Ventilatory Threshold Measurement to Evaluate Maximal Endurance Performance

Abstract

The ventilatory (anaerobic) threshold during short-term exercise has been defined as the O₂ uptake (V̇O₂) immediately below the V̇O₂ at which pulmonary ventilation (V̇_E) increases disproportionally relative to V̇O₂ and the ventilatory threshold for long-term exercise as the V̇O₂ immediately below the VO₂ at which the V̇_E continues to increase with time rather than attain a steady state. Maximal endurance performance was determined by measurement of the maximal endurance time during treadmill runs at 90%, and 70% of the previously determined V̇O₂max. The purpose of the present study was to investigate how maximal endurance performance was related to both ventilatory thresholds and to V̇O₂max, and to select which variable best explained maximal endurance performance. The subjects were 11 healthy males. Maximal endurance performance was significantly correlated with the ventilatory threshold for long-term exercise and V̇O₂max. A stepwise multiple regression analysis indicated that maximal endurance performance was best predicted by the ventilatory threshold for long-term exercise. Combination of variables could not improve the prediction. It is concluded that the ventilatory threshold for long-term exercise better explains maximal endurance performance than V̇O₂max or the ventilatory threshold during short-term exercise.

Key words

Anaerobic threshold - endurance performance - maximum oxygen uptake - gas exchange