title: Self-report vs. objectively assessed physical activity: which is right for public health?
abstract: BACKGROUND
  To examine the agreement between self-reported and objectively assessed physical activity (PA) according to current public health recommendations.
  
  
  METHODS
  One-hundred and fourteen British University students wore a combined accelerometer and heart rate monitor (Actiheart; AHR) to estimate 24-hour energy expenditure over 7 consecutive days. Data were extracted based on population-based MET-levels recommended to improve and maintain health. On day 8, participants were randomly assigned to complete either the short-form International Physical Activity Questionnaire (IPAQ) or the Leisure-Time Exercise Questionnaire (LTEQ). Estimates of duration (IPAQ; N = 46) and frequency (LTEQ; N = 41) of PA were compared with those recorded by the AHR.
  
  
  RESULTS
  Bland-Altman analysis showed the mean bias between the IPAQ and AHR to be small for moderate-intensity and total PA, however the 95% limits of agreement (LOA) were wide. The mean number of moderate bouts of PA estimated by the LTEQ was similar to those derived by the AHR but the 95% LOA between the 2 measures were large.
  
  
  CONCLUSIONS
  Although self-report questionnaires may provide an approximation of PA at a population level, they may not determine whether an individual is participating in the type, intensity, and amount of PA advocated in current public health recommendations.
authors.affiliation: Dept of Health, Sport and Exercise Science Research Group, University of Bath, Bath, United Kingdom.
authors.forename: Tom
authors.initials: T
authors.lastname: Loney
authors.forename: Martyn
authors.initials: M
authors.lastname: Standage
authors.forename: Dylan
authors.initials: D
authors.lastname: Thompson
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Sebire
authors.forename: Sean
authors.initials: S
authors.lastname: Cumming
mesh_terms: D061725:Accelerometry / Q000379:methods*; D015992:Body Mass Index; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D015444:Exercise / Q000523:psychology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007899:Leisure Activities / Q000523:psychology*; D008297:Male; D055686:Metabolic Equivalent / Q000502:physiology; D011634:Public Health; D057566:Self Report; D012928:Social Desirability; D013334:Students / Q000523:psychology* / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D006113:United Kingdom; D055105:Waist Circumference; D055815:Young Adult