The maturity status but not the relative age influences elite young football players' physical performance.

Talent identification and selection process in young football is based on coaches' decisions regarding the players' performance at early ages. The aim of this study was to show how the maturity status and the relative age impact on young football players' physical performance and their coaches' efficacy expectations. The physical performance (1RM, Peak power output [PPO], 30-m sprint and t-test) of 118 young football players (U13 to U15; and their coaches' efficacy expectations were assessed. Relative age was calculated according to the players' date of birth within their selection year. The maturity status was estimated as the years from/to their peak height velocity (PHV). Linear regression analyses showed a significant relationship between players' physical performance and their maturity status but not with their relative age. In contrast, the maturity status of players only was associated to the coaches' efficacy expectations in the 1RM and PPO tests, whereas the relative age was a predictor of the coaches' expectations about players' performance in the t-test. These findings may be important for coaches and managers in young football academies since inter-individual differences in the maturity status but not in the relative age are related to physical performance despite the coaches' expectations.