title: The utility of the Digi-walker step counter to assess daily physical activity patterns.
abstract: OBJECTIVE
  The Digi-Walker step counter is a promising and cost-effective tool to measure physical activity under free-living conditions. Two specific studies were conducted to evaluate the number of steps required to meet current physical activity guidelines.
  
  
  METHODS
  Thirty-one adults (17 men, 14 women) served as participants. In study 1, we determined the number of steps to complete a mile under two different conditions and three paces. In study 2, we conducted a field trial to examine the relationship between daily step counts and other indices of physical activity. Participants in this study wore a Digi-Walker for 2 consecutive weeks and completed the 7-d physical activity recall (PAR) after each week.
  
  
  RESULTS
  In study 1, there were no differences in step counts by site, but steps were inversely related to pace, with values ranging from 1330 to 1996. Individual step counts at a specific pace were negatively correlated with height, weight, leg length, and stride length and were positively correlated with body fatness. In study 2, participants had average daily step counts of 11,603 when structured vigorous activity was included and 8265 when only light and moderate activity were measured. Modest correlations were found between step counts and estimated energy expenditure. Similar correlations were observed when step counts were related to minutes of activity per day and minutes of sitting per day.
  
  
  CONCLUSIONS
  Pedometers provide a useful indicator of daily step counts but variability in activity patterns make it difficult to establish step count guidelines that correspond with other public health guidelines.
authors.affiliation: Health and Human Performance Department, Iowa State University, Ames 50011, USA. gwelk@iastate.edu
authors.forename: G J
authors.initials: GJ
authors.lastname: Welk
authors.forename: J A
authors.initials: JA
authors.lastname: Differding
authors.forename: R W
authors.initials: RW
authors.lastname: Thompson
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
authors.forename: J
authors.initials: J
authors.lastname: Dziura
authors.forename: P
authors.initials: P
authors.lastname: Hart
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D003362:Cost-Benefit Analysis; D005080:Exercise Test / Q000295:instrumentation; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D010809:Physical Fitness; D012680:Sensitivity and Specificity; D016138:Walking