Alterations in aerobic-anaerobic proportions of metabolism during work in heat
Alterations in aerobic-anaerobic proportions of metabolism during work in heat
复制标题
高温工作期间新陈代谢的有氧-无氧比例的变化
DOI：
10.1007/bf00421200
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
B. S. Arora
中科院分区：
文献类型：
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作者：
Goberdhan P Dimri;M. S. Malhotra;J. Sen Gupta;T. Sampath kumar;B. S. Arora
为了研究在不同的热应激条件下，不同级别的肌肉活动中氧气供应的有氧和无氧比例，对六名自然适应热的年轻健康印度人进行了研究。受试者在三种不同的模拟条件下在自行车测力计上进行400、500和600 kgm/min（相当于65.40、81.75和98.10 W）的次极量运动6 min，即，舒适，湿热，非常湿热。分别测定安静时、运动期间（6 min）和运动后30 min的氧耗量（VO 2）、肺通气量（VE）和心率（HR）。在安静和恢复期间测定血乳酸水平（LA）。从这些，总O2成本与好氧和厌氧的比例进行了计算。结果表明，随着热应激的增加，每次运动的总耗氧量显著增加，沿着无氧组分显著增加，有氧组分显著减少。在每一个工作负荷的相对O2债务（l/kg）和血乳酸水平的显着增加进一步证实了在无氧的能源供应过程中的贡献的增加。因此，O2债收缩与热应激增加之间存在高度显著的相关性（P<0.001）。与舒适温度相比，湿热和极湿热条件下的最大摄氧量（VO 2 max）显著下降，而最大心率（HR max）和最大呼气流速（VEmax）无变化。
With a view to investigating the aerobic and anaerobic proportions of oxygen supply during different grades of muscular activity in varying thermal stress, studies have been conducted on six young healthy Indians naturally acclimatized to heat. The subjects were given submaximal exercises of 400, 500, and 600 kgm/min (equivalent to 65.40, 81.75, and 98.10 W) for 6 min on a bicycle ergometer in three different simulated conditions, i.e., comfortable, hot humid, and very hot humid. Their O2consumption (VO2), pulmonary ventilation (VE) and heart rate (HR) were measured during rest and throughout the exercise period (6 min) and for 30 min post exercise. Blood lactate level (LA) was measured during rest and recovery. From these, the total O2cost with aerobic and anaerobic proportions were calculated. Results indicated a significant increase in the total O2cost for each exercise with increasing thermal stress, along with a significant increase in the anaerobic fraction and a decrease in the aerobic fraction. The increase in anaerobic contribution to the energy supply processes was further confirmed by a significant increase in relative O2debt (l/kg) and in blood lactate level at each work load. Thus, a highly significant correlation (P<0.001) was found between O2debt contracted and increase in thermal stress. A significant fall inVO2max was also observed in hot humid and very hot humid conditions as against comfortable temperature, with no change in HR max andVEmax.