通气阈、乳酸阈和血气变化的关系

本文通过10名受试者的自身对比,比较了4种判断无氧阈方法的异同,以血气指标评定无氧阈也存在较大的个体差异。因此,作者认为,无氧阈的方法学当前面临的主要问题之一是制定统一的标准。

RELATIONSHIP BETWEEN VENTILATORY THRESHOLD, LACTATE THRESHOLD AND BLOOD GAS

Gas exchange, blood lactate and blood gas were studies during an incremental cxercise test on abicycle ergometer on ten healthy male subjects. Gas exchange was measured breath-by-breath. A tef-lon catheter was inserted precutaneusly into a brachial artery for sampling of arterial blood. Bloodlactate was measured by enzymatic technique. The blood gas parameters (PO_2, PCO_2, pH. HCO_?.-)were analyzed by the Radiometer (Copenhagen). Because of the widespread use of the determinationof the anaerobic threshold (AT), we felt it would be important to compare the values of oxygenuptake and work rate discerned from four criteria: 1. gas exchange break point (ventilatory thresholdVT); 2. lactate break point (lactate threshold LT); 3. 2 mM (lactate); and 4. 4 mM (lactate). The data have shown that there is no significant in oxygen uptake and work rate (P>0.05)whether measured by gas exchange or blood lactate in nine subjectes. Compared to the gas exchangecriteria, work rate occurred by the other three methods was higher by 1.5, 55.5 and 109.5 wattsrespectively; the last two being significantly different (P<0.05). The blood gas parameters, which are used for detection of the AT, have a great individualvariation. Thus, the methodological aspects in the determination of the AT need to be further studied andstandardized.