INTRODUCTION:
Youth of the same chronological age may differ substantially in biological maturity, making it essential to account for maturation when comparing physical performances within age groups, as maturity influences the development of specific fitness components. Several predictive equations have been proposed to estimate maturation status, either via age at peak at height velocity (APHV) or predicted adult height (PAH). This study examined the concordance among commonly used predictive methods for classifying players by maturation status and, to the best of our knowledge, investigated for the first time whether differences in physical performance are more closely related to maturation or chronological age.
METHODS:
A total of 192 youth male soccer players (U14=55, U15=55, U16=43, U17=39) were assessed. Measurements included anthropometry, sprint performance (10 m and 30 m), countermovement jump (CMJ), and endurance capacity (Yo-Yo Intermittent Recovery Test, YYIRT1). APHV was estimated using Mirwald, Moore, Moore2, and Fransen methods, while PAH was calculated using the Khamis-Roche method. Players were classified by maturation status using both conservative and less conservative criteria. Agreement among APHV estimates was assessed using Bland-Altman analysis, and classification agreement was evaluated with Fleiss’ Kappa. The impact of maturation on performance was examined using two-step linear regression models to assess changes in explained variance (R²).
RESULTS:
All predictive methods yielded significantly different APHV estimates (p < 0.05); regression slopes were significant in all comparisons, indicating increasing disagreement at higher APHV values. Classification agreement was weak under both criteria (Kappa = 0.521 and 0.549). For the 10 m and 30 m sprint performance, inclusion of maturation status significantly improved R² in most cases (ΔR² = 0.025-0.118), indicating that maturation explained an additional 2–11% of variance. For YYIRT1, maturation did not improve models beyond chronological age. For CMJ, the contribution of maturation was limited, with only four methods showing a significant increase in R².
CONCLUSION:
Accounting for biological maturation independently of chronological age is essential, as failing to do so confounds their respective effect. Maturation influences performance unevenly, showing stronger associations with sprint ability than with strength or endurance, highlighting the need for further targeted research.