Samii A, Wassermann E M, Hallett M
Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1428, USA.
Electroencephalogr Clin Neurophysiol. 1997 Oct;105(5):352-6. doi: 10.1016/s0924-980x(97)00033-7.
Post-exercise facilitation and post-exercise depression are phenomena described in motor evoked potentials (MEPs) elicited to transcranial magnetic stimulation. Brief, non-fatiguing muscle activation produces post-exercise facilitation, and prolonged fatiguing muscle activation produces post-exercise depression. We studied 12 normal subjects to determine whether post-exercise depression occurs before fatigue is reached. We recorded MEPs from the resting extensor carpi radialis muscle after increasing the duration of isometric wrist extension, at 50% of maximum voluntary contraction, until the muscle fatigued. Fatigue was defined as the inability to maintain that force. The mean exercise duration before the muscle fatigued was 130 s, and post-exercise depression occurred only beyond 90 s of exercise. We conclude that post-exercise depression is detectable only after prolonged muscle activation.
运动后易化和运动后抑制是经颅磁刺激诱发的运动诱发电位（MEP）中描述的现象。短暂的、非疲劳性肌肉激活会产生运动后易化，而长时间的疲劳性肌肉激活会产生运动后抑制。我们研究了12名正常受试者，以确定运动后抑制是否在达到疲劳之前就已发生。我们在以最大自主收缩的50%进行等长腕伸展，增加其持续时间直至肌肉疲劳后，记录了静息状态下桡侧腕伸肌的MEP。疲劳定义为无法维持该力量。肌肉疲劳前的平均运动持续时间为130秒，运动后抑制仅在运动90秒后出现。我们得出结论，运动后抑制只有在长时间肌肉激活后才能检测到。
