title: Relative validity of 3 accelerometer models for estimating energy expenditure during light activity.
abstract: BACKGROUND
  With physical inactivity inextricably linked to the increasing prevalence of obesity, there is a need for validated methods that measure free-living energy expenditure (EE) within sedentary environments. While accelerometers enable these measurements, few studies have compared device accuracy in such settings. The aim of this study was to investigate the relative validity of the Actigraph, RT3 and SenseWear Armband (SWA).
  
  
  METHODS
  Twenty-three (11 male, 12 female) participants (age: 25.3 ± 6.3 yr; BMI: 22.6 ± 2.7) wore 3 accelerometers at designated sites during a 4-hour stay in the Whole Room Calorimeter (WRC). Participants performed 2 10-minute bouts of light-intensity exercise (stepping and stationary cycling) and engaged in unstructured sedentary activities. EE estimated by accelerometers was compared with WRC EE derived from measurements of gaseous exchange.
  
  
  RESULTS
  The Actigraph and SWA both accurately estimated EE during the stepping exercise. EE estimated by the RT3 during stepping was significantly lower than the WRC value (31.2% ± 15.6%, P < .001). All accelerometers underestimated cycling and unstructured activity EE over the trial period (P < .001).
  
  
  CONCLUSIONS
  The Actigraph and SWA are both valid tools for quantifying EE during light-intensity stepping. These results provide further valuable information on how accelerometer devices may be appropriately used.
authors: School of Health Sciences, Smart Foods Centre, University of Wollongong, Wollongong, NSW, Australia.
authors: Alexander Allan
authors: AA
authors: Wetten
authors: Marijka
authors: M
authors: Batterham
authors: Sze Yen
authors: SY
authors: Tan
authors: Linda
authors: L
authors: Tapsell
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000328:Adult; D015992:Body Mass Index; D002151:Calorimetry; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D057185:Sedentary Behavior; D013997:Time Factors