title: Free-living physical activity and energy expenditure of rural children and adolescents in the Nandi region of Kenya.
abstract: OBJECTIVE
  To examine the relationship between physical activity and energy demands in children and adolescents with highly active lifestyles.
  
  
  METHODS
  Physical activity patterns of 30 rural Kenyan children and adolescents (14 ± 1 years, mean ± SD) with median body mass index (BMI) z-score = -1.06 [-3.29-0.67] median [range] were assessed by accelerometry over 1 week. Daily energy expenditure (DEE), activity-induced energy expenditure (AEE) and physical activity level (PAL) were simultaneously determined using doubly-labelled water (DLW). Active commuting to school was assessed by global positioning system.
  
  
  RESULTS
  Mean DEE, AEE and PAL were 12.2 ± 3.4, 5.7 ± 3.0 MJ/day and 2.3 ± 0.6, respectively. A model combining body mass, average accelerometer counts per minute and time in light activities predicted 45% of the variance in DEE (p < 0.05) with a standard error of DEE estimate of 2.7 MJ/day. Furthermore, AEE accounted for ∼47% of DEE. Distance to school was not related to variation in DEE, AEE or PAL and there was no association between active commuting and adiposity.
  
  
  CONCLUSIONS
  High physical activity levels were associated with much higher levels of energy expenditure than observed in Western societies. These results oppose the concept of physical activity being stable and constrained in humans.
authors.affiliation: College of Medical, Veterinary and Life Sciences, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Ojiambo
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Gibson
authors.forename: Kenn
authors.initials: K
authors.lastname: Konstabel
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Lieberman
authors.forename: John R
authors.initials: JR
authors.lastname: Speakman
authors.forename: John J
authors.initials: JJ
authors.lastname: Reilly
authors.forename: Yannis P
authors.initials: YP
authors.lastname: Pitsiladis
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007630:Kenya; D008297:Male; D009043:Motor Activity; D012424:Rural Population