TREADMILL EXERCISE TESTING IN AN EPIDEMIOLOGIC-STUDY OF ELDERLY SUBJECTS

We sought to characterize the physical performance of older subjects i n a community-based study of aging and fitness and to establish norms of oxygen consumption during exercise in this group. A community-based census identified 3057 age-eligible individuals of whom 2092 individu als (68.4%) agreed to participate in the overall study. Of these, 1101 subjects between 55 and 94 years of age who were free of known heart disease and able to perform treadmill exercise were tested using the C ornell protocol. Of these 1101 subjects, 73.8% of women and 89.5% of m en (p < .001) exceeded what was considered a minimal threshold workloa d [i.e., greater than or equal to 2 min of exercise and a respiratory exchange ratio (RER) greater than or equal to 1.00] Moreover, 32.9% of women and 52. 7% of men achieved a RER greater than or equal to 1.10 and were considered to have achieved maximal exercise. For all subject s who exceeded the minimal exercise workload, the mean exercise durati on was 10.0 +/- 4.0 min for women and 13.2 +/- 4.6 min for men. Peak ( V) over dot O-2/kg.min(-1) decreased linearly with age for both women (y = 38.33 - 0.27.age + 1.12H) and men (y = 41.78 - 0.26.age + 12.65H - 0.15H.age), (p <.001 for sex difference), where H is defined as pres ence (=1) or absence (=0) of a disease rendition. However, this sex-re lated difference disappeared when (V) over dot O-2/kg.min(-1) was adju sted for lean body mass. Thus, from a community-based sample of older persons, we have provided data (by 5-year age groups) for rates of par ticipation irt treadmill exercise testing and the success rate for ach ieving maximal Exercise. Oxygen consumption and other exercise data ar e presented for older, healthy subjects as well as for those,vith vari ous chronic diseases associated with aging (excluding those with cardi ac or cerebrovascular disease). Exercise duration, peak (V) over dot O -2/kg.min(-1) (normalized for total and lean body mass), and peak exer cise heart rate declined,vith age. Most of the sex difference in peak (V) over dot O-2/kg.min(-1) could be explained by the greater percent of body fat in women.