Effects of leisure and non-leisure physical activity on mortality in U.S. adults over two decades

To estimate the effects of the components of total physical activity, leisure-time and non-leisure activity, on all-cause mortality over two decades in a large, nationally representative sample of U.S. adults.

We used the first National Health and Nutrition Examination Survey (NHANES I, 1971-1975) and its Epidemiologic Followup Study (NHEFS), which tracked deaths of NHANES I participants through 1992. Using multivariable Cox regression, and multiple imputation for missing values of control variables, we related baseline leisure-time and non-leisure physical activity to all-cause mortality during follow-up, controlling for other risk factors. Adults 35 through 59 years of age (N = 5884) and 60 through 74 years of age (N = 4590) were analyzed separately.

For persons aged 35-59, moderate non-leisure activity at baseline significantly reduced mortality risk over the next two decades by about 26%, high non-leisure activity by about 37%, compared with low non-leisure activity. For persons 60-74, risk reductions were 34% and 38%, respectively. Leisure-time activity was associated with lower mortality, but was not consistently significant when both types of activity were entered in the regressions.

Over two decades, non-leisure physical activity was associated with a substantial reduction in all-cause mortality. These results contribute to a growing number of studies that support the importance of measuring all physical activity.