Effects of respiratory muscle work on exercise performance
Effects of respiratory muscle work on exercise performance
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DOI：
10.1152/jappl.2000.89.1.131
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发表时间：
2000-07-01
影响因子：
3.3
通讯作者：
Dempsey, JA
中科院分区：
文献类型：
--
作者：
Harms, CA;Wetter, TJ;Dempsey, JA
最大运动时正常的呼吸肌努力需要心输出量的很大一部分，并导致腿部血流量下降。我们质疑在剧烈运动中经历的高水平呼吸肌工作是否会影响表现。7名男性自行车运动员[最大O-2消耗量（（V）重叠O-2）63 +/- 5 ml。kg（-1）min（-1）]，每个人都在自行车测力计上完成了11项随机试验，其工作负荷要求90%最大（V）超过点O-2。呼吸肌功减少（卸载）、增加（加载）或不变（对照）。与对照组相比，在76%的试验中，随着卸载，到耗尽的时间平均增加1.3 +/- 0.4分钟或14 +/- 5%，而在83%的试验中，随着负载，到耗尽的时间平均减少1.0 +/- 0.6分钟或15 +/- 3%（P < 0.05）。运动过程中呼吸肌负荷降低（V）过dor O-2引起的过度换气，并降低了整个运动过程中呼吸和肢体不适感的变化率。这些发现表明，在持续的，高强度的I运动（90%（V）超过点O-2）的呼吸正常发生的工作对运动表现有显着的影响。我们推测，这种正常的呼吸肌负荷对训练有素的男性自行车运动员的性能的影响是由于腿部血流量的相关减少，这增强了腿部疲劳的发作和腿部和呼吸肌的努力被认为是强度。
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.