Zimmermann Haiko Bruno, Costa Filipe Estácio, Sakugawa Raphael, MacIntosh Brian, Diefenthaeler Fernando, Dal Pupo Juliano
Biomechanics Laboratory, Center of Sports, Federal University of Santa Catarina, Florianopolis, Brazil.
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada.
Eur J Sport Sci. 2022 Jun;22(6):857-866. doi: 10.1080/17461391.2021.1916083. Epub 2021 May 16.
: The objective of this study was to evaluate a plyometric conditioning activity (3 sets of 5 countermovement jumps, [CA]) for twitch properties and voluntary knee extension. : After a familiarization session, fourteen highly trained sprint athletes, 12 men (23.25 ± 7.17 years) and 2 women (23.0 ± 2.8 years) performed 2 experiments, each in a randomized order (crossover design). In one experiment, the time-course of twitch contractile properties was evaluated with and without the previous CA at 2, min intervals to 10 min of recovery. In the second session, maximal voluntary knee extension was evaluated at the same recovery intervals, for control and experimental condition in random order. : Mixed-model ANOVA with Bonferroni post-hoc revealed significant differences between pre-test and 2 min ( < 0.01, ES = 0.42) and 4 min ( < 0.01, ES = 0.20) for peak twitch torque of quadriceps femoris muscles confirming postactivation potentiation [PAP] at these times. Twitch rate of torque development (RTD) was significantly greater than pre-test value only at 2 min ( < 0.01, ES = 0.58) after the CA. Twitch contraction time and ½ relaxation time were not significantly difference from pre-test values after the CA ( > 0.05). No significant difference was observed for voluntary RTD following CA. : The plyometric CA increased twitch peak torque and RTD consistent with PAP; however, there was no effect of CA on voluntary RTD of knee extension at any time after the plyometric CA. Even with PAP confirmed, we observed that the CA fails to improve isometric RTD of quadriceps femoris muscles. HighlightsA plyometric CA significantly increased twitch peak torque (at 2 and 4 min) and twitch rate of torque development (at 2 min) of quadriceps femoris muscles, indicating postactivation potentiation (PAP).No effect was observed for twitch contraction time and ½ relaxation time after the CA.No improvement was observed on voluntary rate of torque development evaluated at the same time intervals.
本研究的目的是评估一种增强式训练活动（3组，每组5次下蹲跳，[CA]）对抽搐特性和主动膝关节伸展的影响。在一次熟悉训练后，14名训练有素的短跑运动员，12名男性（23.25±7.17岁）和2名女性（23.0±2.8岁）进行了2项实验，每项实验均采用随机顺序（交叉设计）。在一项实验中，在恢复至10分钟的过程中，每隔2分钟评估有或没有先前CA时的抽搐收缩特性的时间进程。在第二节实验中，在相同的恢复间隔下，以随机顺序评估最大主动膝关节伸展的对照和实验条件。采用混合模型方差分析和Bonferroni事后检验，结果显示股四头肌峰值抽搐扭矩在测试前与2分钟（P<0.01，ES=0.42）和4分钟（P<0.01，ES=0.20）之间存在显著差异，证实了这些时间点的激活后增强作用[PAP]。仅在CA后2分钟，扭矩发展速率（RTD）显著高于测试前值（P<0.01，ES=0.58）。CA后抽搐收缩时间和半松弛时间与测试前值无显著差异（P>0.05）。CA后主动RTD未观察到显著差异。增强式CA增加了与PAP一致的抽搐峰值扭矩和RTD；然而，在增强式CA后的任何时间，CA对膝关节伸展的主动RTD均无影响。即使证实了PAP，我们观察到CA未能改善股四头肌的等长RTD。要点增强式CA显著增加了股四头肌的抽搐峰值扭矩（在2分钟和4分钟时）和扭矩发展速率（在2分钟时），表明激活后增强作用（PAP）。CA后抽搐收缩时间和半松弛时间未观察到影响。在相同时间间隔评估的主动扭矩发展速率未观察到改善。
