Youth athlete development and the burden of musculoskeletal injuries: Implications of early sport specialisation.

Youth sport participation has increased substantially over the past two decades, bringing well-documented physical, social and psychological benefits. However, this growth has been accompanied by a rising burden of musculoskeletal injuries among young athletes, with prevalence rates ranging from 34% to 65%. Overuse injuries account for up to 50% of all youth sport injuries, while severe injuries such as anterior cruciate ligament reconstructions have increased markedly over the past two decades. Early sport specialisation (ESS), defined as year-round, intensive, single-sport training that excludes other sports, has gained traction as a perceived pathway to elite performance. However, current evidence does not support ESS as a reliable predictor of long-term athletic success. The majority of successful senior athletes were not standouts as youths, and early performance is a poor forecaster of adult excellence. Evidence examining associations between ESS and injury risk remains limited and methodologically inconsistent. Definitions of ESS vary substantially, measurement tools incompletely capture the construct, and relatively few high-quality empirical studies are available. More importantly, ESS may be better viewed as a proxy for a broader constellation of interacting exposures, including cumulative training load, recovery practices, biological maturation, variety of movement experiences and psychosocial stressors, which are more plausible determinants of injury risk and athlete development. Rather than asking whether ESS is inherently harmful, a more informative question is which combinations of training, developmental and environmental factors best support both performance progression and long-term athlete health. Until these mechanisms are more clearly understood, a cautious, individualised and evidence-informed approach to youth athlete development is warranted.