title: Can sedentary adults accurately recall the intensity of their physical activity?
abstract: BACKGROUND
  Physical activity, in particular vigorous activity (i.e., > or =6 METs), lowers mortality from chronic diseases such as cardiovascular disease (CVD). The 7-Day Physical Activity Recall (PAR), a self-administered activity log (LOG), and heart rate monitoring (HR) were used to quantify activity patterns among sedentary adults. We hypothesized that individuals in this population could accurately estimate the duration, but not the intensity, of their activity.
  
  
  METHODS
  Sedentary adults (n = 94, 47.8 +/- 7.1 years) completed two PARs 1 week apart and underwent HR monitoring while completing a LOG for 1 day during the PAR assessment interval.
  
  
  RESULTS
  The relationship between PARs (kcal. kg(-1). day(-1) ) was significant (r = 0.80, 95% CI 0.68-0.87) among individuals (n = 63) reporting "typical" activity patterns and among all individuals (n = 94) reporting "typical" and "not typical" activity patterns combined (r = 0.44, 95% CI 0.26-0.59). Quantity of moderate activity was greater (P = 0.0001) on PAR and LOG compared to that measured by HR. Quantity of hard (vigorous) activity was also greater (P = 0.019) on LOG compared to that measured by HR.
  
  
  CONCLUSIONS
  Sedentary adults tend to overestimate the intensity of their activity, specifically for moderate activity. Furthermore, the aerobic capacity of our sedentary adult sample (about 7.3 METs) suggests that the definition of a threshold intensity level of activity necessary to reduce mortality from CVD should be reexamined, because a value of > or =6 METs appears to be too high in this population.
authors.affiliation: College of Medicine, University of Florida, Gainesville 32610, USA. gduncan@ufl.edu
authors.forename: G E
authors.initials: GE
authors.lastname: Duncan
authors.forename: S J
authors.initials: SJ
authors.lastname: Sydeman
authors.forename: M G
authors.initials: MG
authors.lastname: Perri
authors.forename: M C
authors.initials: MC
authors.lastname: Limacher
authors.forename: A D
authors.initials: AD
authors.lastname: Martin
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D015444:Exercise; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000592:standards*; D011939:Mental Recall; D008875:Middle Aged; D011795:Surveys and Questionnaires / Q000592:standards*