Circulatory readjustment to increased muscle groups exercising statically.

本研究的目的是确定在统计上不同肢体收缩肌肉同时工作时调节循环系统重新调整的生理机制。研究了运动女性在单独静态握力运动(H)或足底屈曲运动(P)期间肱动脉和股动脉血流量、血压、皮肤血流量和肌肉氧含量，并将这两种运动结合起来。在15%、30%和45% MVC强度的静态H或P运动中，由于血压升高，血流量增加。但随着运动强度的增加，活动肌氧饱和度降低，运动后充血增强，提示供氧不足。在组合运动中，包括30% MVC的P运动和15% MVC或45%MVC的H运动，当H运动为45%MVC时，血压、股动脉血流量显著增加，而15% MVC时则没有。皮肤血流量没有明显变化。股动脉导度变化不明显，因此，45% MVC下P + H联合运动时腿部血流量增加可能是由于血压升高所致。尽管腿部血流量增加，但近红外光谱测量的小腿肌肉（腓肠肌内侧）氧合与单独运动时相比没有显著差异。这些结果表明，在联合运动中增加的血流量并没有增加肌肉对氧气的利用。

The aim of this study was to determine the physiological mechanism whic regulated a readjustment of circulatory system, when statistically contracting muscles of different limbs worked simultaneously. Brachial arterial and femoral arterial blood flow, blood pressure, skin blood flow and muscle oxygen ation were studied during the isolated static handgrip exercise (H) or plantar flexion (P), and combined both exercises in active women. During static H or P exercise at the intensities of 15%, 30% and 45% MVC,the blood flow increased due to the elevated blood pressure. However, the active muscle oxygen saturation decreased with the increase in exercise intensity and the post-exercise hyperaemia was augmented, suggesting the insufficiency of the oxygen supply. During combined exercises, which comprised P exercise at 30% MVC and H exercise either at 15% MVC or 45% MVC,the blood pressure, femoral arterial blood flow increased significantly when H exercise was 45%MVC,but not 15% MVC.The skin blood flow did not change significantly. The femoral artery conductance did not change significantly, therefore, the increased leg blood flow during combined P exercise with H exercise at 45% MVC will be attributable to the elevated blood pressure. Despite the leg blood flow increase, the calf muscle (medial gastrocnemius) oxygenation measured by near-infrared spectroscopy did not differ significantly compared to those during isolated exercise. These results suggest that the increased blood flow during combined exercise did not contribute to increase oxygen utilization of the muscle.