Effect of 10-Week Plyometric Training on Anaerobic Performance and Biomechanical Properties of the Muscles in Football Players: Randomized Controlled Trial

This study investigated the effects of a 10-week plyometric training program on sprint performance, reactive power, and biomechanical muscle properties in soccer players. Twenty soccer players were randomly assigned to an experimental group (n = 10) or a control group (n = 10). Both groups maintained their regular weekly training, with the experimental group performing additional plyometric sessions twice weekly. Pre- and post-intervention assessments included 5 m and 30 m sprint times, Reactive Strength Index (RSI), and biomechanical properties (tension, stiffness, elasticity) of the rectus femoris (RF) and vastus lateralis (VL). The experimental group demonstrated significant improvements in 5 m (p < 0.01; ES = 1.44) and 30 m (p < 0.01; ES = 1.11) sprint times and RSI (p < 0.05; ES = 0.87). No significant changes were observed in muscle tension, stiffness, or elasticity at the group level. However, correlations indicated that higher baseline elasticity in the VL was linked to greater 5 m sprint improvements, while changes in RF elasticity were negatively associated with 5 m sprint gains. These findings suggest that plyometric training effectively enhances short-distance sprint performance and reactive power in soccer players. Although group-level biomechanical properties did not change significantly, individual variability in muscle elasticity may modulate training outcomes, supporting the integration of plyometric exercises into soccer training regimens.