AOSSM Early Sport Specialization Consensus Statement.

BACKGROUND: Early sport specialization is not a requirement for success at the highest levels of competition and is believed to be unhealthy physically and mentally for young athletes. It also discourages unstructured free play, which has many benefits.
PURPOSE: To review the available evidence on early sports specialization and identify areas where scientific data are lacking. STUDY
DESIGN: Think tank, roundtable discussion.
RESULTS: The primary outcome of this think tank was that there is no evidence that young children will benefit from early sport specialization in the majority of sports. They are subject to overuse injury and burnout from concentrated activity. Early multisport participation will not deter young athletes from long-term competitive athletic success.
CONCLUSION: Youth advocates, parents, clinicians, and coaches need to work together with the sport governing bodies to ensure healthy environments for play and competition that do not create long-term health issues yet support athletic competition at the highest level desired.

Despite mounting scientific evidence and professional athletes speaking out against its value, the trend of early sports specialization continues with tournaments and competitive leagues increasingly available as well as wider media exposure (eg, The Short Game [7- to 8-year-old golfers], Friday Night Tykes [Texas Youth Football]). Early sports specialization, or early single-sport specialization, is believed to be potentially damaging to the long-term physical and mental health of athletes and has not been validated as a requirement for competitive success in sport.[3] Early youth sport specialization has been associated with increased rates of overuse injury, burnout, decreased motivation for participation, and sports withdrawal,[19,33,34,43] while multisport participation is proposed to result in better long-term performance and an increase in lifetime enjoyment of physical activity and recreational sports participation.[2]

With these issues in mind, the American Orthopaedic Society for Sports Medicine (AOSSM) convened a think tank on the topic of early sports specialization on October 2, 2015, in Rosemont, Illinois. This report represents the consensus of the participants of this meeting; importantly, it identifies areas where more research is necessary to address the outstanding questions surrounding this topic (Appendix 1) and achieve the goal of healthy athletic participation through adulthood at the highest level of participation desired.

Definition of Early Sports Specialization and Background Information

It was the consensus at this symposium that early sports specialization, or early single-sport specialization, be defined by the following 3 criteria:

Participation in intensive training and/or competition in organized sports greater than 8 months per year (essentially year round)[34]

Participation in 1 sport to the exclusion of participation in other sports (limited free play overall)[33]

Involving prepubertal (seventh grade or roughly age 12 years) children.

What is the Evidence That Early Sports Specialization is Detrimental?

A variety of researchers and organizations have investigated the impact of early sports specialization on long-term health and future sport success. The consensus statement of the American Medical Society for Sports Medicine[19] on overuse injuries and burnout in youth sports contends that a variety of physical and mental health concerns can be attributed to early sports specialization. In their position statement, they identify the concerns listed in Table 1.

Table 1

Categorization of Risk Factors for Overuse Injury

Growth-related factors

Susceptibility of growth cartilage to repetitive stress

Adolescent growth spurt

Other intrinsic factors

Previous injury

Previous level of conditioning

Anatomic factors

Menstrual dysfunction

Psychological and developmental factors (athlete-specific)

Extrinsic factors

Training progression

Equipment/footwear

Sport technique

Psychologic factors (adult and peer influences)

Adapted from DiFiori et al.[19] Reprinted with permission.

Their recommendations for avoiding burnout and injury include the following:

Avoiding overscheduling and excessive time commitments

Consider using a valid and reliable tool to monitor burnout

Emphasize skill development and fun

Emphasize lifelong physical activity skills.

The International Olympic Committee[8] also published a consensus statement on youth athletic development. Their goal was to develop healthy, capable, and resilient young athletes while attaining widespread inclusive, sustainable, and enjoyable participation and success for all levels of athletic achievement. They identified several physical and mental health concerns associated with youth athletic talent development, including insufficient sleep, increased overuse injury rates, overtraining, burnout, and eating disorders. They recommended that children be encouraged to participate in a variety of different activities and develop a wide range of skills and avoid specialization until at least puberty. They recommended focusing on the integration of strength and neuromuscular fitness in conjunction with the development of the entire athlete in terms of competence, confidence, connection, and character.

