We examined the contribution of variations in body composition and leisure time physical activity to the age-related decline in peak oxygen consumption (V̇O2) in men and women. Healthy males 17-80 yr old (n = 378) and females 18-81 yr old (n = 224) were characterized for peak V̇O2 from a treadmill test to exhaustion, fat-free mass and fat mass by underwater weighing, and leisure time physical activity. Peak V̇O2 showed a greater absolute decline (P < 0.05) with age in males (r = -0.70, slope = -0.034 l · min-1 · yr- 1; P < 0.01) than in females (r = -0.78, slope = -0.028 l · min-1 · yr- 1; P < 0.01). After statistically controlling for differences in fat-free mass and fat mass, the decline in peak V̇O2 was diminished in both sexes, although a greater rate of decline persisted in males (r = -0.47, slope = - 0.016 l · min-1 · yr-1; P < 0.01) than in females (r = -0.39, slope = - 0.009 l · min-1 · yr-1; P < 0.01). We found that the addition of leisure time physical activity (independent of body composition) to the regression model further attenuated the rate of decline in males (r = -0.40, slope = -0.013 l · min-1 · yr-1; P < 0.01) but did not alter the age- related decline in peak V̇O2 in females (r = -0.39, slope = -0.009 l · min-1 · yr-1; P < 0.01). We conclude that 1) the loss of fat-free mass and the increase in adiposity contribute to the decline in peak V̇O2 with age in men and women and 2) the decline in leisure time physical activity, independent of differences in body composition, is associated with the age- related decline in peak V̇O2 in males but not in females.
All Science Journal Classification (ASJC) codes
- Physiology (medical)