Effect of resistance taming on sympathetic nervous function in humans

抗阻训练不仅能增强肌肉力量，还能改善自主控制系统等生理功能。然而，理由或机制尚不清楚。本研究以高强度握力训练作为抗阻训练，探讨抗阻训练对运动中肌肉交感神经活动（MSNA）及心血管反应的影响。单侧（非优势臂）握力训练，包括3组14次10秒的最大自主等长收缩，每周3天，共4周。训练使训练组和非训练组手臂的最大握力增加，并在训练前和训练后观察10次间歇性静态握力15s时的心率和MSNA反应。训练后，心率反应的手柄增加训练手臂的运动，也为未经训练的手臂运动。MSNA增加， 关于我们 g收缩反应的起始时间均早于训练前。这表明，心血管和交感神经反应可能是由于中央命令，这是在更高的大脑中心，而不是肌肉reflex.Effect的阻力训练对肌肉代谢反射的影响进行了测试，在两分钟后运动动脉闭塞，然后节奏的握力为一分钟，在前臂缺血下进行最大的努力。虽然训练前优势臂运动比非优势臂运动时代谢反射MSNA反应更强，但训练后训练臂（非优势臂）的MSNA反应增强，而非训练臂（对照侧）的MSNA反应没有增强，且反应大小在臂间无差异，说明抗阻训练对心率和交感神经系统有很大的影响。这些结果表明，即使在运动过程中参与活动的肌肉量很小，但强烈的运动努力对心血管控制系统也起着重要作用。少

Resistance training develops not only muscular strength but also improving physiological function such as autonomic control system. However, rationale or the mechanisms are not clear. A goal of this project was to investigate how resistance-training influence muscle sympathetic nerve activity (MSNA) and cardiovascular response during exercise.High intensity handgrip exercise was used as resistance training. Unilateral (nondominant arm) handgrip training, which composed 3 set of 14 times of 10-sec maximal voluntary isometric contraction, was performed three days per week for 4 weeks. The training lead to increased maximal handgrip force in trained as well as untrained arm.Heart rate and MSNA response during 10 times intermittent static handgrip for 15 seconds performed with voluntary maximum effort was investigated before and after training. After training heart rate response to the handgrip increased for trained arm exercise and also for untrained arm exercise. MSNA was increased durin … More g contractions of either trained or untrained arm and the onset of the response was earlier than that before training. This suggests that cardiovascular and sympathetic nervous response may be due to central command that was generated in the higher brain center rather than muscle reflex.Effect of resistance training on muscle metaboreflex was tested during two minutes post exercise arterial occlusion followed rhythmic handgrip for one minute performed with maximal effort under the forearm ischemia. Although before training dominant arm exercise had a greater metaboreflex MSNA response than that of nondominant armor The MSNA response for trained arm (nondominant arm), but not untrained arm (control side) enhanced after training, while the size of response was not different between the arms.This study demonstrated that resistance training have great effect on heart rate and sympathetic nervous system. From these results suggest that strong exercise effort even if active muscle mass was small involved during exercise play an important role to cardiovascular control system. Less