急性低氧对耐力运动员无氧代谢阈值的影响

EFFECT OF ACUTE HYPOXIA ON ANAEROBIC THRESHOLD IN ENDURANCE ATHLETES

通过观察急性低氧对耐力运动员无氧代谢阈值的影响,探讨了急性低氧对耐力运动员体力活动能力的影响,并分析与上述影响强弱有关的若干可能因素。18名青年耐力运动员分别吸入21％O_2(常氧对照)和12.8％O_2(急性低氧),进行逐级递增体力负荷运动,直至最大耐受量。观察运动期间每分通气量、氧耗量、二氧化碳排出量、动脉血氧饱和度、心率和氧脉搏,并测定无氧代谢阈值。结果表明,急性低氧使耐力运动员的无氧代谢阈值明显降低。各个体无氧代谢阈值的降低程度分别与该个体动脉血氧饱和度以及氧脉搏的降低程度呈正相关。急性低氧下无氧代谢阈值降低提示了体力活动能力的削弱,而低氧下心肺代偿功能较弱以及动脉血氧饱和度较低者,其体力活动能力的削弱较明显。

The effect of acute hypoxia on the anaerobic threshold (AT) of endurance athletes was examined. Eighteen healthy young endurance athletes performed incremental exercise to subjective exhaustion on a bicycle ergometer during normoxia and acute hypoxia (12.8% O2). AT was determined by the gas exchange method of Wasserman. As compared with the normoxic control value (37.8±5.1 ml·kg-1·min-1, Vo2), AT decreased significantly during hypoxia (22.8± 3.4ml·kg-1·min-1, Vo2, p<0.01). The reduction in AT was positively related to the decrease in Sao2 (r = 0.94, p<0.01) and in O2 pulse (r = 0.90, p< 0.05). The decreased AT suggests a decline in physical capacity. It is concluded that AT in endurance athletes reduces during acute hypoxia and the reduction is more obvious in individuals whose cardiopulmonary compensatory function is weaker.