title: Initial insight into why physical activity may help prevent adolescent smoking uptake.
abstract: BACKGROUND
  Whereas research supports the importance of regular physical activity to decrease the likelihood of smoking uptake, the mechanisms accounting for this relationship are poorly understood. We sought to determine whether the enjoyment or reward derived from physical activity is one mechanism underlying the relationship between smoking and physical activity.
  
  
  METHODS
  The sample was composed of 1374 adolescents participating in a prospective longitudinal survey study of health behaviors. Variables were measured via self-report every six months for eight waves of data spanning four years.
  
  
  RESULTS
  An associative processes latent growth curve model revealed a significant and negative indirect effect of baseline physical activity on baseline smoking through baseline physical activity reward (b(indirect)=-.18, z=-3.11, p=.002; 95% CI=-.29, -.07). Similarly, there was a significant and negative indirect effect of physical activity trend on smoking trend through physical activity reward trend (b(indirect)=-.16, z=-2.09, p=.04; 95% CI=-.30, -.01). The effect of physical activity on smoking at baseline and across time was completely mediated by physical activity reward. There was less support for the idea that smoking progression was associated with reduced physical activity reward and subsequent declines in physical activity.
  
  
  CONCLUSIONS
  This study provides the first evidence implicating physical activity reward as one mechanism by which physical activity reduces the likelihood of adolescent smoking uptake. Smoking prevention interventions that promote physical activity and target physical activity enjoyment may have an important impact on adolescent smoking initiation and progression.
authors.affiliation: Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, United States. Electronic address: audrain@mail.med.upenn.edu.
authors.forename: Janet
authors.initials: J
authors.lastname: Audrain-McGovern
authors.forename: Daniel
authors.initials: D
authors.lastname: Rodriguez
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Cuevas
authors.forename: Joseph
authors.initials: J
authors.lastname: Sass
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology* / Q000523:psychology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011446:Prospective Studies; D012201:Reward; D057566:Self Report; D012907:Smoking / Q000523:psychology*; D000074606:Smoking Prevention
keywords: Adolescents; Physical activity; Physical activity enjoyment; Prevention; Smoking