AU - Asa-kohnefroody, Zahra AU - Peyman, Nooshin AU - Ghodsikhah, Fatima AU - Shakeri-Nejad, Ghoratollah TI - The Effect of Education Based on Planned Behavior Theory on Physical Activity of High School Girls PT - JOURNAL ARTICLE TA - Iran-J-Health-Educ-Health-Promot JN - Iran-J-Health-Educ-Health-Promot VO - 8 VI - 3 IP - 3 4099 - http://journal.ihepsa.ir/article-1-1336-en.html 4100 - http://journal.ihepsa.ir/article-1-1336-en.pdf SO - Iran-J-Health-Educ-Health-Promot 3 ABĀ  - Background and Objective: Regular physical activity is one of the components of a healthy lifestyle that improves public health, reduces burden of disease and medical costs in societies. Mashhad high school girl students were recruited . Materials and Methods: This quasi-experimental study was performed on 68 high school girl students in Mashhad. After determining the needs, educational intervention was conducted within the framework of the theory of planned behavior in the respective schools. Data were collected in three stages before and immediately after three months of educational intervention by Planned Behavioral Questionnaire and International Physical Activity Questionnaire (IPAQ) by SPSS 16 software. Mann-Whitney, regression and duplicate data analyzes were used in data analysis. Results: The findings showed that there was a significant difference in the mean scores of planned behavior theory structures in the experimental group compared to the control group after the educational intervention. Also, the level of physical activity of the girls increased after the intervention compared to before the intervention. However, these changes were not significant due to research limitation (p <0. 05) Conclusion: the implementation of educational program based on the theory of planned behavior through increasing attitudes, subjective norms and behavioral intention along with creating the necessary infrastructure to create behavior can have a positive impact on promoting adolescent girls' tendency. To have physical activity CP - IRAN IN - Mashhad University of Medical Sciences School of Health, Department of Health Education LG - eng PB - Iran-J-Health-Educ-Health-Promot PG - 210 PT - Research YR - 2020