High-pressure blood flow restriction with very low load resistance training results in peripheral vascular...

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.

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.

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.

High-pressure BFR causes adaptations in vascular function following eight weeks of training at mechanical loads not typically associated with such adaptations.