Prescribing Blood Flow-Restricted Cycling Using Rating of Perceived Exertion Balances the Physiological and Perceptual Demands in Young Healthy Adults

Abstract

To compare the physiological and perceptual responses during fixed-power and perceptually regulated cycling, both without and with blood flow restriction (CON_PWR, BFR_PWR, CON_RPE and BFR_RPE). Twelve recreationally active men cycled for 10 min at the power corresponding to the first ventilatory threshold or, for CON_RPE and BFR_RPE, the perceived exertion level reported during CON_PWR. Blood flow restriction was set at 60% of estimated arterial occlusion pressure. Ventilatory measures and heart rate were averaged into 2-min blocks. Perceived exertion, effort, muscular discomfort and cuff pain were recorded every 2 min (0–10 scale). Blood lactate was measured pre-exercise, post-exercise, and 2 min post-exercise. The BFR_PWR trial elicited greater physiological and perceptual responses compared to all other conditions. Oxygen consumption during BFR_RPE was lower than CON_PWR (−19.2 ± 20.6%, p < 0.001) and CON_RPE (−6.7 ± 9.3%, p = 0.007). Heart rate during CON_PWR was greater than BFR_RPE (8.2 ± 9.8%, p < 0.001) and CON_RPE (9.4 ± 6.5%, p < 0.001). Blood lactate concentration was not different between CON_PWR, CON_RPE and BFR_RPE; yet was greater during fixed-power compared to fixed-RPE trials (31.5 ± 25.6%, p < 0.001). Muscular discomfort was not different between BFR_RPE and CON_PWR (2.4 ± 1.1 au), yet both were greater compared to CON_RPE (1.8 ± 1.5 au, p < 0.001). Cuff pain was greater during BFR_PWR (3.3 ± 1.7 au) compared to BFR_RPE (2.2 ± 1.1 au, p < 0.001). Prescribing aerobic BFR cycling at a fixed power output increases physiological strain, yet discomfort and pain are also heightened, which may limit its use in healthy adults. The fixed-RPE method appears to balance the physiological and perceptual demands and thus could be a viable alternative if a fixed power output approach is intolerable.