Dynamics of Perceived Exertion in Constant-Power Cycling: Time- and Workload-Dependent Thresholds.

Purpose: The purpose of this study was to test the dynamics of perceived exertion shifts (PES) as a function of time and workload during constant-power cycling. Method: Fifty-two participants assigned to 4 groups performed a cycling task at 4 different constant workloads corresponding to their individual rates of perceived exertion (RPEs = 13, 15, 17, and 19, respectively). PES (“increased”/“decreased” perceptions) without magnitude were reported when they occurred. PES “increased” percentages in different nonoverlapping temporal windows and for each workload were calculated to study the time- and workload-dependent relations, respectively. Results: A fluctuating PES dynamic characterized the cycling at RPE-13 and RPE-15. In contrast, a nonfluctuating PES dynamic characterized the cycling at RPE-17 and RPE-19. A time-dependent PES threshold, manifested as a switch from PES fluctuating to nonfluctuating dynamics, emerged in the RPE-15 condition near volitional exhaustion. A workload-dependent PES threshold...