Heart rate and ratings of perceived exertion at the physical working capacity at the heart rate threshold.

The purpose of this investigation was to examine the heart rate (HR) responses and ratings of perceived exertion (RPE) during continuous work bouts at 80, 100, and 120% of the physical working capacity at the heart rate threshold (PWCHRT). Ten men (mean age +/- SD = 23.3 +/- 2.9 years) performed a maximal cycle ergometer test and four, 8-minute submaximal work bouts for the determination of PWCHRT. Each subject then performed 3 continuous 1-hour work bouts at 80, 100, and 120% of the power output corresponding to PWCHRT. The results of the 1-hour work bouts showed that slope coefficients for the mean HR vs. time relationships for all 3 power outputs were significantly (p < 0.05) greater than zero and 0.1 bpm x min(-1). In addition, the slope coefficients for mean RPE vs. time relationships for all 3 power outputs were significantly (p < 0.05) greater than zero. The mean slope coefficients for the HR and RPE vs. time relationships indicated that the PWCHRT test overestimated the maximal power output associated with steady-state HR and RPE responses. The mean HR slope coefficient suggested, however, that the PWCHRT could be maintained for over 4 hours.