Physical Activity Promotion in Schools Using Theoretically Designed Mobile Phone Application

Regular physical activity for adolescents has many health benefits, many of which also affect adulthood. Physical activity is a behavior that requires planning and choosing an appropriate educational method, model, or theory. However, mobile phone applications are known as a suitable method to increase physical activity according to the guidelines. This study aims to increase physical activity in female students based on the theory of planned behavior using mobile phone applications. This quasi-experimental study was implemented on 220 high school students (110 people in each group). The samples were selected by a multi-stage cluster method and their information was collected by the International Physical Activity Questionnaire (IPAQ) and the Theory of Planned Behavior (TPB) questionnaire whose validity and reliability were confirmed. The intervention group received 8 sessions of education through a mobile phone application that was designed by the constructs of the theory of planned behavior. The samples were evaluated in three stages, through a pre-test, post-test, and two-month follow-up. The results showed a significant difference in the post-test and two months after the intervention between intervention and control groups in terms of attitude, perceived behavioral control, intention, and physical activity. There was a significant difference between intervention and control groups in subjective norms in the post-test, but there was no significant difference in the two-month follow-up compared to the post-test (P = 0.08). An educational intervention based on the theory of planned behavior using mobile phone applications led to an increase in the physical activity of girl high school students. However, to determine the full effectiveness of this study, it is recommended to implement this intervention in all schools.