Abstract

Methodological problems continue to limit the precision of studies on the aging of cardiorespiratory function, particularly problems of sampling, data standardization, and age-linked changes in physical activity patterns. The useof volunteers biasses both cross-sectional and longitudinal samples, usually towards health conscious, healthy non-smokers of fairly high socio-economic status. Rates of aging are influenced by many chronic conditions prevalent in the elderly; however, if all diseased subjects are excluded from a sample, theresidue is small, and may contain an undue proportion of individuals with goodlongevity. Body mass remains the most popular size reference value, although again its use is complicated by secular and age-related trends of body composition. Changes in physical activity also distort both crosssectional and longitudinal estimates of the age-related deterioration of cardiorespiratory function; neither cross-sectional nor longitudinal data are completely statisfactory, but the former seem to give most realistic values for aging rates. Examples are given of cross-sectional studies carried out on athletes, sedentary subjects and primitive populations. Verf.-Referat (gekuerzt)