Background Out-of-school time (OST) organized group youth activities (e.g., afterschool programs, clubs) can reduce health inequalities by increasing physical activity (PA). However, unlike youth sport, PA is not the primary focus of many organized activities. This study examined the association between rural childrens demographic factors and OST non-sport organized activity participation and the differences between these factors and PA. Methods During Spring 2019, children (
n=418 3rd 6th graders, aged 812 years) enrolled in two rural Midwestern public schools in the United States completed the Youth Activity Profile (YAP) and supplemental National Survey of Childrens Health 20172018 survey questions assessing OST organized activity participation as part of the Wellscapes Project, a type 3 hybrid implementation-effectiveness community randomized trial. A subsample of 235 children (males, n=117; females, n=118) provided parental/guardian consent to pair YAP results with student enrollment records. Average OST moderate-to-vigorous PA (MVPA) per weekday and weekend days was estimated using an algorithm converting raw YAP scores into minutes of MVPA. Mixed models with community as a random effect examined main effects and interactions of grade, sex, and family income on OST non-sport organized activity participation and these factors and participation on MVPA. Results Most children (73.2%) participated in an OST non-sport organized activity. Males were less likely to participate in organized activities than females (OR=0.38, 95% CI=0.200.73, p=0.004). Females and 6th graders reported lower OST MVPA on weekdays and weekends than comparison groups ( p<0.001). Males with lower family income accumulated significantly fewer minutes of MVPA on weekdays (meandiff = -4.72.0 minutes) and weekends (meandiff = -8.93.8 minutes) compared with males with higher family income ( p<0.05 ). Conclusions Many rural children participated in OST organized activities regardless of grade and family income. However, there were inequalities in organized activity participation and OST weekday and weekend MVPA by demographic factors, including grade, sex, and family income. Designing OST organized activity settings to include PA may aid in reducing PA inequalities and promoting health equity.