effects of education based on transtheoretical model on physical activity of college students

background: educational interventions to promote physical activity are one of the health priorities. a theoretical approach to promote and maintain physical activity is the transtheoretical model (ttm). this research was conducted to determine the effects of this model on students' physical activity habits in 2011. methods: this quasi-experimental study was conducted on 200 students in two groups of intervention and control. data collection instrument was a questionnaire including personal information, stages of exercise change questionnaire (secq), self-efficacy scale (ses), and decisional balance scale (dbs). educational intervention was carried out with ttm-based group discussions and lectures. the education package included pamphlets, posters, and films. eight weeks after the last educational session, posttest data was collected. comparisons between pretest and posttest data were made using the measure of central value, mcnemar test, and paired t- test with 95% confidence intervals. findings: before the intervention, there were no statistically significant differences between the two groups in terms of marital status, mean age, and secq scores. after the intervention, secq scores of the intervention group progressed toward the active stage (p < 0.001) while no such statistical difference was detected in the control group. in addition, the intervention significantly increased the scores of dbs and ses and also the amount of physical activity. conclusion: it can be concluded that implementing educational interventions based on ttm is an effective strategy for promoting physical activity in college student.