Variability in selected components of youth soccer match performance relates to physical maturity but not to chronological age

This study, firstly, established the between-match variability of soccer-match performance among under-14 players and, secondly, investigated the relationship between match performance variability and both maturity and chronological age. Participants were recruited from two under-14 youth squads in England. The between-match variation of each player was quantified using the Coefficient of Variation (CV %) over a minimum of two and a maximum of five matches (N.=110). Measurements included passing frequency per minute, heart rate (bpm), post-match Rating of Perceived Exertion (RPE) and both total and high-intensity metres per minute (total m.min⁻¹ HIM m.min⁻¹, respectively), derived from Global Positioning Systems (GPS). Assessments of physical maturity (age at peak height velocity; APHV) were also conducted. Passes.min⁻¹ 15.2±5.4%) were the most variable, followed by HIM m.min⁻¹ 13.9±4.9%) and RPE (13.7±4.4 %). The least variable components were HR (4.1±2.6%) and total m.min⁻¹ (5.5±4.7 %). There were strong relationships between APHV and CV% of HIM m.min⁻¹ r=0.69, r²=0.47), APHV and CV% of average match HR (r=0.54, r²=0.29) and APHV and CV%of RPE (r=0.63, r²=0.40). Physical maturity, but not the chronological age, of youth soccer players explains between 29% and 47% of the variance in components of match performance. Our findings reaffirm, for different reasons, the importance of differentiating between maturational status and chronological age when evaluating youth soccer players' performance.