title: [Study on the validation of the computer science application's activity monitor in assessing the physical activity among adults using doubly labeled water method].
abstract: OBJECTIVE
  Using doubly labeled water method to validate the colmputer science application's activity monitor (CSA) in assessing physical activity of free-living adults in Beijing, in order to develop equations to predict total daily energy expenditure (TEE) and activity related energy expenditure (AEE) from activity counts (AC) and anthropometric variables.
  
  
  METHODS
  A total of 72 healthy adults (33 males and 39 females, mean age 43.6 +/- 4.0 yr) were monitored for 7 consecutive days by CSA. TEE was simultaneously measured using doubly labeled water method. Average AC (counts/min(-1)) was compared with TEE, AEE and physical activity level (PAL).
  
  
  RESULTS
  Physical activity determined by AC was significantly related to data on energy expenditures: TEE (r = 0.31, P < 0.01), AEE (r = 0.30, P < 0.05), and PAL (r = 0.26, P < 0.05). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, fat-free mass (FFM) or BMI and AC (R(2) = 0.52 - 0.70) while AEE was significantly influenced by gender, FFM and AC (R(2) = 0.25 - 0.32).
  
  
  CONCLUSIONS
  AC from CSA activity monitor seemed a useful measure in studying the total amount of physical activity in free-living adults while AC significantly contributed to the explained variation in TEE and AEE.
authors.affiliation: Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Ai-ling
authors.initials: AL
authors.lastname: Liu
authors.forename: Yan-ping
authors.initials: YP
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.forename: Hui
authors.initials: H
authors.lastname: Pan
authors.forename: Xiu-ming
authors.initials: XM
authors.lastname: Han
authors.forename: Guan-sheng
authors.initials: GS
authors.lastname: Ma
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000886:Anthropometry; D001835:Body Weight; D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009043:Motor Activity / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*