Similarity in physiological and perceived exertion responses to exercise at continuous and intermittent critical power

The purpose of this study was to compare the physiological responses [oxygen uptake (VO2), heart rate (HR) and blood lactate concentrations ([BLa])] and the rating of perceived exertion (RPE) response until exhaustion (TTE) at the continuous (CPc) and intermittent (CPi) critical power workloads. Ten moderately active men (25.5 ± 4.2 years, 74.1 ± 8.0 kg, 177.6 ± 4.9 cm) participated in this study. The incremental test was applied to determine the highest values of oxygen uptake (VO2max), heart rate (HRmax), blood lactate concentrations ([BLamax]), and maximal aerobic power (MAP). Continuous and intermittent exhaustive predictive trials were performed randomly. The hyperbolic relation between power and time was used to estimate CPc and CPi. CPi was derived from predictive trial results at an effort and recovery ratio of 30:30 s. Exercise at CPc and CPi as well as the physiological and RPE responses were measured until exhaustion. The values of physiological variables during CPc and CPi did not differ in either TTE test and were lower than the VO2max, HRmax and [BLamax] values. RPE was maximal at the end of exercise at CPc and CPi. There was a high correlation between VO2max (L min−1) and CPc and CPi intensities (r ≥ 0.90) and between MAP, CPc and CPi (r ≥ 0.95). Similar physiological and RPE responses were found at CPc and CPi for the times analyzed.