title: Understanding exercise behavior among New Zealand adolescents: a test of the transtheoretical.
abstract: OBJECTIVE
  To test the utility of applying the Transtheoretical Model (TTM) to adolescent exercise behavior. The purpose of Study 1 was a replication study to examine whether the TTM could predict exercise stage readiness in adolescents. The purpose of Study 2 was to test the model's internal validity to predict exercise stage transition.
  
  
  METHODS
  For Study 1, students (n = 3972) from 13 high schools completed questionnaires corresponding the variables in the TTM (i.e., stage of exercise change, processes of change, self-efficacy and decisional balance). For Study 2, 1434 of those participants completed the stage of exercise change questionnaire 6 months later. These data were used to establish an exercise stage transition profile.
  
  
  RESULTS
  Results from Study 1 showed large effects for self-efficacy, decisional balance and two behavioral processes (i.e., counter-conditioning and self-liberation). Study 2 showed that all TTM construct significantly predicted exercise stage transition. Large effects were found for the same variables as in Study 1.
  
  
  CONCLUSIONS
  The TTM is a useful framework for understanding both exercise stage readiness and exercise stage transition in an adolescent population.
authors.affiliation: Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand. h.prapavessis@auckland.ac.nz
authors.forename: Harry
authors.initials: H
authors.lastname: Prapavessis
authors.forename: Ralph
authors.initials: R
authors.lastname: Maddison
authors.forename: Fiona
authors.initials: F
authors.lastname: Brading
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D003657:Decision Making; D015444:Exercise / Q000523:psychology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008960:Models, Psychological; D009520:New Zealand; D011594:Psychometrics / Q000295:instrumentation*; D020377:Self Efficacy; D013334:Students / Q000523:psychology; D011795:Surveys and Questionnaires