title: Prolonged sedentary time and physical fitness among Canadian men and women aged 60 to 69.
abstract: BACKGROUND
  Evidence for associations between prolonged sedentary time and breaks in sedentary time and fitness is limited in older adults. This study examines associations between objectively measured and self-reported total sedentary time and breaks in sedentary time with cardiorespiratory and musculoskeletal fitness among Canadian men and women aged 60 to 69.
  
  
  METHODS
  Data from cycles 1 and 2 of the Canadian Health Measures Survey were used for analysis. This is a nationally representative survey with an overall response rate of 53.5%. Men (n = 564) and women (n = 593) aged 60 to 69 were selected for analysis. Sedentary time, breaks in sedentary time, and moderate-to-vigorous physical activity were objectively measured with accelerometers. Leisure sedentary time was self-reported. Cardiorespiratory fitness was assessed with the modified Canadian Aerobic Fitness Test. Musculoskeletal fitness was based on grip strength and flexibility. Linear regression models were adjusted for age, sex, education, body mass index, smoking status and moderate-to-vigorous physical activity.
  
  
  RESULTS
  The number of breaks in measured sedentary time (β:0.47, p = 0.02 ) and the percentage of measured sedentary time spent in bouts lasting at least 20 minutes (β:-0.53, p = 0.01 ) were associated with cardiorespiratory fitness. For men, grip strength was negatively associated with measured total sedentary time (β:-0.03, p = 0.03 ) and sit-and-reach was positively associated with breaks in measured sedentary time (β:0.15, p = 0.02 ). Self-reported sedentary time was not associated with any of the fitness outcomes.
  
  
  CONCLUSIONS
  Among Canadians aged 60 to 69, fitness may be influenced not only by total sedentary time, but also by patterns of sedentary time.
authors.affiliation: Faculty of Health Sciences, Kinesiology, University of Ontario Institute of Technology in Oshawa, Ontario.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Dogra
authors.affiliation: Health Statistics Division, Statistics Canada, Ottawa, Ontario.
authors.forename: Janine M
authors.initials: JM
authors.lastname: Clarke
authors.affiliation: Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, Alberta.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Copeland
mesh_terms: D061725:Accelerometry / Q000295:instrumentation / Q000379:methods; D000368:Aged; D000375:Aging; D000072599:Cardiorespiratory Fitness; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D018737:Hand Strength; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D057185:Sedentary Behavior; D057566:Self Report; D013997:Time Factors
keywords: Aging; exercise; flexibility; functional autonomy; hand strength; physical activity; sitting