Dallas George C, Pappas Panagiotis, Ntallas Constantinos G, Paradisis Giorgos P, Exell Timothy A
School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece -
School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece.
J Sports Med Phys Fitness. 2020 Jul;60(7):979-984. doi: 10.23736/S0022-4707.20.10384-0.
Plyometric exercises are often used to develop lower limb strength and performance-related biomechanics such as leg stiffness. However, the effectiveness of plyometric training may depend on participants' own training and performance demands. The purpose of this study was to examine the effect of plyometric training on Reactive Strength Index (RSI) and leg stiffness (Kleg) on young athletes of different sports.
Forty eight female athletes (25 Taekwondo (TKD) and 23 rhythmic gymnastics (RG), mean±SD: age: 8.94±2.50 years; mass: 29.73±7.69 kg; height: 138.84±11.90 cm; training experience: 4.62±2.37 years) participated in this study. Participants were randomly assigned to experimental (PT, N.=24) and control (CG, N.=24) groups. The PT group followed a twice-weekly plyometric training program for 4 weeks. Plyometric drills lasted approximately 5-10 s, and at least 90 s rest was allowed after each set. To examine RSI, participants performed trials of five maximal CMJs. Submaximal hopping (20 hops) was performed in order to examine leg stiffness.
Significant interaction effect was found for RSI and the post hoc analysis showed that RSI significantly increased by 35% (P=0.017) in RG athletes, whereas a significantly reduction by 28% (P=0.004) was revealed in TKD athletes. The interaction effect between time and group was statistically significant for Kleg (P<0.05) with Kleg significantly increasing by 31% (P=0.008) in TKD athletes, but remaining unchanged (P>0.05) in RG athletes.
The results showed that the effect of a 4-week plyometric training program on RSI and leg stiffness is sport dependent. Further, the applied plyometric program was effective in reducing ground contact time and therefore increasing leg stiffness.
增强式训练常用于发展下肢力量以及与运动表现相关的生物力学指标，如腿部僵硬度。然而，增强式训练的效果可能取决于参与者自身的训练情况和运动表现需求。本研究的目的是探讨增强式训练对不同运动项目的年轻运动员反应力量指数（RSI）和腿部僵硬度（Kleg）的影响。
48名女性运动员（25名跆拳道（TKD）运动员和23名艺术体操（RG）运动员，平均±标准差：年龄：8.94±2.50岁；体重：29.73±7.69千克；身高：138.84±11.90厘米；训练年限：4.62±2.37年）参与了本研究。参与者被随机分为实验组（PT，n = 24）和对照组（CG，n = 24）。PT组进行为期4周、每周两次的增强式训练计划。增强式训练动作持续约5 - 10秒，每组训练后至少休息90秒。为检测RSI，参与者进行5次最大纵跳测试。为检测腿部僵硬度，进行次最大强度单脚跳（20次单脚跳）。
发现RSI存在显著的交互作用效应，事后分析表明，RG运动员的RSI显著提高了35%（P = 0.017），而TKD运动员的RSI显著降低了28%（P = 0.004）。对于Kleg，时间和组间的交互作用效应具有统计学意义（P < 0.05），TKD运动员的Kleg显著增加了31%（P = 0.008），而RG运动员的Kleg保持不变（P > 0.05）。
结果表明，为期4周的增强式训练计划对RSI和腿部僵硬度的影响因运动项目而异。此外，所应用的增强式训练计划在减少地面接触时间从而增加腿部僵硬度方面是有效的。
