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 XX(X): 000–000, 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 (TP 1 ) and after the training period (TP 2 ) 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 TP 1 to TP 2 ) 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.