title: Predicting the physical activity intention-behavior profiles of adopters and maintainers using three social cognition models.
abstract: BACKGROUND
  Most of the population have positive intentions to engage in physical activity (PA) but fail to act; thus, the need to understand successful translation of intention into behavior is warranted in order to focus intervention efforts.
  
  
  OBJECTIVE
  The objective of the study is to examine constructs of the transtheoretical model, theory of planned behavior, and protection motivation theory as predictors of physical activity intention-behavior profiles across 6 months in a Canadian workplace sample.
  
  
  METHODS
  Employees from three large organizations in the province of Alberta (n = 887) completed a baseline survey relating to their demographic and medical background, PA, and social-cognitive constructs. A total of 611 participants completed a second assessment 6 months later.
  
  
  RESULTS
  Participants were grouped by five profiles: nonintenders, unsuccessful adopters, successful adopters, unsuccessful maintainers, and successful maintainers. Perceived importance and concern for PA (cognitive processes, instrumental attitude, perceived severity) distinguished nonintenders from the other four profiles, self-management and self-regulation of the behavior (behavioral processes, self-efficacy) distinguished successful adopters from unsuccessful adopters, while control over constraints (cons, perceived control, self-efficacy) were the key discriminators of successful maintainers from unsuccessful maintainers.
  
  
  CONCLUSIONS
  The results provide useful information for intervention campaigns and demonstrate a need to consider adoption and maintenance profiles.
authors.affiliation: Behavioural Medicine Laboratory, Faculty of Education, University of Victoria, BC, Canada. rhodes@uvic.ca
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Rhodes
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Plotnikoff
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
mesh_terms: D000328:Adult; D005544:Forecasting; D006801:Humans; D033182:Intention; D008875:Middle Aged; D009043:Motor Activity; D010934:Planning Techniques; D011581:Psychological Tests; D011582:Psychological Theory; D017132:Workplace