Longitudinal Changes in Beliefs by Stage of Physical Activity Adoption in Iranian Girls

Background: The aims of this study were to examine the relationships among physical activity (PA)-related beliefs and to determine to what extent Iranian adolescents in different stages of PA adoption differ in perceived benefits and barriers during a 3-year transition from junior high school to high school. Methods: Data were collected from female adolescents in 2010 (N?=?558), of whom 412 provided follow-up data in 2013. One-way analysis of variance and logistic regression were conducted for statistical analysis. Results: Participants in the action and maintenance stages reported the greatest agreement with benefits. Pre-contemplators were about 4 times more likely to cite "not enough time" than preparers (OR?=?3.95). Pre-contemplators were over 4 times more likely to cite not liking exercise than those in action and maintenance stages at baseline (OR?=?4.32 and 4.85), a finding which was maintained at follow-up (OR?=?3.66 and 8.65). Conclusions: These findings could help with the creation of interventions tailored to encourage pre-contemplators to progress toward adoption of PA. Providing transportation supports, enhancing time management, and mitigating boredom may be helpful strategies either to prevent relapse in adoption stages or to move females in early stages of change toward action and maintenance.