Brachial arterial blood flow during static handgrip exercise of short duration at varying intensities studied by a Doppler ultrasound method
Brachial arterial blood flow during static handgrip exercise of short duration at varying intensities studied by a Doppler ultrasound method
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DOI：
10.1046/j.1365-201x.1997.00158.x
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发表时间：
1997-07-01
期刊：
影响因子：
--
通讯作者：
Homma, S
中科院分区：
文献类型：
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作者：
Kagaya, A;Homma, S
本研究的目的是确定不同强度静态握柄运动期间前臂血流变化与心率和血压的关系。7名运动妇女在仰卧位以10、30、50和70%最大随意收缩（MVC）强度进行静态握力运动1 min。（多普勒超声方法），根据血管直径、流速和心率计算（通过EGG测量），从运动前对照值（87.5 +/- 14.1 mL min（-1））增加到相似水平（137.3 +/- 20.2 - 160.9 +/- 26.1 mL min（-1））。在较低强度下的这些增加可归因于一个心动周期期间的流入增加，而在较高强度下，它们是由于心率增加。收缩压和舒张压（Finapres）更改从10% MVC增加（16.1 +/- 3.4，9.0 +/- 1.7 mmHg）高达50% MVC（33.8 +/- 6.7，25.0 +/- 4.9 mmHg），但在70% MVC时不成比例地升高（46.1 +/- 7.9，42.9 +/- 8.9 mmHg），表明发生了神经血管收缩。运动后立即充血，作为血液供应不足的指标，随着运动强度的增加而变得更大。这些结果表明，在不同强度的60 s静态握力运动中，通过升高血压和心率，肱动脉血流量维持在相似的水平，这可能抵消了较高运动强度时肌内压的升高和神经血管收缩。运动后充血反应的幅度随着运动水平的增加而增加，尽管在运动期间手臂的血流量增加。这表明，在更高水平的运动中，前臂肌肉中的氧气输送不平衡恶化。
The purpose of this study was to determine forearm blood flow changes during static handgrip exercise at different intensities in relation to heart rate and blood pressure. Seven active women performed static handgrip exercise at intensities of 10, 30, 50 and 70% maximum voluntary contraction (MVC) in a supine position for 1 min. During exercise at different intensities, the brachial arterial blood flow (Doppler ultrasound method), calculated from vessel diameter, flow velocity and heart rate (measured by EGG), increased to a similar level (137.3 +/- 20.2 -160.9 +/- 26.1 mL min(-1)) from pre-exercise control value (87.5 +/- 14.1 mL min(-1)). These increases at the lower intensities were attributable to increased in-flow during one cardiac cycle, whereas at the higher intensities, they were due to increased heart rate. Both systolic and diastolic blood pressure (Finapres) changes increased from 10% MVC (16.1 +/- 3.4, 9.0 +/- 1.7 mmHg) up to 50% MVC (33.8 +/- 6.7, 25.0 +/- 4.9 mmHg), but were disproportionately more elevated at 70% MVC (46.1 +/- 7.9, 42.9 +/- 8.9 mmHg), suggesting neural vasoconstriction had occurred. Immediate post-exercise hyperaemia, used as an indicator of poor blood supply, became greater as the exercise intensity increased. These results suggest that the brachial arterial blood flow was maintained at a similar level during 60-s static handgrip exercise at different intensities by elevating the blood pressure and heart rate, which probably counteracted the increased intramuscular pressure and neural vasoconstriction occurring at the higher exercise intensity. The magnitude of the post-exercise hyperemic response increased as exercise level increased despite increased blood flow to the arm during exercise. This suggests a worsening imbalance in oxygen delivery in forearm muscles at higher levels of exercise.