title: Retirement and physical activity: analyses by occupation and wealth.
abstract: BACKGROUND
  Older adults close to retirement age show the lowest level of physical activity. Changes in lifestyle with retirement may alter physical activity levels. This study investigated whether retirement changes physical activity and how the effect differs by occupation type and wealth level.
  
  
  METHODS
  This longitudinal study used the Health and Retirement Study (1996-2002), U.S. population-based data. Analyses were conducted in 2007 and 2008. Physical activity was measured by a composite indicator of participation in either work-related or leisure-time physical activity. Fixed-effects regression models were used to account for confounders and unobserved heterogeneity. The dependent variable was a composite indicator of participation in regular physical activity either at work or during nonworking hours.
  
  
  RESULTS
  Physical activity decreased with retirement from a physically demanding job but increased with retirement from a sedentary job. Occupation type interacted with wealth level, with the negative impact on physical activity of retirement exacerbated by lack of wealth and the positive effect of retirement on physical activity enhanced by wealth.
  
  
  CONCLUSIONS
  Substantial differences in the effect of retirement on physical activity occurred across subgroups. As the number of people approaching retirement age rapidly increases, findings suggest that a growing segment of the nation's population may not sustain an adequate level of physical activity.
authors.affiliation: Palo Alto Medical Foundation Research Institute and Phillip R. Lee Institute for Health Policy Studies, University of California, San Francisco, CA, USA. chungs@pamfri.org
authors.forename: Sukyung
authors.initials: S
authors.lastname: Chung
authors.forename: Marisa E
authors.initials: ME
authors.lastname: Domino
authors.forename: Sally C
authors.initials: SC
authors.lastname: Stearns
authors.forename: Barry M
authors.initials: BM
authors.lastname: Popkin
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D007182:Income; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009790:Occupations; D012179:Retirement; D014481:United States