Effects of drop jump training on physical fitness in youth male volleyball players: Comparing maximal rebound height vs fixed drop height training

Abstract

Abstract Background It has previously been shown that drop jump height is an effective programming parameter in plyometric jump training. Less is known on the usage of maximal rebound jump height from a distinct drop height as a parameter for individualized plyometric jump training. Aim This study examined the effects of 8-weeks of two drop jump (DJ) training modalities using maximal rebound height (MRHT) vs fixed (FDHT) drop height programming approaches on selected measures of physical fitness in young volleyball players. Methods Thirty male youth volleyball players aged 14 to 16 years were randomly assigned to a MRHT (n = 15) or a FDHT (n = 15) group. The MRHT group performed DJ exercises using a drop height according to the individual’s maximal rebound jump height from 20-cm, 30-cm, 40-cm, and 50-cm drop heights. The FDHT group performed DJs following a standardized drop height (30-cm) across the 8-week intervention period. The overall training volume was similar between MRHT and FDHT with 3 sets of 10 repetitions of DJ exercises per session. Pre- and post-training, DJs were tested from 30, 40, and 50-cm drop heights. In addition, dynamic balance (Y-balance test) as well as linear sprint and change-of-direction (CoD) speed were assessed. Results Significant group-by-time interactions were found for DJ, balance, and linear sprint tests (p < 0.0001; d = 0.12–0.88) but not for CoD speed. Post-hoc tests showed significant improvements in favor of the MRHT group for DJ heights from 30-cm (Δ20.4%, p < 0.0001, d = 6.31), 40-cm DJ (Δ20.3%, p < 0.0001, d = 3.46), 50-cm DJ (Δ18.3%, p < 0.0001, d = 4.99), 5-m (Δ9.2%, p < 0.001, d = 1.21) and 20-m (Δ7.4%, p < 0.01, d = 1.60) linear sprint speed. Conclusions MRHT is a safe and effective training regime to improve DJ and linear sprint speed performance. Due to the importance of vertical jumps and short accelerations for overall competitive performance in volleyball, our results suggest that young male players should perform MRHT as part of plyometric jump training if the goal is to improve acceleration and vertical jump performance.