Are there perceptual differences to varying levels of blood flow restriction?
The application of blood flow restriction (BFR) with low load exercise has been shown to produce favorable muscle and vascular adaptations. Given the potential clinical utility of BFR, it is important to characterize the ratings of perceived exertion (RPE) and discomfort across a variety of relative pressures as the individual's perceptual response may ultimately dictate whether a participant continues with this modality of exercise. Fourteen participants completed 3 days of exercise. Conditions included unilateral elbow flexion with six pressures ranging from 40% to 90% arterial occlusion at 30% of their one repetition maximum (1RM). Differences in RPE (6: no exertion at all, 20: maximal exertion) were found across conditions for set 2 (range of 13-15), 3 (range of 15-16), and 4 (range of 15-17). Following Bonferroni adjustments, none were significant. Differences in discomfort (0: no discomfort at all; 10: maximum discomfort) were found across conditions for set 1 (range of 2-3), 2 (range of 3.2-5), 3 (range of 4-6.5), and 4 (range of 5-7). Post-hoc analyses only found differences within set 3. Although it is presently unknown if higher pressures are required for optimal adaption of tissues other than skeletal muscle, our results suggest that the perceptual rating during exercise is unlikely to be a limiting factor in the application of higher pressures.