Author(s): BENEDIKTSSON, S., SAEVARSSON, E., STEFANSDOTTIR, R., JOHANNSSON, E., ROGNVALDSDOTTIR, V., Institution: UNIVERSITY OF ICELAND, Country: ICELAND, Abstract-ID: 2260

INTRODUCTION:
The relative contribution of biological maturation and body composition to performance in youth female soccer remains uncertain. This study compared skeletal maturity, DXA-derived body composition and physical performance across coach-assigned ranking groups in 12-year-old female players within a community-club system.
METHODS:
Eighty-eight players (11.9 ± 0.3 years) completed bone age (BA) assessment from hand–wrist radiographs, DXA body composition testing and field-based measures including countermovement jump (CMJ), Illinois change-of-direction test with ball (ICODT-BALL), 40 m sprint and Yo-Yo Intermittent Recovery Test Level 1 (IR1). Correlations were examined between body composition and performance. Additionally, players were classified into three coach ranking groups. Between-group differences were analysed using one-way ANOVA with η² effect sizes and Holm-adjusted post-hoc comparisons.
RESULTS:
BA did not differ significantly between ranking groups (p = 0.590). Players in Rank 1 showed lower body fat percentage (p = 0.015). Clear performance differences were observed: Rank 1 demonstrated higher CMJ height (p < 0.001), faster ICODT-BALL times (p < 0.001) and faster 40 m sprint performance (p < 0.001). No significant differences were found for IR1 (p = 0.360). Bone age demonstrated only small correlation with sprint performance (r = −0.25).
CONCLUSION:
Coach ranking at age 12 primarily reflects speed, change-of-direction ability and jumping performance rather than BA. Body composition influences performance indirectly, suggesting that early ranking reflects current functional capacity more than maturity-related advantages.