title: School related factors and 1yr change in physical activity amongst 9-11 year old English schoolchildren.
abstract: BACKGROUND
  Activity levels are known to decline with age and there is growing evidence of associations between the school environment and physical activity. In this study we investigated how objectively measured one-year changes in physical activity may be associated with school-related factors in 9- to 10-year-old British children.
  
  
  METHODS
  Data were analysed from 839 children attending 89 schools in the SPEEDY (Sport, Physical Activity, and Eating behaviours: Environmental Determinants in Young People) study. Outcomes variables were one year changes in objectively measured sedentary, moderate, and vigorous physical activity, with baseline measures taken when the children were 9-10 years old. School characteristics hypothesised to be associated with change in physical activity were identified from questionnaires, grounds audits, and computer mapping. Associations were examined using simple and multivariable multilevel regression models for both school (9 am - 3 pm) and travel (8-9 am and 3-4 pm) time.
  
  
  RESULTS
  Significant associations during school time included the length of the morning break which was found to be supportive of moderate (β coefficient: 0.68 [p: 0.003]) and vigorous (β coefficient: 0.52 [p: 0.002]) activities and helps to prevent adverse changes in sedentary time (β coefficient: -2.52 [p: 0.001]). During travel time, positive associations were found between the presence of safe places to cross roads around the school and changes in moderate (β coefficient: 0.83 [p:0.022]) and vigorous (β coefficient: 0.56 [p:0.001]) activity, as well as sedentary time (β coefficient: -1.61 [p:0.005]).
  
  
  CONCLUSIONS
  This study suggests that having longer morning school breaks and providing road safety features such as cycling infrastructure, a crossing guard, and safe places for children to cross the road may have a role to play in supporting the maintenance of moderate and vigorous activity behaviours, and preventing the development of sedentary behaviours in children.
authors.affiliation: Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Section F, PO Box 196, Groningen 9700 AD, The Netherlands.
authors.forename: Joyce A
authors.initials: JA
authors.lastname: Mantjes
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Jones
authors.forename: Kirsten
authors.initials: K
authors.lastname: Corder
authors.forename: Natalia R
authors.initials: NR
authors.lastname: Jones
authors.forename: Flo
authors.initials: F
authors.lastname: Harrison
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Griffin
authors.forename: Esther M F
authors.initials: EM
authors.lastname: van Sluijs
mesh_terms: D001642:Bicycling; D002648:Child; D002652:Child Behavior; D004739:England; D004777:Environment; D005006:Ethnicity; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D055361:Multilevel Analysis; D012449:Safety; D012574:Schools; D057185:Sedentary Behavior; D013177:Sports; D011795:Surveys and Questionnaires; D016138:Walking