Resistance Exercise Training Status Augments Microvascular Responses to Acute Resistance Exercise in Middle-Aged Women

INTRODUCTION/PURPOSE: Women experience increased hypertension risk in midlife, which may impact cerebrovascular hemodynamics. Resistance exercise training has emerged as a key means to target hypertension risk. Older women experience beneficial vascular effects of resistance exercise training from repeated exposures to acute resistance exercise (RE). To investigate acute RE and vascular health in women, we evaluated the impact of acute RE on macrovascular, microvascular, and cerebrovascular function in untrained and resistance-trained middle-aged women.

METHODS: The following measurements were performed before and after acute RE in 23 untrained (51±6yr) and 19 resistance-trained (48±6yr; 10.6±11.1yr resistance training experience) middle-aged women: macrovascular function (brachial artery flow-mediated dilation [FMD]), microvascular function [reactive hyperemic area under the curve (RHAUC) during FMD], and middle cerebral artery blood velocity (MCAv) and cerebrovascular reactivity (CVR). Acute RE included 3 sets of 8-12 repetitions at 60-80% of 1 repetition maximum (1RM) for 8 resistance exercises.

RESULTS: While there was no effect of acute RE or training status on FMD, both groups exhibited decreased normalized FMD, MCAv, and MCA conductance after acute RE (RE effect: p=0.003, p=0.01, p=0.002). Resistance-trained middle-aged women exhibited exaggerated RHAUC increases after acute RE as compared to untrained middle-aged women (interaction: p=0.005). Further, there may be a differential CVR response (interaction: p=0.046) between untrained and resistance-trained middle-aged women that warrants further investigation.

CONCLUSION: The findings suggest acute RE reduces macrovascular function and MCAv while increasing microvascular function in middle-aged women, indicating differential effects of acute RE along the vascular tree. Further, resistance exercise training status appears to augment microvascular responses to acute RE in middle-aged women compared to untrained counterparts.