dinosaurs was a 'big bang' for bird evolution
• Social Justice Practitioners-in-Residence finding that overuse of non-disclosure agreements disadvantages and discriminates against women
• musculoskeletal health researchers challenging the common belief that there is a clear connection between the weather and back, knee or hip pain
• a new process to helping shed light on how to better prevent embrittlement, one of the biggest obstacles facing the transition to a global hydrogen economy.

“The range and depth of disciplines in which we continue to both excel and to improve our performance is testament to our research excellence and the potential for it to be translated into real-world impact whether via technology, policy, treatment, education, the arts or by becoming the evidence-based foundation for other discoveries,” said University of Sydney Deputy Vice-Chancellor (Research) Professor Emma Johnston.  

Adding to the University’s achievement was an improvement in four disciplines, moving them into the top 50 internationally: Computer Science and Information Systems (43rd), Dentistry (48th), Engineering – Electrical and Electronic (equal 49th), Theology, Divinity and Religious Studies (38th). 

The 36 disciplines in the top 50 worldwide included four disciplines which only began being ranked this year: Data Science and Artificial Intelligence (43rd), Engineering – Mineral and Mining (equal 25th), History of Art (21-40th) and Marketing (21-50th), noting specific ranks are only applied to the top 25 percent of each subject’s ranking. 

The University ranked equal 19th globally in the highly regarded 2024 QS World University Rankings, published in 2023. 

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