title: Activity Profile and Energy Expenditure Among Active Older Adults, British Columbia, 2011-2012.
abstract: BACKGROUND
  Time spent by young adults in moderate to vigorous activity predicts daily caloric expenditure. In contrast, caloric expenditure among older adults is best predicted by time spent in light activity. We examined highly active older adults to examine the biggest contributors to energy expenditure in this population.
  
  
  METHODS
  Fifty-four community-dwelling men and women aged 65 years or older (mean, 71.4 y) were enrolled in this cross-sectional observational study. All were members of the Whistler Senior Ski Team, and all met current American guidelines for physical activity. Activity levels (sedentary, light, and moderate to vigorous) were recorded by accelerometers worn continuously for 7 days. Caloric expenditure was measured using accelerometry, galvanic skin response, skin temperature, and heat flux. Significant variables were entered into a stepwise multivariate linear model consisting of activity level, age, and sex.
  
  
  RESULTS
  The average (standard deviation [SD]) daily nonlying sedentary time was 564 (92) minutes (9.4 [1.5] h) per day. The main predictors of higher caloric expenditure were time spent in moderate to vigorous activity (standardized β = 0.42 [SE, 0.08]; P < .001) and male sex (standardized β = 1.34 [SE, 0.16]; P < .001). A model consisting of only moderate to vigorous physical activity and sex explained 68% of the variation in caloric expenditure. An increase in moderate to vigorous physical activity by 1 minute per day was associated with an additional 16 kcal expended in physical activity.
  
  
  CONCLUSIONS
  The relationship between activity intensity and caloric expenditure in athletic seniors is similar to that observed in young adults. Active older adults still spend a substantial proportion of the day engaged in sedentary behaviors.
authors.affiliation: University of British Columbia, Gordon and Leslie Diamond Health Care Centre, Room 7185, 2775 Laurel St, Vancouver, BC, Canada, V5Z 1M9. Email: Kenneth.Madden@ubc.ca.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Madden
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Maureen C
authors.initials: MC
authors.lastname: Ashe
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jocelyn M
authors.initials: JM
authors.lastname: Chase
mesh_terms: D061725:Accelerometry; D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001955:British Columbia; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006293:Health Promotion / Q000379:methods; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods; D015999:Multivariate Analysis; D057185:Sedentary Behavior; D013997:Time Factors; D016138:Walking / Q000502:physiology*