Validated soccer simulation protocol for youth: evidence from U13–U15 players

Introduction: A football simulation protocol is a standardized exercise protocol designed to replicate the physical and physiological demands of an actual football match under controlled conditions. Objective: The aim of this study was to assess the reliability and validity of a soccer simulation protocol designed for U13, U14, and U15 soccer players. Methodology: Twenty (n=20) outfield players (U13: n = 7, 1.57 ± 0.06 m, 47.8 ± 6.8 kg; U14: n = 7, 1.70 ± 0.06 m, 60.4 ± 8.4 kg; U15: n = 6, 1.75 ± 0.07 m, 58.1 ± 2.6 kg) from Auckland Football Federation volunteered to participate in the study. Participants completed the protocols on two occasions to determine test–retest reliability. Each protocol required players to cover a total running distance equivalent to match play at varying intensities in a cyclical pattern, divided into four exercise blocks separated by five-minute recovery periods. Results: No significant differences were observed between trials in heart rate, countermovement jump, sprint speed and perceptual scales (P>0.05). Test–retest analysis demonstrated moderate to high reliability, with intraclass correlation (r= 0.50 to 0.80) and low standard error of measurement. Concurrent validity assessment showed significant positive correlations (r= 0.77 to 0.82) between match-play and the protocols for all age groups. Discussion: The study validated a soccer-specific simulation protocol for under 13 to under 15 players, facilitating more comprehensive investigation and bridging the performance gap between youth and adult players. Conclusion: The protocols is a valid and practical tool for assessing youth players.