title: Effects of leisure and non-leisure physical activity on mortality in U.S. adults over two decades.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Indiana University School of Public and Environmental Affairs, Indianapolis, IN, USA.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Arrieta
authors.forename: Louise B
authors.initials: LB
authors.lastname: Russell
mesh_terms: D000328:Adult; D000368:Aged; D016021:Epidemiologic Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D007899:Leisure Activities; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009043:Motor Activity; D015999:Multivariate Analysis; D012044:Regression Analysis; D014481:United States / Q000453:epidemiology