International Journal of Preventive Medicine (Int J Prev Med)2008-7802112012070112829ENDepartment of Health Promotion and Education, School of Public Health, Tehran University of Medical Sciences, Tehran, IranDepartment of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, IranDepartment of Health Promotion and Education, School of Public Health, Tehran University of Medical Sciences and Health Center for Community-Based Participatory Research, Tehran, Iran,Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, IranGeneral Practitioner, School of Medicine, Isfahan University of Medical Sciences, Isfahan, IraIntegrative Functional Gastroenterology Research Center, Isfahan University of Medical Sciences and Psychosomatic Research Center, Isfahan University of Medical Sciences, Isfahan, Iran20120701<p><strong>Aims: </strong>The present study focuses on comparing the effects of home-based (HB) and group-based (GB) physical activity on mental health in a sample of older adults in Shahr-e-kord.</p> <p><strong>Methods: </strong>In this quasi-experimental study, a twice-weekly physical activity program for 2 months was provided either individually at home or in a group format for 181 people who were divided into two groups (HB and GB). The outcome, mental health, was measured with the 28-item General Health Questionnaire (GHQ-28).</p> <p><strong>Results: </strong>Mental health status improved after participation in the physical activity program. The decrease in GHQ-28 total score in GB group, 3 months after intervention, was 3.61 &plusmn; 2.28 (<em>P </em>&lt; 0.001). In HB group, this reduction was 1.20 &plusmn; 2.32 during the same period (<em>P </em>&lt; 0.001). The difference of these &ldquo;before&ndash;after differences&rdquo; between the two groups in the GHQ-28 and all its subscales was statistically significant (<em>P </em>&lt; 0.001). Also, the effects of GB physical activity on mental health compared with HB physical activity, adjusted for related baseline variables, were significant.</p> <p><strong>Conclusions: </strong>These findings reveal the probable effects of GB rather than HB physical activity on mental health among the elderly.</p> <strong>Keywords: </strong>Elderly, group-based physical activity, home-based physical activity, mental healthhttp://ijpm.mui.ac.ir/index.php/ijpm/article/view/764http://ijpm.mui.ac.ir/index.php/ijpm/article/download/764/1288