title: Prospective study of physical activity and physical function in early old age.
abstract: BACKGROUND
  In the elderly, higher levels of physical function have consistently been associated with higher levels of physical activity. In this study, we test the hypothesis that physical activity earlier in the life course preserves high physical function over an extended period of time, before the onset of major age-related declines in physical function.
  
  
  METHODS
  A cohort study with an average of 8.8 years of follow-up (1991-1993 to 2001). Logistic regression analyses were conducted adjusting for long-standing illness, baseline physical function, smoking, body mass index, and employment grade. Participants were 6398 London-based civil servants aged 39 to 63 years at baseline, 90% of whom were working. The main outcome measure was physical function measured by the Short Form (SF-36) General Health Survey.
  
  
  RESULTS
  Relatively fit and healthy, mainly working, middle-aged men and women who were physically active at recommended levels, were more likely to report high physical function at follow-up, compared to their sedentary counterparts (odds ratio 1.63, 95% confidence interval 1.32-2.00). The association between initial level of physical activity and high physical function at follow-up remained after adjustment for baseline level of physical function and the presence of long-standing illness.
  
  
  CONCLUSIONS
  Participation in a physically active lifestyle during mid-life appears to be critical to the maintenance of high physical function in those who are fit and well enough to work and do or do not report any long-standing illness.
authors.affiliation: International Centre for Health and Society, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, England. m.hillsdon@ucl.ac.uk
authors.forename: Melvyn M
authors.initials: MM
authors.lastname: Hillsdon
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Brunner
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Michael G
authors.initials: MG
authors.lastname: Marmot
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D015992:Body Mass Index; D004651:Employment; D015444:Exercise; D005260:Female; D006304:Health Status; D006801:Humans; D016015:Logistic Models; D008131:London; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012907:Smoking