Venous hemodynamics during blood flow restriction exercise: Impact of cuff type and arm position.

Purpose: Blood flow restriction (BFR) training is an exercise training modality to accelerate fatigue in exercising limbs by restricting blood flow. Although arterial inflow has been studied, its impact on venous hemodynamics remains unclear. This study examined the effects of cuff type and arm position on venous hemodynamics during BFR exercise.

Methods: Twenty-five young adults completed a randomized, crossover trial performing rhythmic handgrip exercises at 50% of maximum voluntary contraction under three conditions: no cuff (control), narrow semi-elastic (SEP) pneumatic band, and wide-rigid (WR) blood pressure cuff. Different arm positions in relation to the heart were used to account for the effect of gravity and blood pooling on the skeletal muscle pump.

Results: WR produced greater fluid retention vs SEP and No cuff. In No cuff, the increment in forearm volume was greater with the arm placed at and below the heart compared with the arm above the heart (p < 0.05). Such differences were not observed across arm positions with the BFR cuffs. Mean venous blood velocity was greater in No cuff than in SEP and WR (p < 0.001), with no differences between SEP and WR in any arm positions. In No cuff, peak venous blood velocity and venous diameter were greater when the arm was placed below the heart. No such trend was observed with the BFR cuffs. Venous diameter was greater in SEP and WR than in No cuff (p < 0.05).

Conclusion: Although venous hemodynamics are not affected by the types of cuffs, WR cuffs appear to induce greater fluid pooling.