Biological Maturation and Physical Performance in Youth Football: Associations Across Professional and Non-Professional Environments

Background: Biological maturation is a major determinant of physical performance in youth football, although the previous evidence suggests that training context may influence maturation–performance associations. This study investigated the association between biological maturation and physical performance in youth football players from professional and non-professional settings. Methods: A total of 302 male football players (Under-10 to Under-14) from a professional academy (n = 122) and non-professional clubs (n = 180) participated. Biological maturation was estimated using maturity offset and age at peak height velocity (aPHV). Physical performance was assessed through standing broad jump, T-test agility, and sit-and-reach tests. General Linear Models and stratified correlation analyses were used to examine the interaction between maturation, age category, and training environment. Relative age distribution was also described. Results: Professional academy players demonstrated superior explosive power, agility, and flexibility across most age categories compared with non-professional players. Significant associations between biological maturation and physical performance were observed mainly in the non-professional environment, particularly for agility and explosive power, whereas few significant relationships emerged in the professional academy. Significant interactions between training environment, age category, and maturation status were found for all performance measures, with the strongest effect observed for agility. A relative age effect emerged only in the older professional categories. Conclusions: Associations between biological maturation and physical performance differed according to training environment in youth football players. Stronger maturation–performance relationships were generally observed in non-professional settings, whereas weaker associations emerged in the professional academy. However, due to the cross-sectional design and the likely interdependence between maturation, selection, and training exposure, causal interpretations cannot be inferred.