Vascular health and repair in women across the lifespan: effect of exercise

Introduction: Cardiovascular disease (CVD) is the main global cause of mortality with a death rate higher in females than males. Exercise training has the potential to reduce CVD risk but the optimal exercise type has not been determined. Therefore, the effects of two different types of exercise (interval and continuous) on markers related to CVD risk were assessed in women across the lifespan. Methods: The effect of exercise on vascular health was studied in three different populations of women; young premenopausal, middle-aged overweight/obese, and postmenopausal women. In chapters 4 and 6, 12 healthy and 20 overweight/obese women, respectively, completed either an interval or continuous exercise training programme. In chapter 5, 15 postmenopausal women performed a 30 min moderate-intensity continuous and interval exercise bout, with 9 participants completing a further interval exercise session at a heavy-intensity. Endothelial function, arterial stiffness, circulating angiogenic cell (CAC) number and function, and cardio-respiratory fitness were assessed in these chapters at pre and post-exercise. Results: Arterial stiffness was unaltered following exercise in all chapters. Cardio-respiratory fitness was increased following both interval and continuous exercise training. Brachial artery flow-mediated dilation (FMD) was increased following interval exercise training in young women, unaltered acutely in postmenopausal women, and decreased following interval exercise training in overweight/obese women. CAC number was increased following both types of exercise in young women, but in overweight/obese women, CAC number was only increased after interval exercise training, and was unaltered acutely in postmenopausal women. Markers of CAC function were unaltered following exercise training in healthy young women, but CAC colony-forming units increased acutely following moderate and heavy-intensity interval exercise in postmenopausal women, and CAC adhesion increased following interval exercise training in overweight/obese women. However, continuous exercise (acutely and chronically) did not change endothelial function or CAC function in any study. Discussion: Interval exercise modified more markers of vascular health than continuous exercise. The mechanisms behind this discrepancy might be related to potential differences in the arterial shear stress profiles experienced during the exercise. Future studies are required to explore this theory. Exercise-mediated changes in many variables depended on the baseline health of participants and therefore, highlights that exercise effects are heterogeneous.