A comparison between ventilation and heart rate as an indicator of oxygen uptake during physical activities of different intensities

Abstract : The aim of this study is to compare the relation between ventila-tion (VE) and oxygen uptake (VO2) [VO2=f (VE)] and between heart rate (HR) and VO2 [VO2=f (HR)]. Each one of the subjects performed three types of activities of different intensities (walk-ing without load, walking with load and intermittent work). VO2, VEand HR were measured continuously by using indirect calorimetry and an electrocardiogram. Linear regressions and coefficients of determination (râ²) were calculated to compare the relation VO2 = f (VE) and VO2 = f (HR) for two different regroupings: by session duration (râ²session) and by subject (râ²subject). Results showed that râ²session of the relation VO2 = f (VE) were significantly higher than those of the relation VO2 = f (HR) for steady state activities (walking with or without load during 3 or 6 min, p