Objective The impact, positive or negative, of youth sport specialisation (YSS) on short-term and long-term performance is not fully understood; however, the desire to maximise performance goals is generally considered the primary reason children and adolescents specialise at a young age. We performed a systematic review of original research to establish the association of YSS and task-focused or career-focused performance outcomes. Design Systematic review. Data sources Databases searched include PubMed, EMBASE, Cochrane, CINAHL and SPORTDiscus. Eligibility criteria We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify peer-reviewed research articles published in English between 1 January 1990 and 31 December 2018 that reported original findings on the association of YSS and performance outcomes. Studies without an explicit measure of sport specialisation, for example, volume measures without measuring sport specialisation, were excluded. Results Twenty-two articles were included in the final review; 15 addressed career performance outcomes and 7 considered task performance outcomes. All identified studies were cross-sectional or retrospective in design. The proportion of elite athletes who specialised early ranged between 7% and 85%, depending on sport and definition of specialisation. Elite athletes often specialised between the ages of 14 and 15 compared with their non-elite or semi-elite peers who typically specialised prior to 13 years. In addition, neuromuscular control, anterior reach asymmetry and physical task outcomes did not differ by specialisation status. Conclusion The volume and methodological rigour of published research in this field are limited. Our review suggests that YSS is not required to achieve success at elite levels. YSS also does not appear to improve task-related performance (eg, anterior reach, neuromuscular control) outcomes for specialised athletes when compared with non-specialised athletes during childhood and adolescence.

Sport specialisation is becoming increasingly common among youth and adolescent athletes in the USA and many have raised concern about this trend. Although research on sport specialisation has grown significantly, numerous pressing questions remain pertaining to short-term and long-term effects of specialisation on the health and well-being of youth, including the increased risk of overuse injury and burnout. Many current elite athletes did not specialise at an early age. Methodological and study design limitations impact the quality of current literature, and researchers need to prioritise pressing research questions to promote safe and healthy youth sport participation. The American Medical Society for Sports Medicine hosted a Youth Early Sport Specialization Summit in April 2019 with the goal of synthesising and reviewing current scientific knowledge and developing a research agenda to guide future research in the field based on the identified gaps in knowledge. This statement provides a broad summary of the existing literature, gaps and limitations in current evidence and identifies key research priorities to help guide researchers conducting research on youth sport specialisation. Our goals are to help improve the quality and relevance of research on youth sport specialisation and to ultimately assure that opportunities for healthy and safe sport participation continue for all youth.

This Clinical Report was reaffirmed July 11, 2023.: Participation in youth soccer in the United States continues to increase steadily, with a greater percentage of preadolescent participants than perhaps any other youth sport. Despite the wide-ranging health benefits of participation in organized sports, injuries occur and represent a threat to the health and performance of young athletes. Youth soccer has a greater reported injury rate than many other contact sports, and recent studies suggest that injury rates are increasing. Large increases in the incidence of concussions in youth soccer have been reported, and anterior cruciate ligament injuries remain a significant problem in this sport, particularly among female athletes. Considerable new research has identified a number of modifiable risk factors for lower-extremity injuries and concussion, and several prevention programs have been identified to reduce the risk of injury. Rule enforcement and fair play also serve an important role in reducing the risk of injury among youth soccer participants. This report provides an updated review of the relevant literature as well as recommendations to promote the safe participation of children and adolescents in soccer.

Preterm birth interrupts the third trimester of gestation, resulting in altered development of several key physiological systems, including the autonomic nervous system, though the long-term implicat...

Although increased training load (TL) and impaired sleep are associated with decreases in subjective well-being in adult athletes, these relationships among female youth athletes are unclear. It is unknown whether the effects of sleep and TL on well-being are independent or whether alterations in sleep mediate the effects of TL on subjective well-being. Sleep and TL exert independent effects on subjective well-being among youth athletes, although alterations in sleep mediate a significant portion of the effect of TL on well-being in female youth athletes. Prospective cohort study. Level 4. A total of 65 female soccer athletes (age range, 13-18 years) were monitored for 1 year. Daily TL was determined by session rating of perceived exertion and converted to z-scores. Every morning, participants recorded sleep duration in hours and rated stress, mood, fatigue, and soreness on a scale from −3 to +3 (worst to best). Linear mixed-effects models and mediation analysis were used to evaluate the independent effects of TL and sleep on well-being. Average sleep duration was 7.9 ± 1.4 hours during the study period. In the multivariable model, TL and sleep duration were independently associated with fatigue (TL: β = −0.19, P < 0.001; sleep: β = 0.15, P < 0.001), mood (TL: β = −0.030, P = 0.014; sleep: β = 0.13, P < 0.001), stress (TL: β = −0.055, P = 0.001; sleep: β = 0.13, P < 0.001), and soreness (TL: β = −0.31, P < 0.001; sleep: β = 0.022, P = 0.042). Sleep duration mediated a significant portion of the effect of TL on mood (26.8%, P < 0.001), fatigue (12.6%, P < 0.001), and stress (24.5%, P < 0.001). Among female youth athletes, decreased sleep duration and increased TL are independently associated with impairments of subjective well-being. In addition, decreased sleep mediates a significant portion of the negative effect of increases in TL on subjective well-being. Monitoring and promoting sleep among female adolescent athletes may significantly improve subjective well-being, particularly during periods of increased TL.