title: Outdoor Temperature, Precipitation, and Wind Speed Affect Physical Activity Levels in Children: A Longitudinal Cohort Study.
abstract: OBJECTIVE
  Evaluate effects of local weather conditions on physical activity in early childhood.
  
  
  METHODS
  Longitudinal prospective cohort study of 372 children, 3 years old at enrollment, drawn from a major US metropolitan community. Accelerometer-measured (RT3) physical activity was collected every 4 months over 5 years and matched with daily weather measures: day length, heating/cooling degrees (degrees mean temperature < 65°F or ≥ 65°F, respectively), wind, and precipitation. Mixed regression analyses, adjusted for repeated measures, were used to test the relationship between weather and physical activity.
  
  
  RESULTS
  Precipitation and wind speed were negatively associated with total physical activity and moderate-vigorous physical activity (P < .0001). Heating and cooling degrees were negatively associated with total physical activity and moderate-vigorous physical activity and positively associated with inactivity (all P < .0001), independent of age, sex, race, BMI, day length, wind, and precipitation. For every 10 additional heating degrees there was a 5-minute daily reduction in moderate-vigorous physical activity. For every additional 10 cooling degrees there was a 17-minute reduction in moderate-to-vigorous physical activity.
  
  
  CONCLUSIONS
  Inclement weather (higher/lower temperature, greater wind speed, more rain/snow) is associated with less physical activity in young children. These deleterious effects should be considered when planning physical activity research, interventions, and policies.
authors.affiliation: Division of Sports Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Edwards
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Myer
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Kalkwarf
authors.forename: Jessica G
authors.initials: JG
authors.lastname: Woo
authors.forename: Philip R
authors.initials: PR
authors.lastname: Khoury
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Hewett
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Daniels
mesh_terms: D061725:Accelerometry / Q000379:methods; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011891:Rain; D012044:Regression Analysis; D012621:Seasons; D013696:Temperature; D014919:Wind