Universidade de Brasília (UnB), Brasília, DF, Brazil.
J Electromyogr Kinesiol. 2013 Oct;23(5):1090-6. doi: 10.1016/j.jelekin.2013.04.010. Epub 2013 Jun 3.
Preload of antagonist muscles can be achieved by reciprocal actions (RAs) or by opposing muscle actions. However, evidence concerning neuromuscular and fatigue responses are scarce.
To compare the effects of different knee flexor (KF) preload methods on knee extension (KE) vastus medialis muscle fatigue, based on EMG-spectral index (FI), load range (LR), total work (TW), blood lactate (LAC) and biceps femoris co-activation (BFc) during resistance exercise.
Twenty-four healthy men (23.5±3.6yrs) performed three antagonist pre-load isokinetic exercises (4 sets, 10 repetitions, 60°s(-1), 1min rest between sets): RA (KF contraction immediately followed by KE); Superset (SS; one KF set immediately followed by one KE set); Multiple Set (MS; four KF sets followed by four KE sets).
Total work was significantly greater in RA. There was no significant decrease in LR between sets in RA. The BFc did not differ between protocols (p=0.063). However, RA presented greater biceps femoriscoactivation. The FI was greater during SS compared to RA and MS (p<0.05). The SS had greater LAC when compared to MS and RA (p=0.005 and p=0.007, respectively).
It is suggested that the RA protocol is more neuromuscular and metabolic efficient during the performance of knee extension resistance exercise.
拮抗剂肌肉的预加载可以通过交互作用（RAs）或拮抗肌肉作用来实现。然而，关于神经肌肉和疲劳反应的证据很少。
比较不同膝关节屈肌（KF）预加载方法对膝关节伸展（KE）股直肌疲劳的影响，基于肌电图-频谱指数（FI）、负荷范围（LR）、总功（TW）、血乳酸（LAC）和股二头肌协同激活（BFc）在抗阻运动中的作用。
24 名健康男性（23.5±3.6 岁）进行了三种拮抗剂预加载等速运动（4 组，每组 10 次，60°s(-1)，每组之间休息 1 分钟）：交互作用（KF 收缩后立即进行 KE）；超级组（SS；一组 KF 收缩后立即进行一组 KE 收缩）；多组（MS；4 组 KF 收缩后紧接着 4 组 KE 收缩）。
RA 组总功明显增大。RA 组各次间 LR 无明显下降。各组间 BFc 无差异（p=0.063）。然而，RA 组的股二头肌协同收缩更大。与 RA 和 MS 相比，SS 时 FI 更大（p<0.05）。与 MS 和 RA 相比，SS 的 LAC 更大（p=0.005 和 p=0.007）。
在进行膝关节伸展抗阻运动时，RA 方案在神经肌肉和代谢效率方面更具优势。
