title: Factors associated with physical activity among Canadian high school students.
abstract: OBJECTIVE
  Identifying multi-level factors affecting physical activity (PA) levels among adolescents is essential to increasing activity to promote health within this population. This study examines the associations between PA and 11 independent factors among Manitoba high school students.
  
  
  METHODS
  The sample included 31,202 grade 9-12 students who completed the Manitoba Youth Health Survey. Associations between PA and independent factors were examined separately and through multivariate regression. Analyses were stratified by gender.
  
  
  RESULTS
  Perception of athletic ability, school location, parental encouragement and number of active friends were strong predictors of activity for moderately active and active males and females. Grade was a significant predictor of PA for females at both levels of activity but only significant for males when comparing active to inactive students. Perception of schoolwork and means of transport were minimally associated with PA.
  
  
  CONCLUSIONS
  Results highlight the importance of targeting multiple levels of influence to increase PA among youth. Programs should focus on older students, females and those who are inactive or moderately active. In addition, social modeling of PA and increasing self-efficacy around activity should be encouraged.
authors.affiliation: Epidemiology and Cancer Registry, CancerCare Manitoba, RM OG008, 409 Tache Avenue, Winnipeg, MB, R2H 2A6, Canada. carly.leggett@cancercare.mb.ca
authors.forename: Carly
authors.initials: C
authors.lastname: Leggett
authors.forename: Melinda
authors.initials: M
authors.lastname: Irwin
authors.forename: Jane
authors.initials: J
authors.lastname: Griffith
authors.forename: Lin
authors.initials: L
authors.lastname: Xue
authors.forename: Katherine
authors.initials: K
authors.lastname: Fradette
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D009043:Motor Activity; D015999:Multivariate Analysis; D012574:Schools / Q000706:statistics & numerical data; D012737:Sex Factors; D013334:Students / Q000706:statistics & numerical data*; D055815:Young Adult