We investigated the hemodynamic determinants of the age-associated decline in maximal oxygen uptake (VO₂max) and the influence of gender on the decline in VO₂max and its determinants in old and very old men and women. Sedentary, 60- to 92-year-old women (n=71) and men (n=29), with no evidence of cardiovascular disease, underwent maximal treadmill exercise tests during which VO₂max and maximal cardiac output (Qmax) were determined. VO₂max and age were inversely related in both women (-23±2 mL^.min^-1 per year; p<0.0001) and men (-57±5 mL[[rad]]min^-1 per year; p<0.0001). The absolute slope of the VO₂max versus age relationship was 2-fold steeper in men than in women (p<0.0001). Qmax was also inversely related to age in a gender-specific manner (women=-87±25 mL^.min^-1 per year, p=0.0009; men=-215±50 mL^.min^-1 per year, p=0.0002; p=0.01 women vs. men). Age-related changes in maximal exercise arteriovenous oxygen content difference (AVO₂diff) were marginally different (p=0.08) between women (-0.12 ± 0.03 mL/dL per year, p<0.0001) and men (-0.22±0.04 mL/dL per year, p<0.0001). Age-associated decreases in Qmax and AVO₂diff contributed equally to the declines in VO₂max in both men and women. In the later stages of life, VO₂max, Qmax, and AVO₂diff 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 Qmax and AVO₂diff contribute equally to the age-related decrease in VO₂max in men and women.