title: Does strenuous leisure time physical activity prevent severe back disorders leading to hospitalization?
abstract: METHODS
  Prospective cohort study.
  
  
  OBJECTIVE
  To study the associations between strenuous leisure time physical activity (LTPA) and subsequent hospitalization due to back disorders. Socioeconomic and lifestyle factors are associated with back-related hospitalization, but the significance of strenuous LTPA in the working population is unclear.
  
  
  METHODS
  The cohort (n = 902) was drawn from among employees in the metal industry (n = 2,653). Data were collected by a questionnaire and a structured interview on LTPA. Activity regarding strenuous (>500 kcal/h) LTPA was categorized as none, some, and high. Information from national registers on hospitalizations and deaths during 28 years of follow-up was linked to the data. Cox proportional hazards regression was used.
  
  
  RESULTS
  Subjects with a high level of strenuous LTPA had a decreased risk of hospitalization due to back disorders (hazard ratio 0.40; 95% CI 0.21-0.79) compared with persons with no strenuous activity, after adjustment for age and gender. The association persisted (0.48; 0.24-0.96) when further adjusted for occupational class, self-reported back diseases, smoking, and body mass index at baseline.
  
  
  CONCLUSIONS
  Strenuous LTPA decreased the risk of inpatient hospital care for back disorders among industrial employees.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland, sanna.kaaria@multicom.fi.
authors.forename: Sanna
authors.initials: S
authors.lastname: Kääriä
authors.forename: Juhani
authors.initials: J
authors.lastname: Kirjonen
authors.forename: Risto
authors.initials: R
authors.lastname: Telama
authors.forename: Leena
authors.initials: L
authors.lastname: Kaila-Kangas
authors.forename: Päivi
authors.initials: P
authors.lastname: Leino-Arjas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007899:Leisure Activities; D008019:Life Style; D017116:Low Back Pain / Q000517:prevention & control*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D057566:Self Report; D011795:Surveys and Questionnaires