Walking performance and cardiovascular response: associations with age and morbidity--the Health, Aging and Body Composition Study.

<bold>Background: </bold>The long-distance corridor walk is a timed 400-meter walk test used to assess walking endurance in well-functioning men and women aged 70-79 in the Health, Aging and Body Composition Study.<bold>Methods: </bold>We examined walking time along with heart rate and blood pressure response in relationship to prevalent chronic conditions, weight, physical activity, and markers of subclinical disease. Of 3075 participants, 2324 (76%) completed the test with heart rate and blood pressure responses in the range expected for a moderate level of exertion.<bold>Results: </bold>Slower walking time was influenced by both clinical and subclinical disease, and also was strongly related to both low and high body weight and low self-reported physical activity. Heart rate and blood pressure responses were higher with several clinical and subclinical diseases, but heart rate response and recovery were more strongly related to walking time than to disease. Higher body mass index and lower physical activity were associated with greater heart rate response and recovery.<bold>Conclusions: </bold>The independent contribution of both clinical and subclinical disease to walking time supports the use of walking tests as a summary measure of disease in older adults. The independent association of walking time with physical activity suggests that it is sensitive to levels of fitness as well. Together these findings show that walking performance is a valid indicator of physiologic reserve in older adults. [ABSTRACT FROM AUTHOR]