Sex differences in ventricular-vascular coupling following endurance training

Ventricular and vascular coupling is defined as the ratio of arterial elastance (Ea) to ventricular elastance (Elv) and describes the interaction between the heart and arterial system. There are sex differences in both arterial and ventricular function in response to both acute exercise and aerobic exercise training. To examine the effects of aerobic exercise training on elastances and the coupling ratio in young adult men and women. We hypothesized a reduction in the coupling ratio in both sexes due to a decrease in Ea that would be more pronounced in men and an increase in Elv that would be larger in women. Fifty-three healthy, young adults completed the study. Central pulse wave velocity and heart volumes were measured before and after an 8-week aerobic training intervention. Elastances were calculated as Ea = end-systolic pressure/stroke volume and Elv = end-systolic pressure/end-systolic volume and indexed to body surface area. After the intervention, women augmented indexed and un-indexed Elv from 2.09 +/- A 0.61 to 2.52 +/- A 0.80 mmHg/ml, p < 0.05, and reduced the coupling ratio from 0.72 +/- A 18 to 0.62 +/- A 15, p < 0.05, while men maintained their pre-training ratio (from 0.66 +/- A 0.20 to 0.74 +/- A 0.21, p > 0.05). Women also reduced end-systolic pressure (from 91 +/- A 10 to 87 +/- A 10 mmHg), and both groups reduced central pulse wave velocity (from 6.0 +/- A 1.0 to 5.6 +/- A 0.6 m/s, p < 0.05). We conclude that after 8 weeks of aerobic training, only women reduced their coupling ratio due to an increase in Elv. This suggests that aerobic exercise training elicits sex-dependent changes in the coupling ratio in young, healthy individuals.