title: What factors are associated with physical activity in older people, assessed objectively by accelerometry?
abstract: OBJECTIVE
  To assess physical activity (PA) levels measured objectively using accelerometers in community-dwelling older people and to examine the associations with health, disability, anthropometric measures and psychosocial factors.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  Single general practice (primary care centre), United Kingdom.
  
  
  METHODS
  Random selection of 560 community-dwelling older people at least 65 years old, registered with the practice. 43% (238/560) participated.
  
  
  METHODS
  Participants completed a questionnaire assessing health, disability, psychosocial factors and PA levels; underwent anthropometric assessment; and wore an accelerometer (Actigraph) for 7 days.
  
  
  METHODS
  Average daily accelerometer step-counts and time spent in different PA levels. Associations between step-counts and other factors were examined using linear regression.
  
  
  RESULTS
  Average daily step-count was 6443 (95% CI 6032 to 6853). Men achieved 754 (84 to 1424) more steps daily than women. Step-count declined steadily with age. Independent predictors of average daily step-count were: age; general health; disability; diabetes; body mass index; exercise self-efficacy; and perceived exercise control. Activities associated independently with higher step-counts included number of long walks and dog-walking. Only 2.5% (6/238) of participants achieved the recommended 150 minutes weekly of at least moderate-intensity activity in > or = 10 minute bouts; 62% (147/238) achieved none.
  
  
  CONCLUSIONS
  This is the first population-based sample of older people with objective PA and anthropometric measures. PA levels in older people are well below recommended levels, emphasising the need to increase PA in this age group, particularly in those who are overweight/obese or have diabetes. The independent effects of exercise self-efficacy and exercise control on PA levels highlight their role as potential mediators for intervention studies.
authors.affiliation: Division of Community Health Sciences, St George's, University of London, Cranmer Terrace, Tooting, London, SW17 ORE, UK. tharris@sgul.ac.uk
authors.forename: T J
authors.initials: TJ
authors.lastname: Harris
authors.forename: C G
authors.initials: CG
authors.lastname: Owen
authors.forename: C R
authors.initials: CR
authors.lastname: Victor
authors.forename: R
authors.initials: R
authors.lastname: Adams
authors.forename: D G
authors.initials: DG
authors.lastname: Cook
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000886:Anthropometry; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods; D010809:Physical Fitness / Q000502:physiology*; D012737:Sex Factors; D012959:Socioeconomic Factors; D006113:United Kingdom; D016138:Walking