title: Greenspace and children's physical activity: a GPS/GIS analysis of the PEACH project.
abstract: OBJECTIVE
  To quantify the volume and intensity of children's physical activity after school in greenspace and elsewhere.
  
  
  METHODS
  Data were collected between 2006 and 2008 from 1,307 children aged 10-11 in Bristol, UK. Accelerometers and Global Positioning System receivers measured activity and location every 10 s (epoch) after school for four days. Data were mapped in a Geographic Information System with a greenspace dataset. Activity volume (accelerometer counts per minute), time in moderate-vigorous physical activity (MVPA), and the odds of an epoch being MVPA (using logistic regression) were compared for greenspace, non-greenspace and indoors.
  
  
  RESULTS
  13% of monitored time was spent outdoors (2% in greenspace), during which time 30% of activity volume and 35% of MVPA was accumulated. 7% of boys' activity volume and 9% of MVPA were in greenspace with girls slightly lower (5% and 6% respectively). The odds of an epoch being MVPA in greenspace relative to outdoor non-greenspace was 1.37 (95% CI 1.22-1.53) for boys and 1.08 (95% CI 0.95-1.22) for girls.
  
  
  CONCLUSIONS
  Most activity occurring outdoors is not in greenspace and non-green urban environments are therefore very important for children's activity. However, when boys are in greenspace, activity is more likely to be of higher intensity.
authors.affiliation: DECIPHer Centre, Department of Social Medicine, University of Bristol, Bristol, UK. benedict.wheeler@pcmd.ac.uk
authors.forename: Benedict W
authors.initials: BW
authors.lastname: Wheeler
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Cooper
authors.forename: Angie S
authors.initials: AS
authors.lastname: Page
authors.forename: Russell
authors.initials: R
authors.lastname: Jago
mesh_terms: D015992:Body Mass Index; D002648:Child; D004779:Environment Design; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009043:Motor Activity; D012044:Regression Analysis; D006113:United Kingdom