Article

Recommendations on minimum exercise levels for the elderly have to date been based largely on extrapolation of epidemiological findings in middle-aged adults. Questionnaire assessments of physical activity in the latter age group have been correlated with health outcomes observed over 10 or more years. The reliability and construct validity of questionnaires have sometimes been reasonably high, but information on the volume of physical activity has been exaggerated as much as three- to five-fold, with corresponding uncertainties in health inferences.
Objectives: To assess the contribution of inexpensive pedometer/accelerometers to objective determinations of physical activity needs in the elderly.
Major findings: Pedometer/accelerometers work well in the elderly, whose main deliberate activity is walking. The steps taken on a treadmill or a walking course can be determined with considerable accuracy, but more tests are needed under free-living conditions. In elderly people, the relationship between step counts and health outcomes is progressive; even a small increase in daily activity yields some health benefit. For many outcomes, advantage is seen with a nominal count of 8000 steps/day, probably reflecting 4000 paces of deliberate walking, and the spending of at least 20 minutes per day at an exercise intensity >3 METs. This corresponds to a weekly energy expenditure of 1-2 MJ, substantially less than inferred from some questionnaire analyses.
Conclusions: Cross-sectional analyses show that healthier old people reach a nominal count of 8000 steps/day, exercising >20 minutes per day at an intensity >3 METs. Longitudinal studies are needed to test the causality of these relationships.

Langue : ANGLAIS