Allometric scaling and age-related differences in change of direction speed performances of young soccer players

Purpose: The purposes of this study were to compare change of direction speed (CODS) performances between different age categories (i.e., U-10, U-12, U-13, and U-18) and to develop allometric exponents for scaling this quality. Material and method: Data were gathered with the participation of 101 male soccer players (mean ± SD; age = 12.5 ± 2.9 years, mass = 44.4 ± 14.7 kg, height = 149.3 ± 17.7 cm, and leg length = 75.7 ± 13.1 cm). All players performed the Illinois change of direction speed test (ICDST). Results: U-18 players achieved significantly better results in ICDST compared with the other groups, whereas U-10 players had the lowest performances (F = 48.78, P < 0.0001). In regards to U-12 and U-13 soccer players, no significant differences were established between them (P > 0.05). The ICDST performances were significantly associated with body mass (r = −0.58; P < 0.0001), height (r = −0.75; P < 0.0001) and leg length (r = −0.75; P < 0.0001). No correlations between allometrically scaled ICDST performance and anthropometric measures were observed (all P > 0.05), indicating the effectiveness of allometric exponents in partialing out the effect of anthropometric measures on ICDST's compared to ratio scaling. Conclusion: Results indicated differences in CODS performance among soccer players of different age categories. These results demonstrated that developing allometric exponents are effective in controlling for anthropometric measures.