Limiting factors for maximum oxygen uptake and determinants of endurance performance
Limiting factors for maximum oxygen uptake and determinants of endurance performance
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DOI：
10.1097/00005768-200001000-00012
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发表时间：
2000-01-01
期刊：
影响因子：
--
通讯作者：
Howley, ET
中科院分区：
文献类型：
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作者：
Bassett, DR;Howley, ET
在运动人体中，最大摄氧量((V)超过点O-2max)受到心肺系统向运动肌肉输送氧气的能力的限制。这主要表现在三条证据上：1)当氧输送被改变(通过血液兴奋剂、缺氧或β-阻断)时，(V)超过点O-2max相应地改变；2)随着训练，(V)超过点O-2max的增加主要是由于最大心输出量的增加(而不是a-(V)相对于BAR O-2差的增加)；以及3)当运动中小肌肉块被过度灌流时，它具有极高的耗氧能力。因此，在锻炼中，氧-2输送而不是骨骼肌氧-2提取被视为比点氧-2max更重要的限制因素。然而，骨骼肌中的代谢适应对于提高亚最大耐力成绩至关重要。耐力训练导致线粒体酶活性的增加，这通过加强FAR氧化和减少在给定(V)的点O-2上的乳酸积累来改善运动成绩。(V)Over Dot O-2max是设定耐力成绩上限的一个重要变量(皮肤黝黑的运动员在长时间内Over Dot O-2max不能超过100%(V))。运行经济性和(V)在点O-2max上的分数利用也影响耐力性能。乳酸阈值速度(LT)综合了所有这三个变量，是预测长跑成绩的最佳生理指标。
In the exercising human, maximal oxygen uptake ((V) over dot O-2max) is limited by the ability of the cardiorespiratory system to deliver oxygen to the exercising muscles. This is shown by three major lines of evidence: 1) when oxygen delivery is altered (by blood doping, hypoxia, or beta-blockade), (V) over dot O-2max changes accordingly; 2) the increase in (V) over dot O-2max with training results primarily from an increase in maximal cardiac output (not an increase in the a-(v) over bar O-2 difference); and 3) when a small muscle mass is overperfused during exercise, it has an extremely high capacity for consuming oxygen. Thus, O-2 delivery, not skeletal muscle O-2 extraction, is viewed as the primary limiting factor fur (V) over dot O-2max in exercising humans. Metabolic adaptations in skeletal muscle are, however, critical for improving submaximal endurance performance. Endurance training causes an increase in mitochondrial enzyme activities, which improves performance by enhancing far oxidation and decreasing lactic acid accumulation at a given (V) over dot O-2. (V) over dot O-2max is an important variable that sets the upper limit for endurance performance tan athlete cannot operate above 100% (V) over dot O-2max, for extended periods). Running economy and fractional utilization of (V) over dot O-2max also affect endurance performance. The speed at lactate threshold (LT) integrates all three of these variables and is the best physiological predictor of distance running performance.