Influence of Age Category and Anthropometric Characteristics on Aerobic and Explosive Performance in Youth Soccer Players

Youth soccer performance is influenced by multiple factors, including age, body size, and physical capacities, but the relative contribution of these variables to aerobic and explosive performance remains unclear. Understanding these relationships can improve the interpretation of field tests and support individualized training prescription. This study was designed to examine the association of age category, body mass, and height with physical performance in youth soccer players by jointly considering aerobic and explosive capacities, in order to support the interpretation of field tests within training prescription. Forty-five male players (15 U16, 15 U17, 15 U19) from the same club were assessed across two standardised on-field testing sessions, including the 45–15 test (estimated maximal aerobic speed, MAS) and vertical jump tests (squat jump, SJ; countermovement jump, CMJ; countermovement jump with free arms, CMJ_FH). Performance variables (SJ, CMJ, CMJ_FH, MAS) were treated as outcomes, while category, body mass, and height were included as predictors. A multivariate analysis was performed, followed by univariate analyses for each indicator. Results showed a significant multivariate effect of age category on overall performance (p < 0.001; η2p = 0.482), whereas height and body mass were not significant (p > 0.05). In univariate analyses, age category was associated with all variables: SJ (p = 0.005; adj. R2 = 0.160), CMJ (p < 0.001; adj. R2 = 0.287), CMJ_FH (p = 0.004; adj. R2 = 0.173), and MAS (p < 0.001; adj. R2 = 0.352). Performance increased progressively from U16 to U17 to U19, with larger between-category differences in aerobic capacity. In conclusion, age category was more strongly associated with the performance profile than height and body mass when considered jointly; these findings should be interpreted in light of the observational design and the lack of biological maturation measures.