Plyometric Performance in Under-10 Soccer Players: Effects of Modified Competitions and Maturational Status

The aim of this study was to examine the effects of different competition formats on the plyometric performance of under-10 soccer players, while analysing the influence of maturational status. A quasi-experimental design was applied, involving 50 players (mean age = 9.47 ± 0.54 years). Kinematic load was recorded using Wimu™ inertial accelerometers, and maturational status was evaluated using the percentage of predicted adult height (%PAH) as a moderating factor. Results indicate that while total impact volume did not show significant differences (p = 0.082), the modified format (MD1) showed a reduction in biomechanical intensity per action. Very large differences were reported in mean take-off acceleration (p = 0.001; BF₁₀ = 23.97) and landing acceleration (p < 0.001; BF₁₀ = 70.57). Furthermore, biological maturation was found to be an essential moderating factor, with a threshold of significance identified at 75.5% %PAH. The results of this study show that modified rules can be a good tool for modulating plyometric intensity without compromising the volume of exposure to the stimulus. These findings may highlight indicate the need to implement an individualized approach, based on maturational thresholds, to optimise adaptations and ensure joint safety during long-term development.