Theurel Jean, Lepers Romuald, Pardon Laurent, Maffiuletti Nicola A
INSERM ERM 207 Laboratory, Faculty of Sport Sciences, University of Burgundy, BP 27877, 21078 Dijon, France.
Respir Physiol Neurobiol. 2007 Aug 1;157(2-3):341-7. doi: 10.1016/j.resp.2006.12.002. Epub 2006 Dec 15.
The aim of this study was to compare respiratory gas exchange variables and muscle fatigue between equal-intensity (i.e., same force output) electrostimulated and voluntary contractions of the quadriceps muscle (46+/-10% of maximal voluntary force). Twelve healthy men served as volunteers. Oxygen consumption, ventilation and respiratory exchange ratio were recorded during the exercise bouts. Muscle fatigue was quantified as the exercise-induced reduction in maximal voluntary force. The average oxygen consumption (11+/-3 versus 8+/-2 mL min(-1)kg(-1)), ventilation (23+/-4 versus 16+/-2 L min(-1)) and respiratory exchange ratio (0.96+/-0.02 versus 0.85+/-0.01) were significantly higher during electrostimulation compared with voluntary exercise (P<0.05-0.001). Maximal voluntary force decreased significantly after electrostimulation (-21+/-10%; P<0.001), while no changes were observed following voluntary exercise. Electrostimulation-resistance exercise of the quadriceps muscle elicited greater cardiorespiratory demand and muscle fatigue compared with voluntary contractions of the same intensity. These findings probably reflect differences in the patterns of motor unit recruitment between stimulated and voluntary contractions, despite equal force productions.
本研究的目的是比较股四头肌等强度（即相同力量输出）电刺激收缩与自主收缩（最大自主力量的46±10%）之间的呼吸气体交换变量和肌肉疲劳情况。12名健康男性作为志愿者。在运动期间记录耗氧量、通气量和呼吸交换率。肌肉疲劳通过运动诱导的最大自主力量下降来量化。与自主运动相比，电刺激期间的平均耗氧量（11±3对8±2 mL·min⁻¹·kg⁻¹）、通气量（23±4对16±2 L·min⁻¹）和呼吸交换率（0.96±0.02对0.85±0.01）显著更高（P<0.05 - 0.001）。电刺激后最大自主力量显著下降（-21±10%；P<0.001），而自主运动后未观察到变化。与相同强度的自主收缩相比，股四头肌的电刺激抗阻运动引起更大的心肺需求和肌肉疲劳。尽管力量产生相同，但这些发现可能反映了刺激收缩和自主收缩之间运动单位募集模式的差异。
