正常和低氧环境下递增负荷运动时通气阈、乳酸阈的变化

Changes of ventilation threshold and lactic acid threshold during load gradually increased exercising in normal and hypoxic environments

通过测试10名体育专业学生在正常与模拟1 000、1 500 m低氧环境下进行递增负荷运动中气体代谢、血乳酸等指标变化,观察低氧对机体乳酸阈和通气阈的影响。结果显示:1)三种环境下,通气阈分别是:(720.0±71.8)s、(631.1±60.1)s、(616.0±40.0)s;乳酸阈时间是(826.67±72.11)s、(816.00±94.66)s、(744.00±94.66)s。2)随着氧分压的降低,通气阈均早于乳酸阈出现,通气阈和乳酸阈时各指标的绝对值下降,但其百分比值变化不大。3)正常环境下,乳酸阈和通气阈的相关性系数r>0.65(P<0.05),但模拟1 000 m与模拟1 500 m相关性系数r<0.60(P>0.05)。结论:1)通气阈和乳酸阈的指标及其百分比值可以用来衡量或评价运动训练效果、指导运动训练;2)进入较高海拔后,应适当调整运动强度,以适应环境的变化。

By measuring the changes of such indexes as gas metabolism and blood lactic acid of 10 students majoring in physical education during load gradually increased exercising in normal and simulated 1,000m and 1,500m hypoxic environments, the authors observed the effects of hypoxia on the body＇s lactic acid threshold and ventilation threshold, and revealed the following findings： 1） in the three environments, the ventilation thresholds are （720.0±71.8） s, （631.1±60.1） s and （616.0±40） s respectively; the lactic acid threshold times are （826.67±72.11） s, （816.00±94.66） s and （744.00±94.66） s; 2） with the decrease of partial oxygen pressure, the ventilation threshold appeared earlier than the lactic acid threshold, and the absolute value of such indexes as ventilation threshold and lactic acid threshold decreased, but their percentage changed little; 3） in a normal environment, the coefficient of correlation between lactic acid threshold and ventilation threshold r〉0.65（P〈0,05）, but in simulated 1,000m and 1,500m hypoxic environments, r〈0.60（P〉0.05）. Conclusions： 1） such indexes as ventilation threshold and lactic acid threshold as well as their percentage can be used to measure or evaluate sports training effects and to guide sports training; 2） for training in a place at a higher altitude, the exercise intensity should be appropriately adjusted, so that the athletes can adapt to the change of environment.