Blood flow responses to different set pressures using elastic "multichambered" blood flow restriction bands

The blood flow responses to blood flow restriction (BFR) with "multi-chambered" BFR bands are not well understood. This study investigated the blood flow responses to four set pressures in the arm and leg using B-Strong BFR bands.

Ultrasound was used to measure unoccluded blood flow prior to measuring blood flow at each of four set pressures (200, 300, 400, 500 mmHg) in the arm and the leg in 60 participants (30 males; 30 females).

A set pressure of 500 mmHg was unable to occlude blood flow in both limbs in all participants. Blood flow at each set pressure was expressed relative to the paired measure of unoccluded blood flow. There were no significant sex differences in relative blood flow at each set pressure in either the arm (p = 0.7088) or the leg (p = 0.9920). There was a main effect for the blood flow responses between set pressures in the arm (p < 0.0001) and the leg (p < 0.0001). In both males and females, paired comparisons indicated that blood flow was significantly different between all set pressures (p < 0.05), except between 300 and 400 mmHg (p = 0.0752) in the arm and between set pressures of 200 and 300 mmHg in the leg (p = 0.2518).

The wide range of blood flow responses to each set pressure in both limbs presents challenges to determining an effective set pressure to use during BFR training and suggests the possibility of diverse outcomes with BFR training with B-Strong bands. Nevertheless, the wide range of blood flow responses does not preclude muscle adaptations as they are the result of multiple factors. The practical use of using elastic "multi-chambered" BFR bands requires further investigation to guide the determination of effective set pressures during exercise.