Predictors of Junior Versus Senior Elite Performance are Opposite: A Systematic Review and Meta-Analysis of Participation Patterns.

Excess childhood/adolescent specialized practice may hinder athletes' long-term development through overuse injury, burnout, suboptimal athlete-sport match, and limiting long-term learning capital. By contrast, adult world-class athletes' childhood/adolescent multi-sport practice with reduced main-sport practice implied a relatively resource-preserving, cost-reducing, and risk-buffering pattern that yielded greater long-term sustainability and practice efficiency.