Date of Award


Document Type

Open Access Thesis




College of Arts and Sciences

First Advisor

Nicole Zarrett


Although research suggests there is a bidirectional relation between Physical Activity (PA) and internalizing symptomology, there are inconsistencies in the literature regarding this relation for early adolescents and little research exists that investigates potential moderators that may account for these discrepancies in underserved (i.e. low SES and minority status) populations. The current study was the first to utilize a Self-Determination Theory (SDT) framework to investigate the main effects five key motivations to exercise and their moderating effects between PA and internalizing problems in an underserved sample of early adolescents (N = 167; M age = 12.19 years; 58.1% female and 73% African-American). These motivations were compiled into composite Intrinsic and Extrinsic Motivation Scales and assessed individually using hierarchical linear regression models. Moderate-to-vigorous physical activity (MVPA) was measured using omni-directional accelerometers and multiple imputations were used to account for missing data. Results showed that MVPA was only protective against internalizing problems when intrinsic motivations were high and had iatrogenic effects when intrinsic motivations are low. There was also a main effect for motivations whereby intrinsic motivations were negatively related to internalizing problems and extrinsic motivations were positively related. Exploratory analyses further delineated the effects of motivational orientations to exercise and identified the need for further investigation into social and fitness/health motivations for exercise to gain a more nuanced understanding of these constructs. The findings in the study can be used to guide the development of interventions targeting underserved populations during the critical early adolescent years and emphasize the importance of assessing for motivations to exercise.