The aim of this randomized controlled trial was to compare the effects of plyometric jump training (PJT), with (RG) and without (NRG) between-session drill randomization, on jumping and sprinting abilities, change of direction speed, and technical performance. Youth male basketball players (age, 10.2 ± 1.7 years), were assigned to either the NRG (n=7), RG (n=6), or control group (n=6). Before and after the intervention, countermovement jump, 20-cm drop jump, 30-m sprint (with or without ball dribbling), and change-of-direction speed tests were completed. The PJT was applied twice per week for seven weeks. The only difference between PJT groups was the order of drill execution, in that for the RG the order of exercises for each session was randomized. A 3 (Groups) × 2 (Time: pre, post) ANOVA was used to detect differences between study groups. The analyses revealed significant main effects of time (all p<.01; effect sizes [ES] from partial eta squared values (η2) = 0.64-0.89) and group x time interaction (all p<.05; ES=0.31-51) for all examined variables. Post hoc analyses revealed moderate-large significant improvements for the RG (countermovement jump: 18.8%, ES=0.6; 20-cm drop jump: 23.9%, ES=0.80; 30-m sprint: 11.6%, ES=1.13; 30-m sprint with ball dribbling: 9.3%, ES=0.54; change of direction speed test: 14.6%, ES=1.82). In contrast, post hoc analyses revealed only small improvements for the NRG (20-cm drop jump: 14.1%, ES=0.36; 30-m sprint: 6.8%, ES=0.45; 30-m sprint with ball dribbling: 8.8%, ES=0.35; change of direction speed test: 10.5%, ES=0.49). Therefore, PJT could be more beneficial when executed with between-session randomization of drills.
Fonte: Journal of Sports Science and Medicine, 2018.