title: Determinants of physical activity and sedentary behaviour in young people: a review and quality synthesis of prospective studies.
abstract: OBJECTIVE
  The aim of this systematic review was to summarise and update the existing literature on determinants of physical activity and sedentary behaviour in young people, considering the methodological quality of the studies.
  
  
  METHODS
  Prospective studies were identified from searches in PubMed and PsycINFO, from April 2004 through November 2010. The authors included studies investigating the association between determinants of overall physical (in)activity and/or sedentary behaviour in healthy children or adolescents. When a determinant was investigated for its association with physical (in)activity and sedentary behaviour assessed between ages of 4-12, or mean age ≤12, it was classified as 'child determinant'. When a determinant was investigated for its association with physical activity and sedentary behaviour assessed between ages of 13-18 or mean age >12, it was classified as 'adolescent determinant'. Included articles were scored on their methodological quality and a best-evidence synthesis was applied to summarise the results.
  
  
  RESULTS
  The authors identified 30 papers, of which seven were of high methodological quality. Intention was found as a determinant of children's physical activity. Determinants of adolescents' physical activity were age (ie, older children were more active), ethnicity (ie, being of African--American descent determined being less physically active) and planning. The authors found insufficient evidence for determinants of sedentary behaviour.
  
  
  CONCLUSIONS
  Studies on determinants of physical activity and sedentary behaviour were in general of poor methodological quality. To develop long-term effective interventions that increase physical activity and decrease time spent in sedentary behaviours in young people, we need more high quality prospective evidence on the determinants of these behaviours.
authors.affiliation: Department of Public and Occupational Health, EMGO+ Institute, VU University Medical Center, van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
authors.forename: Léonie
authors.initials: L
authors.lastname: Uijtdewilligen
authors.forename: Joske
authors.initials: J
authors.lastname: Nauta
authors.forename: Amika S
authors.initials: AS
authors.lastname: Singh
authors.forename: Willem
authors.initials: W
authors.lastname: van Mechelen
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
authors.forename: Klazine
authors.initials: K
authors.lastname: van der Horst
authors.forename: Mai J M
authors.initials: MJ
authors.lastname: Chinapaw
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003625:Data Collection / Q000592:standards; D015444:Exercise / Q000502:physiology*; D005260:Female; D006293:Health Promotion; D006801:Humans; D008297:Male; D011446:Prospective Studies; D057185:Sedentary Behavior