Frequency of Blood-Flow Restriction Resistance Training on Maximal Leg Strength and Arterial Stiffness in Resistance-Trained Young Adults

Introduction: While the benefits of traditional resistance training (TRT) have been demonstrated in past research, the high intensity often used in this type of training has been shown in some studies to acutely increase vasoconstriction and chronically increase arterial stiffness. Blood flow restriction training (BFRT) may mitigate this increase or even decrease arterial stiffness while providing similar training benefits. This study aimed to compare the effects of BFRT once per week (along with another day of TRT; BFRT+TRT) vs. twice per week (BFRT+BFRT) on knee extensor/flexor isokinetic strength and arterial stiffness. Methods: Fifteen participants were randomly assigned to either BFRT+TRT or BFRT+BFRT. Outcome variables included augmentation index normalized to a heart rate of 75 beats per minute (AIx75), pulse-wave velocity (PWV), and isokinetic peak torque of the knee flexors and extensors at both 60 and 180 degrees per second (°/s). The intervention involved leg extension and leg curl exercises at 30% one repetition maximum (1RM) for BFRT and 70% 1RM for TRT, performed two days per week for six weeks with each session separated by at least 48 hours. Results: A two-way repeated measures analysis of variance revealed no significant Group or Time effects on arterial stiffness. There was a significant Time effect, but no Group effect, on all isokinetic strength measures except peak torque extension at 180°/s. Conclusions: The findings of the study suggest that BFRT and TRT have similar effects in increasing peak torque with no adverse effects on arterial stiffness. Two days a week of BFRT can be implemented safely among healthy young adults.