Cardiac and Hemodynamic Responses to Resistance Training Sessions with and Without Blood Flow Restriction Performed to Muscular Failure

This study investigated the acute cardiac and hemodynamic responses to high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and low-intensity resistance training with blood flow restriction (LIRT+BFR) during sessions composed of sequential exercises performed to muscular failure. Fourteen resistance-trained men (age: 21.8 ± 1.7 years; height: 178.3 ± 8.3 cm; body mass: 76.0 ± 8.1 kg) completed a repeated-measures crossover design in which each participant performed all three experimental conditions in a fixed, non-randomized order: HIRT (four sets at 70% 1RM), LIRT (four sets at 30% 1RM), and LIRT+BFR (four sets at 30% 1RM with a fixed cuff pressure of 80 mmHg), all executed in repetition-to-failure mode. Heart rate (HR), rate–pressure product (RPP), systolic blood pressure (SBP), mean arterial pressure (MAP), and diastolic blood pressure (DBP) were measured at rest, immediately after each session, and 30 min post-exercise. At the end of the sessions, HIRT, LIRT, and LIRT+BFR all showed significant increases in HR, RPP, SBP, MAP, and DBP compared with resting values (p < 0.01), with no differences between protocols. Delta values (pre–post changes) were similar across protocols. Post-exercise, HR and RPP remained elevated compared with baseline in all protocols (p < 0.01), with no differences between them. SBP and MAP were reduced when compared with rest at 30 min post-exercise in HIRT, LIRT, and LIRT+BFR (p < 0.05), with no differences among protocols. For DBP, only LI showed a reduction compared with the rest (p < 0.01); however, LIRT+BFR values were significantly higher than HIRT (p < 0.01) and LIRT (p < 0.01). No statistically significant between-protocol differences were observed for the immediate post-exercise cardiac and hemodynamic responses under the conditions investigated.