Oliveira Anderson Souza, Gonçalves Mauro
Biomechanics Laboratory, Institute of Biosciences, Sao Paulo State University, Rio Claro, Brazil.
Res Sports Med. 2008;16(4):244-56. doi: 10.1080/15438620802310800.
The aim of this study was to determine the time to restore the biceps brachii (BB) electromyographic (EMG) activity after the biceps curl (BC) exercise, at different intensities. Ten males performed initially maximal voluntary isometric contractions (MVC) of the elbow flexors, followed by one isometric submaximal contraction at 50% MVC (reference contraction). After this, four bouts of the BC at 25%, 30%, 35%, and 40% 1 RM during 1 minute (randomly assigned, with 10 minutes rest between them) were performed. During the rest intervals at preestablished moments (15 seconds, 1, 3, 5, and 10 min), isometric 50% MVC were performed. The EMG variables (root mean square [RMS], zero crossings [ZC], median frequency, [MF] and peak power [PP]) at rest were compared with reference values. Immediately after the exercise, RMS and PP increased, while ZC and MF decreased, indicating fatigue. After 1 minute most of the variables were similar to the reference. Different load levels did not affect the EMG recovery. In conclusion, the EMG variables recovered after 1 minute rest, indicating the optimal muscular condition for subsequent bouts.
本研究的目的是确定在不同强度的二头肌弯举（BC）运动后，肱二头肌（BB）肌电图（EMG）活动恢复的时间。10名男性首先进行了肘关节屈肌的最大自主等长收缩（MVC），随后进行了一次50%MVC的等长次最大收缩（参考收缩）。在此之后，在1分钟内进行了4组25%、30%、35%和40%1RM的BC运动（随机分配，每组之间休息10分钟）。在预先设定的时刻（15秒、1、3、5和10分钟）的休息间隔期间，进行了50%MVC的等长收缩。将休息时的EMG变量（均方根[RMS]、过零次数[ZC]、中位数频率[MF]和峰值功率[PP]）与参考值进行比较。运动后立即出现RMS和PP增加，而ZC和MF降低，表明出现疲劳。休息1分钟后，大多数变量与参考值相似。不同的负荷水平并未影响EMG的恢复。总之，休息1分钟后EMG变量恢复，表明为后续运动提供了最佳的肌肉状态。
