Is ventilatory anaerobic threshold a good index of endurance capacity?
This study was undertaken to assess whether ventilatory anaerobic threshold (T vent) reflected endurance capacity (EC) in sports medical control. Fifteen subjects performed two cycle ergometer tests. The first was a maximal exercise test, which consisted of increasing the load 20 W/min until exhaustion. During this test, the gas exchange anaerobic threshold was determined and VO2 max was measured. The second was an endurance exercise test, which consisted of asking the subject to work, as long as possible, a load representing 80% of his maximal aerobic power. During this test, we measured endurance time (ET). The statistical analysis showed the lack of relationship between VO2 max and ET and the linear correlations between VO2 T vent ml/min/kg and ET min (r = 0.521, P less than 0.05), VO2 T vent l/min and ET min (r = 0.524, P less than 0.05), and T vent % VO2 max and ET (r = 0.738, P less than 0.01). These results establish that ventilatory anaerobic threshold actually reflects endurance capacity. This relation can be explained referring to the muscle energetic metabolism during exercise. Therefore, T vent should be determined systematically in addition to VO2 max during maximal exercise tests to better evaluate physical fitness.