Prenatal exercise and cardiovascular health (PEACH) study: the remote effect of aerobic exercise training on conduit artery and resistance vessel function

We assessed the impact of a structured lower-limb aerobic exercise training intervention during pregnancy on brachial artery endothelial function, shear rate and patterns, and forearm blood flow and reactive hyperemia. Twenty-seven pregnant women were recruited and randomized into either a control group (n = 11; 31.0 ± 0.7 years), or an exercise intervention group (n = 16; 32.6 ± 0.9 years). The exercise group completed 40 minutes of aerobic exercise (50-70% heart rate reserve) 3-4 times per week, between the second and third trimester of pregnancy. Endothelial function was assessed using flow-mediated dilation (FMD, normalized for shear stress) at pre- (16-20 weeks) and post-intervention (34-36 weeks). The exercise training group experienced an attenuated increase in mean arterial pressure (MAP) relative to the control group (ΔMAP exercise: +2 ± 2 mm Hg vs. control: +7 ± 3 mm Hg; p = 0.044) from pre- to post-intervention. % FMD change corrected for shear stress was not different between groups (p = 0.460); however, the post-occlusion mean flow rate (exercise: 437 ± 32 mL/min vs. control: 364 ± 35 mL/min; p = 0.001) and post-occlusion anterograde flow rate (exercise: 438 ± 32 mL/min vs. control: 364 ± 46 mL/min; p = 0.001) were larger for the exercise training group compared with controls, post-intervention. Although endothelial function was not different between groups, we observed an increase in microcirculatory dilatory capacity, as suggested by the augmented reactive hyperemia in the exercise training group. Registered at ClinicalTrials.gov: NCT02948439. Novelty: Endothelial function was not altered with exercise training during pregnancy. Exercise training did contribute to improved cardiovascular outcomes, which may have been associated with augmented reactive hyperemia, indicative of increased microcirculatory dilatory capacity.