The Perceptual Responses to Continuous vs Intermittent Blood Flow Restriction Resistance Exercise

Abstract

PURPOSE: To investigate the perceptual responses (ratings of perceived exertion [RPE] and discomfort [RD]) to continuous and intermittent resistance exercise (RE) with blood flow restriction (BFR; 50% of total occlusion pressure), as well as to compare these responses to high- and low-load RE without BFR. METHODS: Fifteen untrained participants were randomly assigned to 4 RE conditions: 1) low-load with continuous BFR (cBFR: cuffs remain inflated between sets); 2) low-load with intermittent BFR (iBFR: cuffs are deflated between sets); 3) low-load without BFR (LI); and 4) high-load without BFR (HI). For all low-load conditions, participants performed 4 sets (30-15-15-15 reps) of bilateral leg press and knee extension at 20% of 1RM, whereas the HI condition involved 4 sets (10-10-10-10 reps) at 70% of 1RM for the same exercises. RPE was assessed after each set using the OMNI-RES scale with scores ranging from 0 to 10. RD was assessed before exercises and after each set using a visual analog pain scale with scores ranging from 0 to 10. Data were analyzed using the Friedman’s and the Wilcoxon tests with Bonferroni correction and p set at 0.05. RESULTS: There were no significant (p>0.05) differences in RPE after each set of leg press for the cBFR and iBFR conditions. HI was significantly (p<0.05) greater than all low-load conditions after each set except for cBFR at sets 1 and 2. There were no significant differences (p>0.05) in RD after each set of the cBFR, iBFR, and HI conditions, except after set 4, when HI was significantly (p<0.05) greater than iBFR. For knee extension, similar responses were observed for RPE after each set, with no significant differences (p>0.05) observed for cBFR, iBFR, and LI conditions; however, HI was significantly (p<0.05) greater than the other 3 conditions. For the HI condition, RD was significantly (p<0.05) greater than the iBFR condition at baseline. Similar RD values were observed for the cBFR, iBFR, and HI conditions after each set, which was significantly (p<0.05) greater than the LI condition. CONCLUSION: Continuous and intermittent RE with BFR seem to elicit similar perceptual responses. For RPE, these responses were similar to those from low-load RE and lower than those from high-load. For RD, both BFR conditions were similar to high-load levels and greater than the low-load condition.