Lactic threshold vs ventilatory threshold during a ramp test on a cycle ergometer.

OBJECTIVE: The purpose of this investigation was to study the relationship between the lactate (LT) and the ventilatory threshold (VT) during a ramp protocol in cycle ergometry. PARTICIPANTS: Thirty nine trained male subjects were selected as subjects. EXPERIMENTAL DESIGN: All the subjects performed a maximal ergometric test on a cycle ergometer consisting of a ramp protocol (increases of 25 W.min-1). The anaerobic threshold (AT) was determined using both ventilatory gas analysis (VT) and lactate measurement (LT). All the data related to the VT and LT were expressed in work rate (W), VO2 (ml.kg-1.min-1) and heart rate (bpm) and expressed as mean and standard deviation. Lactate threshold (LT) and ventilatory threshold (VT) were compared using the Student's "t"-test for paired data. Correlation coefficients between both variables were also calculated. Statistical significance was accepted at the 5% level. RESULTS: Results showed significant differences (p < 0.05) between mean values of VT and LT when both expressed either as heart rate (bpm), work rate (W), or VO2 (ml.kg-1.min-1). CONCLUSIONS: It was concluded that LT and VT occur at different exercise intensities during ramp protocol exercise on a cycle ergometer.