Have we oversold the benefit of late-life exercise?

BACKGROUND: Increasing exercise among older adults to improve function and prevent or decrease disability is widely promoted in developed countries. This review seeks to critically evaluate the degree to which existing scientific evidence supports these claims.
METHODS: A literature review was performed in Medline and Best Evidence databases for the years 1985 to 2000. Experimental and quasi-experimental aerobic and resistance exercise interventions were reviewed for impairment, function, and disability outcomes. The impact of exercise on specific impairments, functions, and disabilities was examined by summarizing the findings reported across all studies.
RESULTS: Thirty-one studies were identified. Impairment and functional outcomes were reported in 97% and 81% of the studies, respectively; half of the studies examined disability outcomes. The most consistent positive effects of late-life exercise were observed in strength, aerobic capacity, flexibility, walking, and standing balance, with over half of the studies that examined these outcomes finding positive effects. Of the studies that examined physical, social, emotional, or overall disability outcomes, most found no improvements. In the five studies that reported reduced physical disability, the effect sizes ranged from .23 to .88.
CONCLUSIONS: Late-life exercise clearly improves strength, aerobic capacity, flexibility, and physical function. Existing scientific evidence, however, does not support a strong argument for late-life exercise as an effective means of reducing disability. This may be due, in part, to methodological limitations in studies that have examined disability outcomes. On the other hand, the theoretical basis of interventions aimed at reducing disability may need to extend beyond exercise and address behavioral and social factors.