Femoral Blood Flow During Blood Flow Restriction In Males And Females

Abstract

Use of blood flow restriction (BFR) during strength training results in an increase in muscle strength and mass when using light loads (20-30% of 1 RM). Only a few studies have reported actual arterial blood flow characteristics during BFR. In addition, research reporting blood flow characteristics in the dominant and non-dominant limb in both males and females is lacking. PURPOSE: This study compared femoral artery occlusion pressure (AOP) and femoral artery blood flow characteristics at different percentages of AOP between both legs in males and females. METHODS: Participants in this study included 31 physically active and healthy males (n=18) and females (n=13) years of age. Blood flow in the superficial femoral artery (SFA) was measured using Doppler ultrasound and BFR was controlled using a Hokanson E20 Rapid Cuff Inflator with a 10 cm cuff placed on the upper thigh. After measuring the AOP of the SFA, blood flow was measured in a random order at 0%, 20%, 40%, 60%, 80%, and 100% of AOP. This was repeated in the opposite leg. Blood flow was recorded in absolute (mL/min) and relative terms (% unoccluded bloodflow). RESULTS: There was significant difference (p<0.008) in the AOP in the dominant leg (234 vs 188 mmHg) and nondominant leg (206 vs 177 mmHg) between males and females, respectively. After accounting for differences in leg circumference (p<0.001), sex remained a significant (p=0.0001) factor in accounting for differences in AOP. The difference in AOP between the dominant and nondominant leg in males (234 vs 206 mmHg) and females (188 vs 177) were not significant (p=0.123). At each of the occlusion pressures (0%, 20%, 40%, 60%, 80%, 100% of AOP), there were no differences in absolute or relative blood flow between males and females. The relationship between SFA blood flow at occlusion pressures between 0 and 100% of the AOP was curvilinear in both males and females. Blood flow at occlusion pressures between 40% and 80% of AOP was relatively constant. CONCLUSIONS: Significant differences in AOP in males and females can be attributed, in part to differences in leg circumference and sex. The curvilinear relationship between blood flow and occlusion pressure indicates that BFR during exercise can be equally effective a lower pressures (40% AOP) as at higher pressures (80% AOP).