Researchers have suggested that early specialization isolates the young athlete from their peers (interferes with normal identity development) and increases the potential for burnout or withdrawal from sport as a result of chronic stress.[11,43] Athletes who experience burnout are characterized by a loss of motivation and especially have decreased intrinsic motivation, a lack of enjoyment, high perceived stress and anxiety, ineffective or limited stress coping strategies, and mood disturbances.[23,24]

Several types of burnout have been identified.[25,26] One of these is social psychological in nature and is driven by factors such as perfectionism in the young athlete or excessive coach and/or parental pressure to perform. The other type is driven by physical factors, such as overtraining and lack of sleep. Research suggests, then, that while high training loads are certainly involved in athlete burnout, other personal and situational factors of a social psychological nature also play a very important role.[20,25,26] Recent evidence also suggests that monitoring the balance between intensive sports participation/specialization and other childhood commitments such as friends, school, and extracurricular activities is important to consider in determining the health and wellness status of young athletes.[20]

Studies directly linking youth sports specialization to psychosocial outcomes are lacking. However, the available evidence suggests youth specialization before the age of 12 years is associated with increased burnout and dropout rates and decreased athletic development over time.[22] Importantly, there is a lack of evidence that early specialization is necessary for adult elite performance. In a German study, 88% of Olympians reported participating in more than 1 sport as a child.[28] Work by Güllich and Emrich[27] evaluated 1558 German national squad athletes in Olympic sports and reported that a great training volume in other sports beyond the individual’s current main sport was associated with great long-term success in an elite sport (unpublished data, 2006). In addition, 97% of professional athletes believed being a multisport athlete was beneficial to their success in another study.[39]

One factor driving the emphasis on early specialization is the increasingly common practice of early talent identification/selection. Researchers in this area note that talent identification is difficult at all phases of development, but particularly difficult to identify before puberty. The available evidence reviewed at this meeting does not support the belief that early sports specialization is a requirement (gymnastics and figure skating may be examples of exceptions because the top tiers of competition tend to occur during the teenage years to the early 20s). Diversification of sports during childhood results in increased long-term participation, increased adult performance, and increased personal development.[17] Moreover, early diversification does not seem to hinder elite-level participation in sports where peak performance occurs after maturation.[4] A transition period seems to occur around the end of primary school (at age approximately 13 years). Playing sport without the consistent intervention of coaches (youth-led activities like play) has also been identified as necessary to develop good skill levels prior to this age.

Is Early Specialization Necessary for Elite Performance?

Support for early specialization comes from the assumption that early training experiences distinguish those who become experts/elites from those who do not. Much of the recent rhetoric regarding early sports specialization can be traced to studies of “deliberate practice,” a specific form of training proposed by Ericsson and colleagues[21] more than 2 decades ago. Deliberate practice is highly effortful and relevant to performance improvement, and Ericsson et al[21] proposed that anyone beginning deliberate practice early would have a benefit over peers starting later. Despite the consistent evidence for the value of deliberate practice for athlete development in general,[6] there is very little support for the necessity of high amount of deliberate practice during childhood for the development of adults’ elite performance. Comparisons of experts and nonexperts in field hockey,[29] soccer,[29] and triathlon[5] found that differences in training profiles did not occur until age 13, 15, and 20 years, respectively. Although there may be specific sports where early specialization is required due to early ages of peak performance (eg, gymnastics, figure skating, diving), the overall evidence supporting early specialization, as a general requirement for elite performance in sport where peak performance is achieved in adulthood, is not convincing. It is felt that some, but not all, athletes in early entry sports such as women’s gymnastics, figure skating, and dance may benefit from specialization because their peak competitive levels generally occur before full maturity. These sports may lend themselves to be at the forefront of the effort to reset competitive expectations so that early specialization would not be necessary to meet the expectations of the sport.

What Research has Been Done to Date?

Several models of athlete development in sport have been proposed in the literature to explain long-term participation and performance in sport.[1,12,41,44] Systematic review studies of athletes’ development models[9,10] have reported that the Developmental Model of Sport Participation (DMSP)[12,14] is the most prominent conceptualization of athletes’ development within the sports literature. The DMSP is a conceptual framework that integrates the developing athlete in its environment with processes that focus on early diversification and play.

