Cardiovascular Responses to a Full Resistance Training Session Performed with and Without Blood Flow Restriction

Resistance training (RT) can induce cardiovascular overload, especially at high intensities. Blood flow restriction (BFR) has emerged as a low-load alternative that is potentially effective and safe, although its hemodynamic and respiratory effects remain controversial. Background/Objectives: The aim of this study was to compare cardiovascular responses between a high-load RT session (RT_HL; 70% of one repetition maximum—1RM) and a low-load session combined with BFR (RT_LL+BFR; 30% 1RM). Methods: Nineteen trained men (24.3 ± 3.9 years; 177.7 ± 6.3 cm; 84.7 ± 13.0 kg) performed the RT_HL and RT_LL+BFR protocols, with eight exercises for each protocol. The following variables–heart rate (HR), percentage of maximum heart rate (%HRmax), systolic blood pressure (SBP), diastolic blood pressure (DBP), and rate pressure product (RPP)–were assessed during the protocols. Results: Both protocols significantly increased HR (pre: 74 ± 8 bpm; post: RT_HL = 142 ± 9 bpm; RT_LL+BFR = 133 ± 6 bpm; p < 0.01), %HRmax (RT_HL = 72 ± 5%; RT_LL+BFR = 69 ± 4%; p < 0.01), SBP (RT_HL = 144 ± 6 mmHg; RT_LL+BFR = 140 ± 6 mmHg; p < 0.05), and RPP (RT_HL = 20,469 ± 1620; RT_LL+BFR = 18,637 ± 1253; p < 0.01) compared to resting values. No variable exceeded safety thresholds for RPP (<30,000; %HRmax < 75%), and DPB showed a slight elevation in both conditions (p < 0.05), but without differences between protocols (p = 0.28). Conclusions: Exercise load intensity was an important determinant of hemodynamic responses, but BFR elicited comparable stimuli with low load, thereby emphasizing improved safety to traditional high-load-intensity training.