Walking with leg blood flow restriction : wide-rigid cuffs vs. narrow-elastic bands

Blood flow restriction (BFR) training is becoming a popular form of exercise. The concept is that light-load exercise performed with BFR elicits similar adaptations achieved with traditional heavy-load exercise. Walking exercise in combination with pressurized wide-rigid (WR) cuffs elicits higher cardiac workload and a vascular dysfunction due presumably to reperfusion injury to the endothelium. In contrast, narrow-elastic (NE) BFR bands may elicit different hemodynamic effects, as the limb is able to increase in diameter with increased blood flow accompanying exercise. Purpose: To compare the acute cardiovascular responses to two distinct forms of BFR training during light-intensity exercise. Methods: 15 young healthy participants (M=9, F=6) performed 5 bouts of 2-minute walking intervals at 0.9 m/s with a 1-minute rest and deflation period between bouts with either WR, NE, or no bands placed on both upper thighs. Cuff pressure was inflated to 160 mmHg in WR cuffs and 300 mmHg in NE bands while no cuffs were used for the control. Beat-by-beat blood pressure and heart rate were measured continuously using finger plethysmography. Blood lactate concentration, rating of perceived exertion (RPE), flow-mediated dilation (index of endothelium-dependent vasodilation), and cardio-ankle vascular index (measure of arterial stiffness) were assessed before and after the walking exercise. Results: At baseline, no significant differences existed in any of the variables between the three conditions. Increases in heart rate were greater (p<0.05) in the WR than the NE and control conditions. Increases in systolic and diastolic blood pressure were greater (p<0.05) in the WR than the NE and control conditions, and increases in systolic blood pressure were greater (p<0.05) in the control than the NE condition (150±16 / 85±15 mmHg vs. 127±10 / 66±12 mmHg vs. 130±15 / 66±13 mmHg, respectively). Double product, an index of myocardial oxygen demand, increased to a greater extent in the WR than in the NE and control conditions, and to a greater extent in the control than the NE condition. Increases in perceived exertion and blood lactate concentration were greater (p<0.05) in the WR compared with the NE and control conditions (p<0.05), while no differences were seen between the NE and control conditions. There were no changes (p>0.05) in arterial stiffness or endothelial function in all three trials. Conclusion: Use of wide-rigid BFR cuffs result in a marked increase in blood pressure and myocardial oxygen demand compared with narrow-elastic BFR bands, suggesting that narrow-elastic bands present a safer alternative for at-risk populations to perform BFR exercise.