期刊
JOURNAL OF APPLIED PHYSIOLOGY
卷 89, 期 1, 页码 131-138出版社
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/jappl.2000.89.1.131
关键词
blood flow distribution; dyspnea; work of breathing
资金
- NHLBI NIH HHS [R01 HL-15469] Funding Source: Medline
The normal respiratory muscle effort at maximal exercise requires a significant fraction of cardiac output and causes leg blood flow to fall. We questioned whether the high levels of respiratory muscle work experienced in heavy exercise would affect performance. Seven male cyclists [maximal O-2 consumption ((V) overdot O-2) 63 +/- 5 ml . kg(-1) min(-1)] each completed 11 randomized trials on a cycle ergometer at a workload requiring 90% maximal (V) over dot O-2. Respiratory muscle work was either decreased (unloading), increased (loading), or unchanged (control). Time to exhaustion was increased with unloading in 76% of the trials by an average of 1.3 +/- 0.4 min or 14 +/- 5% and decreased with loading in 83% of the trials by an average of 1.0 +/- 0.6 min or 15 +/- 3% compared with control (P < 0.05). Respiratory muscle unloading during exercise reduced (V) over dor O-2 caused hyperventilation, and reduced the rate of change in perceptions of respiratory and limb discomfort throughout the duration of exercise. These findings demonstrate that the work of breathing normally incurred during sustained, heavy-intensity I exercise (90% (V) over dot O-2) has a significant influence on exercise performance. We speculate that this effect of the normal respiratory muscle load on performance in trained male cyclists is due to the associated reduction in leg blood flow, which enhances both the onset of leg fatigue and the intensity with which both leg and respiratory muscle efforts are perceived.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据