title: Predictors of decreased physical activity level over time among adults: a longitudinal study.
abstract: BACKGROUND
  Leisure-time physical activity (LTPA) plays a key role in chronic disease prevention and health promotion. The impact of life-changing events on LTPA among adults is unknown.
  
  
  OBJECTIVE
  To examine the association between life-changing events and decreased LTPA levels.
  
  
  METHODS
  Eight cycles of Canadian National Population Health Survey data were used for this study. A total of 12,901 respondents aged ≥18 years in 1994-1995 completed biannual follow-ups until 2008-2009. The association between life-changing events and decreased LTPA in any 2-year period was assessed with adjustment of potential confounding factors. Data were analyzed in 2012.
  
  
  RESULTS
  From 1994-1995 to 2008-2009, nine of ten people changed their LTPA levels. Within each 2-year period, individuals were more likely to decrease their LTPA levels if they married within the 2-year period (men); became or remained overweight/obese (women); remained a regular smoker (men); became or remained unhealthy (men and women); developed or continued to have body pain (women); and acquired social support or remained without support (men).
  
  
  CONCLUSIONS
  Most people change their LTPA levels or patterns, which are significantly influenced by life-changing events. An improved understanding of factors that influence LTPA may help better target those at high risk.
authors.affiliation: Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa Canada.
authors.forename: Sulan
authors.initials: S
authors.lastname: Dai
authors.affiliation: Social Determinants and Science Integration Directorate, Public Health Agency of Canada, Ottawa Canada. Electronic address: feng.wang@phac-aspc.gc.ca.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Social Determinants and Science Integration Directorate, Public Health Agency of Canada, Ottawa Canada.
authors.forename: Howard
authors.initials: H
authors.lastname: Morrison
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada; D005260:Female; D005500:Follow-Up Studies; D006293:Health Promotion; D006306:Health Surveys; D006801:Humans; D007899:Leisure Activities; D008016:Life Change Events; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology; D012307:Risk Factors; D012944:Social Support; D013997:Time Factors; D055815:Young Adult