title: Inverse effects of midlife occupational and leisure time physical activity on mobility limitation in old age--a 28-year prospective follow-up study.
abstract: OBJECTIVE
  To evaluate in a sample of initially middle-aged municipal employees whether leisure time (LPA) or occupational physical activity (OPA) was associated with mobility limitation (ML) in old age.
  
  
  METHODS
  Prospective population-based follow-up.
  
  
  METHODS
  Municipalities in Finland.
  
  
  METHODS
  Public sector employees from the Finnish Longitudinal Study on Municipal Employees (FLAME) initially aged 44 to 58 (N = 5,200).
  
  
  METHODS
  Baseline data were collected in 1981, including LPA (average exercise within previous year: inactive (no exercise), moderate (some form of exercise ≤ 1 time per week), vigorous (brisk exercise ≥ 1 time per week)) and OPA (usual activities at work within previous year: light (light work sitting, standing, or moving around), moderate (moderate work moving around), vigorous (heavy physical work)). Number of MLs was assessed using a questionnaire (8 items) in 1985, 1992, 1997, and 2009; the latest mobility score available for each subject was used for analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for LPA and OPA predicting ML were estimated in a joint Poisson regression model adjusted for survival data; the other type of PA; and sociodemographic, socioeconomic, and health-related factors.
  
  
  RESULTS
  Mean age at baseline was 50.3 ± 3.6; 56.9% of participants were female. Participants with vigorous OPA in midlife had greater risk of a unit increase in ML in old age than those with light OPA (fully adjusted IRR = 1.09, 95% CI = 1.03-1.16). Participants with vigorous LPA had lower risk of ML than inactive participants (fully adjusted IRR = 0.81, 95% CI = 0.76-0.86).
  
  
  CONCLUSIONS
  Findings suggest that LPA and OPA in midlife have independent, inverse effects on mobility in old age in terms of a harmful effect of vigorous OPA and a protective effect of vigorous LPA.
authors.affiliation: Swiss Paraplegic Research, Nottwil, Switzerland; Department of Sports Medicine and Sports Nutrition, University of Bochum, Bochum, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Hinrichs
authors.forename: Mikaela B
authors.initials: MB
authors.lastname: von Bonsdorff
authors.forename: Timo
authors.initials: T
authors.lastname: Törmäkangas
authors.forename: Monika E
authors.initials: ME
authors.lastname: von Bonsdorff
authors.forename: Jenni
authors.initials: J
authors.lastname: Kulmala
authors.forename: Jorma
authors.initials: J
authors.lastname: Seitsamo
authors.forename: Clas-Håkan
authors.initials: CH
authors.lastname: Nygård
authors.forename: Juhani
authors.initials: J
authors.lastname: Ilmarinen
authors.forename: Taina
authors.initials: T
authors.lastname: Rantanen
mesh_terms: D000328:Adult; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D005544:Forecasting; D015438:Health Behavior; D006801:Humans; D007899:Leisure Activities / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009043:Motor Activity / Q000502:physiology*; D016272:Occupational Health; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: aging; longitudinal studies; mobility limitation; occupational class; physical activity