The different stages of the DMSP are based on changes in the type and amount of involvement in different sports, deliberate play, and deliberate practice throughout an athlete’s career.[16] It is composed of a series of 7 postulates associated with the different pathways and outcomes of the DMSP. The postulates highlight the efficiency of sport programs to develop adult elite performance, continued participation, and personal development based on early sampling (postulates 1, 2, and 3), deliberate play (postulates 4 and 5), and key transitions throughout development (postulates 6 and 7). The DMSP and its postulates (Table 2) integrate the various outcomes of sport—performance, participation, and personal development—by focusing on key proximal processes (deliberate play, deliberate practice, and early sampling) and the environment in which the processes are occurring (role of coaches, peers, and parents).

Table 2

Seven Postulates Associated With the Different Pathways of the Development Model of Sport Participation

Postulate 1: Early diversification does not hinder elite sport participation in sports where peak performance is reached after maturation.

Postulate 2: Early diversification is linked to a longer sport career and has positive implications for long-term sport involvement.

Postulate 3: Early diversification allows participation in a range of contexts that most favorably affects positive youth development.

Postulate 4: High amounts of deliberate play during the sampling years build a solid foundation of intrinsic motivation through involvement in activities that are enjoyable and promote intrinsic regulation.

Postulate 5: A high amount of deliberate play during the sampling years establishes a range of motor and cognitive experiences that children can ultimately bring to their principal sport of interest.

Postulate 6: Around the end of primary school (about age 13 years), children should have the opportunity to choose to either specialize in their favorite sport or continue in sport at a recreational level.

Postulate 7: Late adolescents (around age 16 years) have developed the physical, cognitive, social, emotional, and motor skills needed to invest their effort into highly specialized training in one sport.

Adapted from Côté et al.[16] Reprinted with permission.

A review of the evidence that supports these postulates can be found in recent publications.[13,17] In sum, the DMSP and its 7 postulates are based on a developmental approach that features the interaction of variables at the activity (eg, deliberate play, diversification) and the environment levels (eg, sport setting, coaching) that have strong implications for youth sport policies.[15]

The current evidence supports the contention that children should be encouraged to take part in a variety of sports at levels consistent with their abilities and interests to best attain the physical, psychological, and social benefits of sport.[36] Children who specialize early (eg, prior to maturation) in a single sport may execute less age-appropriate sports skills, especially when they do not participate in as many youth-led activities (eg, deliberate play) as their peers. Without opportunities to experience sport diversification, children may not fully develop neuromuscular patterns that may be protective of injury. Based on the cumulative evidence, sport specialization was concluded to be a real issue that will very likely continue to occur in many sports. The authors recommend the inclusion of diverse opportunities for motor skill development during the growing years, combined with planned integrative neuromuscular training to help optimize the potential for success and reduced injury risk in young athletes (Figure 1).[37]

Figure 1.

Qualified education and instruction support the complex programming components for effective implementation of integrative neuromuscular training. Reprinted with permission from Myer et al.[35]

It is well accepted that youth-driven play has shifted greatly toward parent- and coach-driven activities recently at the expense of free play (N. Jayanthi, personal communication, October 15, 2015). Athletes who come from high median incomes (>US$70,000 per year) and who have private insurance have an increased risk of early sports specialization (N. Jayanthi, personal communication, October 15, 2015). Moreover, athletes who utilize private facilities are often encouraged to participate year round because those facilities are businesses that require income.

It is also important to recognize that chronological age is not equal to developmental age (Figure 2). For increased organized play over free play, there has also been reported to be a greater than 2 to 1 increased injury rate.[34] Athletes who specialize before the age of 12 years also may have a trend toward greater risks of being injured (N. Jayanthi, personal communication, October 15, 2015). Increased athlete exposure has a linear relationship to adjusted injury rate in high school athletes. For ice hockey, there is an increased dropout rate for those who participate in off-ice training at younger ages.

Figure 2.

Ten-year-old female basketball players.

