China Institute of Sport and Health Science, Beijing Sport University, Beijing, China.
Department of Physical Education and Research, Yanzhou High School of Zhongshan, Zhongshan, China.
Int J Sports Physiol Perform. 2024 Aug 21;19(10):1115-1121. doi: 10.1123/ijspp.2024-0071. Print 2024 Oct 1.
To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance.
Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention.
Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P = .017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P < .001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P < .001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥ .294).
Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading.
比较 6 周杠铃负重跳深蹲（WJS）训练结合和不结合离心负荷减少对爆发力的影响。
20 名训练有素的男性运动员被随机分配到实验组（n = 10）或对照组（n = 10）。参与者每周进行 2 次 12 次 WJS 训练（每组 5 次，杠铃深蹲 30%的 1 次重复最大重量[1RM]），共 6 周。对照组使用 0%的离心负荷（即传统 WJS），实验组使用机械制动装置减少 50%的离心负荷（即 1RM 的 15%的离心负荷）。在干预前后（预测试和后测试）进行了包括反跳跳、20 米冲刺、立定跳远和 1RM 杠铃深蹲等表现评估。
实验组和对照组的反跳跳高度均显著增加（+6.4%[4.0%]比+4.9%[5.7%]；P<0.001）和峰值功率输出（+2.3%[2.7%]比+1.9%[5.1%]；P=0.017），20 米冲刺速度更快（+9.4%[4.8%]比+9.2%[5.5%]；P<0.001），立定跳远距离更长（+3.1%[2.5%]比+3.0%[3.3%]；P<0.001），1RM 深蹲更高（+6.4%[4.0%]比+4.9%[5.7%]；P<0.001），从预测试到后测试。然而，任何变量的条件×时间交互都没有显著差异（所有 P≥0.294）。
结合和不结合离心负荷减少的 WJS 训练方法均可有效提高爆发力。然而，对于处于伤病康复后期或高强度训练阶段的运动员来说，与传统等动加载相比，减少离心负荷可能是一种更能耐受的策略，可实现类似的性能提升。
