Post-exercise blood flow restriction attenuates hyperemia similarly in males and females.

Abstract

Our laboratory recently demonstrated that post-exercise blood flow restriction attenuated muscle hypertrophy only in females, which we hypothesized may be due to alterations in post-exercise blood flow. The aim of this study is to test our previous hypothesis that sex differences in blood flow would exist when employing the same protocol. Twenty-two untrained individuals (12 females; 10 males) performed two exercise sessions, each involving one set of elbow flexion exercise to volitional failure on the right arm. The experimental condition had blood flow restriction applied for a 3min post-exercise period, whereas the control condition did not. Blood flow was measured using an ultrasound at the brachial artery and was taken 1 and 4min post-exercise. This corresponded to 1min post inflation and 1min post deflation in the experimental condition. There were no differences in the alterations in blood flow between the control and experimental conditions when examined across sex. Increases in blood flow [mean (standard deviation)] were as follows: males 1min [control 764 (577)%; experimental 113 (108)%], males 4min [control 346 (313) %; experimental 449 (371)%], females 1min [control 558 (367)%; experimental 87 (105)%], and females 4min [control 191 (183)%; experimental 328 (223)%]. It does not appear that the sex-specific attenuation of muscle hypertrophy we observed previously can be attributed to different alterations in post-exercise blood flow. Future studies may wish to replicate our previous training study, or examine alternative mechanisms which may be sex specific.