Date of Award

Fall 2021

Document Type

Open Access Thesis



First Advisor

Nicole Zarrett


Rates of youth physical activity (PA) drastically decrease during adolescence, with a steeper decline for adolescent girls (Belcher et al., 2010; CDC, 2010). Although afterschool programs (ASPs) have been identified as an ideal context for promoting youth PA, ASPs vary in quality with girls having the highest rates of inactivity (Zarrett et al., 2018). Theory and previous studies have identified social-motivational climate-based factors within ASPs that are critical for promoting adolescents’ PA (Basch, 2011; Eccles et al., 2002; Zarrett et al., 2013, 2015). The present study first examines gender differences in the social-motivational quality of middle school ASPs for promoting youth PA. Second, we examine the impact of a social-motivational climate-based intervention on changes in key social-motivational mechanisms and youth PA accrual, with a primary focus on whether girls and boys benefit equally from the intervention.

Participants included 153 youth ages 10-16 (M = 12.27, SD = 1.076) 153 youth across six underserved (low-income, minority status) middle school ASPs (3 intervention; 3 waitlist control; 56% female; 70% African American). The 10-week randomized controlled feasibility trial targeted multiple levels of the social-motivational climate to improve PA engagement, including staff behaviors, peer-relations, program structure, and activities offered. The current study reports findings from the systematic observations of ASPs using SOCARP (Ridgers et al., 2010) and the MCOT-PA (Zarrett et al., 2015).

Preliminary results indicate that at baseline, boys were significantly more engaged in PA and were more likely to experience a higher quality social-motivational climate for PA compared to girls. Girls in the intervention experienced significant increases in PA, peer interactions, staff interactions, and social-motivational climate factors compared to girls in the control at post-intervention. However, boys in the intervention group had more significant differences in these key social-motivational determinants for PA engagement at post-intervention. Findings illustrate gender differences in youth social experiences when engaging in PA within ASPs. Implications for how to foster increases in girls’ PA within ASPs and other youth settings by targeting social-motivational supports will be discussed.