Interactions Between Chronological Age, Relative Age, and Maturation on Training Load, Recovery, and Technical– Tactical Performance in Pre-Pubertal Sub-Elite Football Players

Abstract

Chronological age, relative age effects, and biological maturation are key factors influencing training load exposure and performance development in youth football. However, their combined and independent contributions to external and internal load, recovery status, and technical–tactical performance in sub-elite pre-pubertal players remain insufficiently understood. Forty sub-elite pre-pubertal male football players (U11 = 30; U13 = 10) were monitored across four training sessions and one official match. External load was assessed using GPS-derived metrics (total distance, high-speed running [HSR], high-intensity distance, average speed [AvS], maximal running speed [MRS], accelerations, and decelerations). Internal load was quantified via heart rate and session rating of perceived exertion (s-RPE). Recovery status was evaluated using the Total Quality Recovery (TQR) scale. Technical–tactical performance was assessed through decision-making index, motor effectiveness index, and overall performance index. Relative age was classified by birth quartiles, and biological maturation was estimated using maturity offset (Mirwald method; median = −1.42 years). Group comparisons, effect sizes (Cohen’s d), and multiple regression analyses were conducted. Chronological age showed a clear influence on locomotor intensity, with U13 players demonstrating higher HSR (p = 0.02, d = 1.15), MRS (p = 0.03, d = 0.84), and AvS (p = 0.05, d = 0.82) compared to U11 players. Relative age quartiles revealed negligible differences, except for a higher number of sprints in early-born players (p = 0.03, d = −0.64). When classified by maturity offset, early pre-peak height velocity (pre-PHV) players performed more accelerations and decelerations (p < 0.05), whereas later pre-PHV players tended to reach higher running intensities. Regression analyses indicated that competition level (U13) was the strongest predictor of HSR (β = 0.65, p < 0.01) and MRS (β = 0.52, p = 0.02), while relative age and maturity offset showed minor effects (R² = 0.15–0.33). Internal load, recovery, and technical–tactical outcomes displayed low explained variance (R² < 0.10). Chronological age emerged as the primary determinant of external load in sub-elite pre-pubertal football players, whereas relative age and biological maturation exerted limited independent effects. These findings highlight the dominant role of competition level over maturation-related factors in shaping external load profiles during early developmental stages.