Physical activity at age of 20-64 years and mobility and muscle strength in old age: a community-based study.

BACKGROUND Physical activity in midlife has been related to lower mortality and better health in old age. The present study evaluated whether physical activity at age of 20-64 years was associated with mobility and muscle strength in old age. METHODS A random sample of 1,000 persons was extracted from all the ≥75-year-old people living in Kuopio, Finland, and 679 community-dwelling participants were included in the present analyses. Data on health status, ability to walk outside or 400 m, and physical activity level were obtained through structured interviews. Participants' walking speed, grip strength, and knee extension strength were measured by physiotherapists. Relationship between physical activity at age of 20-64 years and old-age mobility and strength was assessed using logistic regression and covariance analyses. RESULTS Of the 679 participants (mean age 80.8 years), 58.8% had been physically active at age of 20-64 years. Physical activity at that age was positively associated with ability to walk 400 m independently in old age (adjusted odds ratio 2.17, 95% confidence intervals: 1.25-3.77). Men who had been physically active at age of 20-64 years had greater walking speed (adjusted p = .01) and grip strength (adjusted p = .02) compared with physically inactive men. In women, the results did not differ statistically significantly. CONCLUSIONS Physical activity at age of 20-64 years was associated with better mobility in old age. It was also linked to better grip strength and walking speed in older men but not in women.