title: An exploratory study of seasonality and preschoolers' physical activity engagement.
abstract: BACKGROUND
  While there is an emerging body of literature showing variations in physical activity between seasons, further investigation is needed to better understand this association in preschool-age children. This study was designed to examine seasonal variation from fall to winter in physical activity among preschoolers.
  
  
  METHODS
  Forty-six preschool children from 2 preschools in a large Midwestern Metropolitan area completed weekly habitual physical activity measures in both fall and following winter. The habitual physical activity was quantified with the GT1M Actigraph uniaxial accelerometer. To determine seasonal differences in physical activity, a series of paired sample t tests were conducted.
  
  
  RESULTS
  Although overall physical activity level declined in winter, the magnitude of seasonality effects seem varied in terms of contexts. Compared with the decline during after-school time and during weekends, the differences in physical activity across the 2 seasons were much less evident during the time attending preschool and during weekdays.
  
  
  CONCLUSIONS
  Seasonality in physical activity can be moderated by other contextual factors, such as preschool policies and curriculum. Preschools may serve as a major battlefield for fighting against physical inactivity and obesity during childhood due to their practical controllability.
authors.affiliation: Dept of Kinesiology, Health, and Sport Studies, Wayne State University, Detroit, MI.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.forename: Gwen
authors.initials: G
authors.lastname: Alexander
authors.forename: Sharon
authors.initials: S
authors.lastname: Milberger
authors.forename: Kai-Lin C
authors.initials: KL
authors.lastname: Jen
mesh_terms: D061725:Accelerometry / Q000706:statistics & numerical data*; D002675:Child, Preschool; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000517:prevention & control; D012574:Schools; D012621:Seasons; D012959:Socioeconomic Factors; D013997:Time Factors; D014481:United States; D014505:Urban Population