Hemodynamic response to resistance exercise with and without blood flow restriction in healthy subjects.

Objective: To compare the hemodynamic response during resistance exercise at high intensity (HI), low intensity (LI) and low intensity with blood flow restriction (LI-BFR) in healthy subjects.

Methods: Twelve men performed three sets of unilateral knee extension exercises at LI-BFR and LI (15 repetitions; 20% of 1RM) and HI (8 repetitions; 80% of 1RM). The blood flow restriction was accomplished using a sphygmomanometer positioned on the thigh and inflated to the point of blood flow interruption (167·9 ± 16·6 mmHg). The hemodynamic variables were obtained by continuous beat-to-beat photoplethysmography. Rating of perceived exertion (RPE) and blood lactate were also measured.

Results: The HI session showed higher values (P<0·05) in all sets than the LI and LI-BFR for diastolic blood pressure, heart rate and rate-pressure product. The LI-BFR showed higher values than the LI only in the 3rd set for systolic blood pressure, heart rate and rate-pressure product. Blood lactate was higher in the HI (4·2 ± 0·2 mmol) and LI-BFR (4·1 ± 0·3 mmol) than the LI (3·5 ± 0·3 mmol). Rating of perceived exertion was higher in the LI-BFR (7·9 ± 0·3) than the HI (6·4 ± 0·4) and LI (3·2 ± 0·4).

Conclusions: The LI-BFR session exhibited similar blood lactate to the HI, a higher rating of perceived response than the HI and LI, and equal or lower hemodynamic responses than the HI.