Gender differences in the decline in aerobic capacity and its physiological determinants during the later decades of life

We investigated the hemodynamic determinants of the age-associated decline in maximal oxygen uptake (V̇o2 max) and the influence of gender on the decline in V̇o2 max and its determinants in old and very old men and women. Sedentary, 60- to 92-yr-old women ( n = 71) and men ( n = 29), with no evidence of cardiovascular disease, underwent maximal treadmill exercise tests during which V̇o2 max and maximal cardiac output (Q̇max) were determined. V̇o2 max and age were inversely related in both women (−23 ± 2 ml·min−1·yr−1; P < 0.0001) and men (−57 ± 5 ml·min−1·yr−1; P < 0.0001). The absolute slope of the V̇o2 max vs. age relationship was twofold steeper in men than in women ( P < 0.0001). Q̇max was also inversely related to age in a gender-specific manner (women = −87 ± 25 ml·min−1·yr−1, P = 0.0009; men = −215 ± 50 ml·min−1·yr−1, P = 0.0002; P = 0.01 women vs. men). Age-related changes in maximal exercise arteriovenous oxygen content difference (a-vDo2) were marginally different ( P = 0.08) between women (−0.12 ± 0.03 ml·dl−1·yr−1, P = 0.0003) and men (−0.22 ± 0.04 ml·dl−1·yr−1, P < 0.0001). Age-associated decreases in Q̇max and a-vDo2 contributed equally to the declines in V̇o2 max in both men and women. In the later stages of life, V̇o2 max, Q̇max, and a-vDo2 decrease with age more rapidly in older men than they do in older women. As a result, the gender differences dissipate in the later decades of life. Declines in Q̇max and a-vDo2 contribute equally to the age-related decrease in V̇o2 max in men and women.