A Physiological Anchor for the Perception of Effort.

This is a two-part study to determine one or more reliable physiological anchors for perception of effort. The purpose of Study 1 was to compare ratings of perceived exertion (RPE) at the ventilatory threshold (VT) in running, cycling, and upper body exercise with the premise that if RPE at VT did not differ across exercise modes, VT might provide a unique set of physiological inputs for perception of effort. For 27 participants, values for VT and for RPE at VT (Borg 6 to 20 scale) averaged 9.4 km⋅h ( = 0.7) and 11.9 km⋅h ( = 1.4) respectively in running, 135 W ( = 24) and 12.1 W ( = 1.6) in cycling, and 46 W ( = 5) and 12.0 W ( 1.7) in upper body exercise. RPE did not differ, suggesting that VT may anchor effort perception. In Study 2, 10 participants performed cycle ergometer exercise for 30 minutes at their VT ( = 101 W, 21), at their maximal lactate steady state ( = 143 W, = 22), and at their critical power (CP; = 167 W, = 23). Mean end-exercise RPE were 12.1 ( = 2.1), 15.0 ( = 1.9), and 19.0 ( = 0.5), respectively. The very close clustering of RPE during exercise at CP hints that the confluence of physiological responses at CP may (also) serve as a determinant in perception of effort.