title: Effect of peers and friends on youth physical activity and motivation to be physically active.
abstract: OBJECTIVE
  To test whether the presence of a peer or a friend increases the motivation to be physically active in overweight and non-overweight youth in a laboratory setting.
  
  
  METHODS
  Youth motivation to be physically active as a function of the social context was measured using a computerized relative reinforcing value task to earn points exchangeable for physical and/or sedentary activities.
  
  
  RESULTS
  The presence of a friend (p<.001) increased youth's; motivation to be physically active. The presence of a peer increased overweight youth's; motivation to be physically active, whereas this was not the case for lean youth (p=.47). Participants biked a greater distance in the presence of a friend than when alone (p<.001). Overweight youth biked a greater distance in the presence of a peer than when alone, while this was not the case for lean youth (p=.23).
  
  
  CONCLUSIONS
  Friendships may increase youth's motivation to engage in physical activity and promote greater physical activity in non-overweight and overweight youth.
authors.affiliation: Department of Pediatrics, Division of Behavioral Medicine, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214-3000, USA. ssalvy@buffalo.edu
authors.forename: Sarah-Jeanne
authors.initials: SJ
authors.lastname: Salvy
authors.forename: James N
authors.initials: JN
authors.lastname: Roemmich
authors.forename: Julie C
authors.initials: JC
authors.lastname: Bowker
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Romero
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Stadler
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Epstein
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D033062:Friends; D006801:Humans; D008297:Male; D009042:Motivation; D009043:Motor Activity; D009765:Obesity / Q000517:prevention & control*; D010379:Peer Group