Lin Min-Ju, Chen Trevor Chung-Ching, Chen Hsin-Lian, Wu Bo-Han, Nosaka Kazunori
a Department of Physical Education, Health and Recreation, National Chiayi University, 85 Wenlong Village, Minsyong Township, Chiayi County 62103, Taiwan.
b Department of Physical Education, National Taiwan Normal University, P.O. Box 97-71 Taipei, Taipei City 11699, Taiwan.
Appl Physiol Nutr Metab. 2015 Oct;40(10):1004-11. doi: 10.1139/apnm-2015-0107. Epub 2015 Jun 10.
This study investigated the magnitude and duration of the protective effect of low-intensity eccentric contractions (LowEC) against damage induced by maximal eccentric contractions (MaxEC) of the knee flexors (KF) and extensors (KE). Young men were assigned to 8 experimental groups and 2 control groups (n = 13/group); the experimental groups performed LowEC of KF or KE 2 days (2d), 1 week (1wk), 2 weeks (2wk), or 3 weeks (3wk) before MaxEC, while the control groups performed MaxEC of KF or KE without LowEC. The 2d, 1wk, 2wk, and 3wk groups performed 30 LowEC of KF or 60 LowEC of KE with a load of 10% of maximal voluntary isometric contraction strength on a resistance-training machine, and all groups performed 30 MaxEC of KF or 60 MaxEC of KE on an isokinetic dynamometer. Several muscle damage markers were measured from before to 2 days after exercise (LowEC) or from before to 5 days after exercise (MaxEC). No significant changes in any variables were evident after LowEC. The changes in all variables after MaxEC were smaller (P < 0.05) for the 2d and 1wk groups (e.g., peak creatine kinase activity: 1002 ± 501 IU/L; peak muscle soreness: 13 ± 5 mm) than for the control group (peak creatine kinase activity: 3005 ± 983 IU/L; peak muscle soreness 28 ± 6 mm) for both KE and KF. There were no significant differences between the 2d and 1wk groups or among the 2wk, 3wk, and control groups. These results show that LowEC provided 30%-66% protection against damage induced by MaxEC of KF and KE, and the protective effect lasted 1 week.
本研究调查了低强度离心收缩（LowEC）对膝关节屈肌（KF）和伸肌（KE）最大离心收缩（MaxEC）所致损伤的保护作用的程度和持续时间。年轻男性被分为8个实验组和2个对照组（每组n = 13）；实验组在MaxEC前2天（2d）、1周（1wk）、2周（2wk）或3周（3wk）进行KF或KE的LowEC，而对照组进行KF或KE的MaxEC但不进行LowEC。2d、1wk、2wk和3wk组在阻力训练机上以最大自主等长收缩力量的10%为负荷进行30次KF的LowEC或60次KE的LowEC，所有组在等速测力计上进行30次KF的MaxEC或60次KE的MaxEC。在运动（LowEC）前至运动后2天或运动（MaxEC）前至运动后5天测量了几种肌肉损伤标志物。LowEC后任何变量均无明显变化。对于KE和KF，2d组和1wk组MaxEC后所有变量的变化（例如，肌酸激酶活性峰值：1002±501 IU/L；肌肉酸痛峰值：13±5 mm）均小于对照组（肌酸激酶活性峰值：3005±983 IU/L；肌肉酸痛峰值28±6 mm）。2d组和1wk组之间以及2wk、3wk组和对照组之间均无显著差异。这些结果表明，LowEC对KF和KE的MaxEC所致损伤提供了30%-66%的保护，且保护作用持续1周。
