Aerobic Exercise for Improving CV Function With Aging
Moderate-intensity continuous aerobic exercise is defined as sustained, rhythmic movements of large muscle groups resulting in increases in heart rate and respiration. Moderate-intensity aerobic exercise can maintain and improve CV health with aging, as well as decrease the risk for CVD across the lifespan (Figure 1). On average, aerobic exercise lowers SBP by 2 to 8 mm Hg, with the largest effect evident in those individuals with the highest initial SBP (i.e., stage II hypertension).[20,21]
Regular aerobic exercise also improves vascular endothelial function in midlife and older men by increasing NO bioavailability, secondary to reductions in superoxide-associated suppression of endothelial function and decreased inflammation.[22–25] However, estrogen-deficient postmenopausal women do not respond as consistently or robustly to aerobic exercise training for improving endothelial function as age-matched men. This likely is due, in part, to the significant reduction in circulating estrogen after the menopausal transition. As such, aerobic exercise trials that have assessed endothelial function via brachial artery flow-mediated dilation (FMDBA) typically demonstrate no benefit of physical activity on endothelial function in estrogen-deficient postmenopausal women, whereas the same exercise stimulus appears to evoke improvements in postmenopausal women with circulating estrogen similar to premenopausal concentrations as a result of sex hormone replacement.[27–29]
Results from cross sectional studies comparing sedentary to endurance-trained middle-aged and older adults suggest that years of vigorous aerobic exercise training mitigates the age-related increase in arterial stiffness.[30–33] However, results from aerobic exercise interventions initiated in midlife are somewhat less clear. Although aerobic exercise interventions in midlife/older men and postmenopausal women have demonstrated improvements in carotid artery compliance,[30,32] improvements in aortic stiffness measured via carotid-femoral pulse wave velocity have been less consistent.[34–36] These inconsistencies may be due to differences in aerobic exercise interventions and study populations, although overall, it appears aerobic exercise is modestly effective at reducing large elastic artery stiffness, especially aortic stiffness, in midlife and older adults.[36,37]
Current physical activity guidelines recommend that older adults participate in at least 150 min of moderate-intensity, or 75 min of vigorous intensity, aerobic exercise per week. Despite the efficacy of aerobic exercise for exerting numerous CV benefits, over 60% of midlife and older adults in the United States do not meet these physical activity guidelines.[16,17] The most cited barrier that prevents midlife/older adults from adhering to physical activity guidelines is lack of time.[39–41] Other common barriers that limit adherence include physical limitations, financial cost, lack of appropriate exercise facilities or equipment, lack of intrinsic motivation, transportation limitations, knowledge gaps on how to implement aerobic exercise, and an overall aversion to aerobic exercise training[40–46] (Figure 1). As such, additional strategies are needed to promote adherence to aerobic exercise guidelines among midlife and older adults.
Exerc Sport Sci Rev. 2022;50(3):107-117. © 2022 American College of Sports Medicine