Section: Original Research
Authors: Alexander Allan Wetten, Marijka Batterham, Sze Yen Tan, and Linda Tapsell
Affiliations: Wetten, Tan and Tapsell are with School of Health Sciences, Smart Foods Centre, University of Wollongong, Wollongong, NSW, Australia. Batterham is with Statistical Consulting Service, University of Wollongong, Wollongong, NSW, Australia.
Acceptance Date: September 25, 2012
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. Our aim 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 three accelerometers at designated sites during a four-hour stay in the Whole Room Calorimeter (WRC). Participants performed two 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 < 0.001). All accelerometers underestimated cycling and unstructured activity EE over the trial period (P < 0.001).
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.
Key Words: accelerometry, whole room calorimeter, sedentary, accuracy.