title: Step based physical activity guidelines for preschool-aged children.
abstract: OBJECTIVE
  Public health organizations recommend that preschool-aged children accumulate at least 3h of physical activity (PA) daily. Objective monitoring using pedometers offers an opportunity to measure preschooler's PA and assess compliance with this recommendation. The purpose of this study was to derive step-based recommendations consistent with the 3h PA recommendation for preschool-aged children.
  
  
  METHODS
  The study sample comprised 916 preschool-aged children, aged 3 to 6years (mean age=5.0±0.8years). Children were recruited from kindergartens located in Portugal, between 2009 and 2013. Children wore an ActiGraph GT1M accelerometer that measured PA intensity and steps per day simultaneously over a 7-day monitoring period. Receiver operating characteristic (ROC) curve analysis was used to identify the daily step count threshold associated with meeting the daily 3hour PA recommendation.
  
  
  RESULTS
  A significant correlation was observed between minutes of total PA and steps per day (r=0.76, p<0.001). The optimal step count for ≥3h of total PA was 9099 steps per day (sensitivity (90%) and specificity (66%)) with area under the ROC curve=0.86 (95% CI: 0.84 to 0.88).
  
  
  CONCLUSIONS
  Preschool-aged children who accumulate less than 9000 steps per day may be considered Insufficiently Active.
authors.affiliation: Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal; Department of Sport Science. High School of Education, Polytechnic Institute of Oporto, Portugal. Electronic address: susanavale@hotmail.com.
authors.forename: Susana
authors.initials: S
authors.lastname: Vale
authors.affiliation: School of Exercise and Nutrition Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors.forename: Stewart G
authors.initials: SG
authors.lastname: Trost
authors.affiliation: Faculty of Health and Life Sciences, Coventry University, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Duncan
authors.affiliation: Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Mota
mesh_terms: D056044:Actigraphy / Q000295:instrumentation / Q000379:methods*; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011174:Portugal; D012372:ROC Curve; D017678:Sex Distribution; D013997:Time Factors
keywords: Physical activity guidelines; Preschool children; Steps