The 30-15 intermittent fitness test in young elite male soccer players: evaluating aerobic performance in relation to maturity offset

BACKGROUND: The developmental trajectory of young elite soccer players is influenced by maturation and physiological parameters. This study examined age-based differences in maturation, physical performance, and positional variations among young elite male soccer players using the 30-15 Intermittent Fitness Test (30-15 IFT) among 113 elite male players aged 11-17. METHODS: Assessments included peak height velocity (PHV), maturity offset, maximum running speed from the 30-15 IFT (MRS30-15IFT), and maximal oxygen uptake (VO(2)max). Age-related and positional differences were analyzed to identify significant variations across categories. RESULTS: Significant age-related differences were observed in maturation and performance parameters. U16 and U17 players differed in PHV (P=0.009), while maturity offset varied significantly across most categories except between U16 and U17. Aerobic performance, measured via MRS30-15IFT and VO(2)max, improved progressively with age; U12 players showed lower values than older groups (P<0.05). Strong correlations emerged between VO(2)max and maturity offset (r=0.73, P<0.001) and between MRS30-15IFT and maturity offset (r=0.73, P<0.001). Positional analysis revealed that central backs had lower PHV than midfielders and wingers in U12-U14 (P<0.015), while wingers showed higher VO(2)max than strikers in U15-U17 (P=0.042). CONCLUSIONS: Maturation and physiological performance parameters vary significantly across age categories in elite young soccer players. Position-specific differences in growth and aerobic capacity emphasize the importance of individualized training approaches to optimize development and performance.