RESUMO
AIM: The purpose of this study was to compare hemodynamic responses during low-intensity resistance exercise, with (LI-BFR) and without (LI) blood flow restriction, with high-intensity resistance exercise (HI). METHODS: In a randomized crossover design, 17 healthy subjects performed 3 sets (15 repetitions, 20% 1RM, 45-second rest interval between sets) of 45° bilateral leg press exercises for the LI-BFR and LI protocols; and 3 sets (8 repetitions; 80% 1RM; 1-minute rest interval between sets) for the HI protocol. The BFR was established using two sphygmomanometers (18x90 cm) inflated to partially occlude blood flow to the femoral artery. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) were evaluated continuously and noninvasively by beat-to-beat measurements during each protocol. RESULTS: Significantly smaller values were demonstrated during the LI-BFR session versus the HI session between the first and second sets for SBP; during the first, second and third sets for DBP; during the first set for HR; during the first, second and third sets for SV; during the first set for CO, and during the second set for TPR. Conversely, perceived exertion was significantly higher in the LI-BFR session versus the HI session. CONCLUSION: The LI-BFR session was associated with significantly reduced cardiovascular responses versus the HI session, but showed higher values of subjective perceived exertion.