en Health Promotion Health Promotion پژوهشي Original Article <div><span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:normal"><b>Background</b>: Physical activity during retirement is one of the health promotion determinants in this group. This study was conducted to determine the effect of an educational intervention based on the health action process approach (HAPA) on the levels of physical activity among retired female employees.</span><br> <span style="line-height:normal"><b>Methods</b>: This quasi-experimental study was conducted among 97 retired women, selected through a simple random sampling technique, and divided into two groups. The primary instruments employed for data collection included the International Standard Physical Activity Behavior Questionnaire (IPAQ) and a researcher-made questionnaire based on the HAPA. Data analysis was performed using SPSS version 20, incorporating a range of statistical tests, namely Spearman&#39;s correlation, independent and paired t-tests, the Willcoxon signed-rank test, and the Mann-Whitney U test.</span><br> <span style="line-height:normal"><b>Results</b>: After the educational intervention, the average score of different levels of physical activity has increased significantly (<i>p </i>< 0.05). In addition, three months after the intervention, the score of all the constructs of the HAPA model except for the structure of action planning and coping planning, was significantly increased (<i>p</i> < 0.05).</span><br> <span style="line-height:normal"><b>Conclusion</b>: The implementation of an intervention based on the HAPA can improve the level of physical activity in middle-aged women. Therefore, it is suggested that future studies based on this approach be conducted in other target groups to promote physical activity.</span></span></span></div> Health action process approach model (HAPA), Physical activity, Retirement, Social support, Self-efficacy, 201 209 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-579-2&slc_lang=en&sid=1 Hooriyeh Mirzaeimoghadam mirzaeihouriyeh@gmail.com 100319475328460013367 0009000542435314 No Department of Health Education and Health Promotion, Faculty of Health, Student Research Committee, Rafsanjan University of Medical Sciences, Rafsanjan, Iran. Mostafa Nasirzadeh mnasirzadeh13@yahoo.com 100319475328460013368 0000000309344697 No Department of Health Education and Health Promotion, School of Health, Occupational Health and Safety Research Center, NICICO, World Safety Organization and Rafsanjan University of Medical Sciences, Rafsanjan, Iran. Ahmadreza Sayadi sayadiahmad@yahoo.com 100319475328460013369 0000000253115173 No Department of Psychiatric Nursing, School of Nursing and Midwifery, Socially Determinants of Health, Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran. Mahdi Abdolkarimi abdolkarimi@rums.ac.ir 100319475328460013370 0000000227812821 Yes Department of Health Education and Health Promotion, School of Health, Geriatric Care Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.