Effects of an 8-Week In-Season Explosive Power Training Program on Neuromuscular Performance and Lower-Limb Asymmetries in Young Male Soccer Players

Abstract Vasileiou, SS, Asimakidis, ND, Dalamitros, AA, and Manou, V. Effects of an 8-week in-season explosive power training program on neuromuscular performance and lower limb asymmetries in young male soccer players. J Strength Cond Res 38(12): 2121–2128, 2024—This study analyzed the effects of incorporating 8 weeks of twice-weekly explosive power training on neuromuscular performance and lower-limb asymmetries applied to soccer. Thirty-five young male soccer players were randomly assigned to either the experimental group (EXP: n = 18; mean age: 13.7 ± 0.8 years; height: 166.9 ± 8.4 cm; body mass: 58.5 ± 12.8 kg) or the control group (CON: n = 17; mean age: 13.7 ± 0.9 years; height: 168.8 ± 9.1 cm; body mass: 58.0 ± 11.4 kg). Before (TP1) and after the training period (TP2) neuromuscular performance (countermovement jump [CMJ], 10 and 20 m sprint times [T10 and T20], change of direction ability [COD]) and lower-limb asymmetries (single-leg CMJ [SLCMJ]) were evaluated. The asymmetry index (AI) for COD and CMJ tests was also calculated. Significant differences (from TP1 to TP2) were revealed for all the tested parameters in the EXP group (1.50–4.9%, p < 0.00 to 0.12, effect size [ES] = −0.44 to 0.27). For the CON group, T10, T20 505 for nondominant limb and SLCMJ performances for both limbs were significantly improved (0.85 to 1.5%, p < 0.00 to 0.21, ES = −0.36 to 0.37). Finally, the AI remained relatively unchanged for both tests and groups (1.28–3.33%, p = 0.162–0.521). These results indicate that adding twice-weekly explosive power training for 8 weeks can improve neuromuscular performance and reduce lower-limb asymmetries to a greater degree than soccer training alone in young male soccer players.