The rating of perceived exertion is not different at the ventilatory threshold in sedentary women with different body mass indices

Abstract

The ventilatory threshold (VT), or respiratory compensation point, is an important respiratory-metabolic marker of aerobic fitness. Exercise at VT intensity provides an optimal stimulus for body mass loss and improvement in aerobic fitness. The use of ratings of perceived exertion (RPE) to self-regulate exercise intensity is more feasible than prescribing exercise using oxygen consumption (V˙O2) and heart rate (HR). Identifying RPE at the VT (RPEVT) is an optimal intensity target for perceptually regulated exercise. The aim of this study was to compare the RPEVT among normal body mass, overweight, and obese sedentary women, according to body mass index (BMI). Each participant performed a maximal graded treadmill test, where RPE, pulmonary ventilation, V˙O2, carbon dioxide output, and HR were monitored, and VT was determined. The RPEVT was identified as the RPE estimated during the minute the VT occurred. V˙O2, percentage of maximal V˙O2 (%V˙O2max), and percentage of maximal HR (%HRmax) at the VT and RPEVT were compared among groups using analysis of variance. Obese women exhibited lower V˙O2 , %V˙O2max, and %HRmax at the VT than other groups, with no differences between normal and overweight women. However, RPEVT was similar among groups. In summary, RPEVT was approximately 12 in sedentary women, regardless of BMI classification.