Estimation of the exercise ventilatory compensation point by the analysis of the relationship between minute ventilation and heart rate.

Cardiopulmonary exercise test is the gold standard for the identification of the ventilatory compensation point (VCP), an important threshold for exercise training prescription. We hypothesized that changes in the slope of increment in minute ventilation (V'(E)) over heart rate (HR) during incremental exercise can be utilized, as alternative to the ventilatory equivalents method, for VCP detection. In 14 healthy subjects (ten males, four females, age 31 +/- 10 SD) we studied the ventilatory, cardiovascular and gas exchange adaptations during two incremental cycle ergometer exercise: (F) fast work rate increments (30-20 watt/min, M-F), (S) slow work rate increments (15-10 watt/min, M-F). A good between-method agreement in VCP detection in terms of oxygen uptake (V'O(2)) was found in both F and S protocols (F: -7 +/- 118 V'O(2) ml/min; S: -36 +/- 144 V'O(2) ml/min). VCP occurred at the same percentage of peak V'O(2) in both protocols. The changes in the V'(E) versus HR slope during incremental exercise can be used to detect the VCP as alternative to the ventilatory equivalents method.