LAUSR

This study aimed to compare the effects of one vs. two sessions of equal-weekly volume plyometric training (PT) across 8 weeks on measures of athletic performance (i.e., sprint-time, change of direction [CoD], jumping ability, and muscle strength) in prepuberal male soccer players. Thirty participants were randomly assigned either to one session PT group (1SPT [n=15]) or two sessions PT group (2SPT [n=15]). Plyometric training was integrated into their regular soccer training routine. Pre- and post-training tests for the assessment of sprint-time (e.g., 5-m, 10-m, 20-m, and 30-m), CoD (e.g., T-test and modified Illinois change of direction test [MICODT]), jumping ability (e.g., standing long jump [SLJ], counter-movement jump [CMJ], and squat jump [SJ]), muscle strength (reactive strength index [RSI]), and kicking distance were conducted. Results showed a main effect of time for 5-m sprint-time performance (F(1,56)=4.00, ES=0.53 [medium], p=0.05), T-test (F(1,56)=23.19, ES=1.28 [large], p<0.001), MICODT (F(1,56)= 5.72, ES=0.94 [large], p=0.02), SLJ (F(1,56)=16.63, ES=1.09 [large], p<0.001), CMJ (F(1,56) =15.43, ES= 1.04 [large], p<0.001), SJ (F(1,56) =20.27, ES=1.20 [large], p<0.001), RSI (F(1,56)=26.26, ES=1.36 [large], p<0.001), and kicking distance (F(1,56)=47.19, ES=1.83 [large], p<0.001). There were no training group × time interactions in all the measured outcomes. In conclusion, when an equated moderate volume of jumps is performed, higher PT frequency across 8 weeks has no extra-effects on prepuberal male soccer players' measures of athletic performance. The present findings may help optimizing PT interventions dedicated to prepuberal male soccer players.