title: Validation of a 7-day physical activity diary against doubly-labelled water.
abstract: BACKGROUND
  The assessment of physical activity intensity and duration is essential for understanding group activity patterns.
  
  
  METHODS
  The present study evaluated the validity of measurement of total energy expenditure (TEE) and physical activity level (PAL) using a categorized physical activity diary. In 29 young healthy men, aged 18-27 years, with body mass index range 21-43 kg m(-2), TEE using doubly-labelled water (DLW), resting metabolic rate (RMR) by indirect calorimetry, physical activity level (PAL defined as TEE/RMR) and activity pattern, timing and level from 7-day physical activity diaries were determined.
  
  
  RESULTS
  TEE by DLW and estimated by activity diary were correlated (r = 0.61, p = 0.005). The mean underestimation of TEE by the activity diary compared with the DLW method was 2.50 +/- 0.72 MJ day(-1). Sedentary (lying, sitting and standing) time averaged 18 h day(-1) and was negatively correlated with PAL (r = -0.44, p = 0.018) whilst time spent in light intensity activity (5 h day(-1)) was positively correlated (r = 0.51, p = 0.005).
  
  
  CONCLUSIONS
  It is concluded that the categorized physical activity diary measured TEE with limited accuracy but presents an inexpensive, convenient method of discriminating individual and group physical activity patterns.
authors.affiliation: Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand. elaine.rush@aut.ac.nz
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Rush
authors.forename: Mauro E
authors.initials: ME
authors.lastname: Valencia
authors.forename: Lindsay D
authors.initials: LD
authors.lastname: Plank
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D017666:Deuterium Oxide; D004734:Energy Metabolism; D015444:Exercise; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D008297:Male; D009043:Motor Activity; D011996:Records / Q000592:standards*; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D017666:Deuterium Oxide