Blood pressure response to dynamic resistance exercise with different times under blood flow restriction on normotensive subjects: a randomized crossover trial

Introduction: Recommendations for time under blood flow restriction (BFR) during resistance training (RT) vary between 5 to 10 minutes, and beneficial effects on muscle mass and strength have already been reported. However, there exists the potential for longer times under restriction to produce greater acute activation of the exercise pressor reflex and subsequent sympathetic pathways leading to a greater hemodynamic response. Objective: To verify blood pressure responses to dynamic resistance exercise with different times (5 vs. 10 minutes) under blood flow restriction in normotensive subjects. Methods: In a randomized crossover trial design, twelve healthy and physically active male participants completed a training with BFR under the following protocols: control, BFR-5 minutes, BFR-10 minutes. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements were taken by an experienced researcher immediately after each exercise set. Results: Both BFR-5 minutes and BFR-10 minutes induced acute elevations in SBP, DBP and heart rate (HR) as the sets progressed, without statistical differences between them. However, BFR-10 displayed a superior effect size for SBP and DBP compared to BFR-5 minutes. Conclusion: Based on the present study results, the time under BFR during resistance exercise does not affect blood pressure response in normotensive subjects.