Thesis (Ph.D.) - Indiana University, School of Public Health, 2019Obesity among children is a significant health problem that likely will persist without intervention. Incorporating 60 minutes of physical activity daily into children’s lives with is important in obesity prevention. This study investigated physical activity levels of elementary students along with family members’ and friends’ encouragement and participation in physical activity with them. The sample included 180 5th and 6th grade students (101 girls and 79 boys), ages 10-13, from seven elementary schools in one Indiana school district. Pearson correlation was used to show the relationship between variables and multiple linear regression (forward entry) analysis was executed to investigate the ability of beliefs (attitudes and self-efficacy), social support factors (source and type), and perceived health to predict physical activity levels. Via an online questionnaire, students’ self-reported demographic data, participation in physical activity, encouragement from friends and family to be physically active, beliefs about physical activity, and perceptions of personal health status. Social support, attitudes, self-efficacy and perceived health were positively related to physical activity (p<0.001). Findings support the importance of beliefs, friend and family member encouragement and participation in physical activities with children. Future research should focus on testing strategies for strengthening both.