title: The contribution of active travel to children's physical activity levels: cross-sectional results from the ALSPAC study.
abstract: OBJECTIVE
  To assess the association between active travel to school and physical activity (PA) in a large population-based sample of 11-year old children.
  
  
  METHODS
  Cross-sectional analyses using data from the Avon Longitudinal Study of Parents and Children (Bristol, UK), collected in 2002-2004. The analyses include all children providing valid data on objectively measured PA (Actigraph accelerometer), and having parent-proxy reported data on travel mode (walk, cycle, public transport, car) and distance to school (N=4688).
  
  
  RESULTS
  43.5% of children regularly walked or cycled to school (i.e. on every or most days). Compared with car travelers, walking to school was associated with 5.98 (95%CI: 3.82-8.14) more minutes of moderate-to-vigorous PA (MVPA) on weekdays in those living 0.5-1 miles from school, and with 9.77 (95%CI: 7.47-12.06) more minutes in those living at 1-5 miles. This equates to 24.6 to 40.2% of the average daily minutes of MVPA. Only modest differences were observed in those living <0.5 mile from school.
  
  
  CONCLUSIONS
  Children who regularly walk to school are more active during the week than those travelling by car, especially if the distance is >0.5 mile. Increasing participation in active travel might be a useful part of an overall strategy to increase population PA.
authors.affiliation: MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK. esther.vansluijs@mrc-epid.cam.ac.uk
authors.forename: Esther M F
authors.initials: EM
authors.lastname: van Sluijs
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Fearne
authors.forename: Calum
authors.initials: C
authors.lastname: Mattocks
authors.forename: Chris
authors.initials: C
authors.lastname: Riddoch
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Griffin
authors.forename: Andy
authors.initials: A
authors.lastname: Ness
mesh_terms: D000054:Acceleration; D001642:Bicycling / Q000502:physiology; D002648:Child; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D006293:Health Promotion; D006801:Humans; D008297:Male; D009043:Motor Activity; D012574:Schools; D013334:Students; D013997:Time Factors; D014186:Transportation / Q000379:methods*; D006113:United Kingdom; D016138:Walking / Q000502:physiology