High-pressure blood flow restriction with very low load resistance training results in peripheral vascular adaptations similar to heavy resistance training

Abstract

Objective: To investigate vascular adaptations to eight weeks of resistance exercise, with and without different pressures of blood flow restriction (BFR), in the upper and lower body. Approach: Forty individuals (men = 20, women = 20) completed eight weeks of resistance exercise at very low loads (15% of one-repetition maximum (1RM)), with two levels of BFR (40% arterial occlusion pressure (AOP), 80% AOP), without BFR, and 70% of 1RM. Vascular conductance and venous compliance were measured via plethysmography before and following training in the forearms and in the calves. Main results: Values reported as means (95% confidence intervals). Pre to post changes in vascular conductance occurred only in the high-pressure conditions (upper body: +8.29 (3.01–13.57) ml · mmHg−1; lower body: +7.86 (3.37–12.35) ml · mmHg−1) and high-load conditions (upper body: +8.60 (3.45–13.74) ml · mmHg−1); lower body: +7.20 (2.71–11.69) ml · mmHg−1) only. In the upper body, the change was significantly greater in the high-pressure and high-load conditions compared to the change observed in the low-pressure condition (−0.41 (−5.56, 4.73) ml · mmHg−1). These changes were not greater than the change observed in the low-load condition without pressure (+1.81 (−3.47, 7.09) ml · mmHg−1). In the lower body, the change in the high-pressure and high-load conditions were significantly greater than the changes observed with low-load training with (−0.86 (−5.60, 3.87) ml · mmHg−1) and without (−1.22 (−5.71, 3.27) ml · mmHg−1) a low pressure. Venous compliance increased in all groups in the upper body (+0.003 (.000 08, 0.006) ml · 100 ml−1 · mmHg−1) only, with no changes in the lower body. Significance: High-pressure BFR causes adaptations in vascular function following eight weeks of training at mechanical loads not typically associated with such adaptations.