Physical Activity at Midlife in Relation to Successful Survival in Women at Age 70 Years or Older

A large number of studies have shown that physical activity improves overall health, reduces the risks of many chronic diseases, and may prevent premature death. It is unclear whether the benefits of physical activity found at midlife also occur in physically active individuals 65 and older. This study used data from the Nurses' Health Study to examine the relation between midlife physical activity, including walking and successful aging defined as a full spectrum of health outcomes. The study population was comprised of 13,535 women enrolled in the Nurses' Health Study, who were free of major chronic diseases at baseline in 1986 and had survived to age 70 years or older as of 1995 to 2001. The concept of successful aging accounts for both comorbidities and disabilities, and was used to evaluate the overall health status of the study participants. Successful aging was defined as no history of 10 major chronic diseases and coronary artery bypass graft surgery, no physical disabilities, and no impairment in cognitive function or mental health limitations. A successful survivor was any participant who met these criteria and survived to at least age 70 years. Metabolic-equivalent tasks (METs) measured in hours per week were used to calculate energy expenditure. The study participants were grouped into quintiles of total METs. Adjustment for covariables was performed with multivariate logistic regression models. A total of 1456 (10.8%) of the 13,535 participants were successful survivors. The adjusted odds ratios (aORs) of successful survival associated with each quintile were estimated, with the lowest quintile defined as the reference. Multivariate analysis showed that higher physical activity levels at midlife, as measured by METs, were significantly associated with greater likelihood of successful survival. Significant increases in the odds of successful survival were found; the aORs across quintiles (with 95% confidence intervals) were 1 (reference), 0.98 (0.80–1.20), 1.37 (1.13–1.65), 1.34 (1.11–1.61), and 1.99 (1.66–2.38); P < 0.001 for trend. A significant elevation in the odds of successful survival was also associated with increasing energy expenditure from walking; the aORs (95% confidence intervals) across quintiles of walking were 1 (reference), 0.99 (0.80–1.21), 1.19 (0.97–1.45), 1.50 (1.24–1.82), and 1.47 (1.22–1.79); P < 0.001 for trend. These findings present evidence that midlife physical activity is associated with increased odds of exceptional health status among women who are initially healthy at midlife and survive to older ages. The data suggest that physical activity can promote successful survival beyond just extending the lifespan.