Aerobic fitness in a population of independently living men and women aged 55-86 years

Purpose: The purpose was to examine, for a subset of a large random survey of men and women, the age-related changes in the parameters of aerobic function, maximal oxygen consumption ((V)over dotO(2max)), and ventilatory threshold ((T)over dot(VE)). Methods: A "ramp-like" treadmill protocol was designed to measure (V)over dotO(2max) and (T)over dot(VE) on a total of 298 subjects (152 men and 146 women), aged 55-86 yr. Results: Data for VO2max (and HRmax) and (T)over dot(VE), by 5-yr age groups provide "normative" results. Age-related declines in (V)over dotO(2max) and (T)over dot(VE) were fit by a linear model; however, age explained at most 37% of the variance across ages 55-86 yr. In this restricted age range, the rate of decline in (V)over dotO(2max) in both men (-0.034 L.min(-1).yr(-1)) and women (-0.019 L.min(-1).yr(-1)), was similar to that of previous reports for linear regression with age. Men, but not women, showed a decrease in body mass across age. Thus, the decline in (V)over dotO(2max) expressed relative to body mass was similar in men (0.31 mL.kg(-1).min(-1).yr(-1)) and women (0.25); however, across this older age the decline is slower than noted for younger groups. The minimum level of aerobic power compatible with an independent life at age 85 yr was approximately 18 mL.kg(-1).min(-1) in men and 15 mL.kg(-1).min(-1) in women. Regression analysis showed HRmax across this age span is not well predicted by age. (T)over dot(VE) across age declined at about one-half the rate of the (V)over dotO(2max), and in older age was approximately 85% of the (V)over dot not equivalent to O-2max. Conclusion: The study provides "normative" cardiorespiratory function data of a random sample of independently living men and women aged 55-86 yr.