An increased risk of hip injury has been shown in hockey players as they move through the ranks of organized hockey. As hockey players reached the midget level, with increased age and increased participation in hockey, the prevalence of factors associated with labral tears in the hip increased. When matched with skiers of the same age, hockey players had significantly higher prevalence of factors associated with labral tears in the hip. This study showed that risk factors may not only include years of play but may also include sports that put the hip at risk in young athletes.[38] Increased years of play was also a factor in young tennis players. A total of 148 youth tennis players were screened. Players were defined at risk of femoroacetabular impingement (FAI) if they had a positive anterior impingement test, a positive FABER (flexion, abduction, external rotation) distance test, or decreased internal rotation. Those players who had hips at risk played tennis longer compared with those without hips at risk (9.5 years compared with 8.6 years).[18]

Biomechanical Issues

Practitioners, trainers, parents, coaches, and athletes should be aware of the nonmodifiable risk factors that may predispose some athletes to a greater risk of injury. In the knee, anatomic factors include genu recurvatum, valgus alignment, increased lateral tibial slope greater than 4 degrees, and increased Beighton score.[7] These factors have been reported to be associated with a greater risk of knee injury. For elbow injuries associated with throwing sports, poor throwing mechanics such as increased trunk lean, improper stride, and “opening up early” are risk factors for elbow injury.[40] However, it is important to recognize that high throwing velocity increases elbow valgus moment, and younger pitchers may put greater forces on the medial elbow and be at a greater risk for injury.

Discussion

The topic of early sport specialization is receiving significant attention in the media.[42] There is a false or overstated importance of sports as it relates to individual roles in society; sports may be a financial bonanza for a very few but not the masses. The historical context of the need for large amounts of sport-specific practice may stem from the 10,000-hour rule,[21] but research has not substantiated this as a requirement for athletic success. One potential cause of this early sport specialization is that in North America particularly there is a competitive varsity school sports program and “select” teams which, while allowing for multisport participation, are often combined with non-school sport teams. There is an expectation for better athletes to participate in school teams as well as community (eg, regional, state) teams, which may set up these athletes to over-train. There is also a push for college scholarships where 14- and 15-year-olds are now committing to colleges based on their early teenage sports performance.

The biggest roadblock to making this culture shift may be the acknowledgement of coaches and parents that children are participating too early in sports, but “this doesn’t apply to ‘my’ sport or ‘my’ child.” This consensus meeting emphasized that we need to reset expectations of when competitive events occur and the level of difficulty or skill expected at each age level. Sports that have taken on this task with varying degrees of success are ice hockey in Canada and tennis in the United States.[30] In the United States, an ideal training program for safe development in a high-level junior tennis player has been recommended as follows[32]:

Minimum 12-year-old junior tournament player

Play less than 12 hours a week of organized tennis

Participate in less than 12 tournaments a year

Possibly consider another sport (soccer) with an off-season for tennis

Participate in 2+ hours a week of injury prevention training

However, within the current ranking system for athletes that tennis uses, this program will not allow an athlete to maintain a high ranking, highlighting a built-in contradiction.

Current recommendations for athletes who are involved in early sports specialization are as follows[37]:

Children who participate in more hours per week than their age, for more than 16 hours per week in intense training, and who are specialized in sport activities should be closely monitored for indicators of burnout, overuse injury, or potential decrements in performance due to overtraining.[31]

All youth (including inactive youth) can benefit from periodized strength and conditioning (eg, Integrative Neuromuscular Training [INT]) to help them prepare for the demands of competitive sport participation.

Youth who specialize in a single sport should plan periods of isolated and focused INT to enhance diverse motor skill development and reduce injury risk factors.

Early sports specialization has been identified as damaging for the future physical and mental health of the athlete. Future recommendations should include the following points:

A public health message that multisport participation will not diminish the athletic capabilities of athletes; we need better and more effective messaging with improved data.

A focused effort toward the importance of physical education as an opportunity for noncompetitive play and put it back into school curriculums.

Increased emphasis on the economic impact of a lack of physical fitness to health care costs as presented in obesity and various medical comorbidities.

Recognition that each sport has its own distinct loading pattern and a distinct overuse injury to go with it.

Identification of the optimal level of exposure to maximize training effect with minimal risk of injury needs to be identified.

Early sport specialization has not been shown to be beneficial for high-caliber athletic performance at the national team/Olympic/professional levels, and in fact may be detrimental.