Date of Award


Degree Type


Degree Name

Doctor of Philosophy



Major Professor

David F. Cihak

Committee Members

Marion Coleman-Lopatic, Dawn P. Coe, Tara Moore


Regular physical activity can decrease the likelihood of being overweight or obese as well as other negative health outcomes. Adults with intellectual and developmental disabilities (I/DD) are more likely to be obese, less likely to be physically active, and at greater risk for health conditions and disease. Thus, there is a need for interventions that aim to increase the physical activity levels of adults with I/DD. However, interventions and related research in this field are limited. The purpose of this dissertation was to examine two independent single-subject design interventions that incorporated the use of wearable technology, a Fitbit, in order to improve physical activity levels of young adults with I/DD. Chapter 1 provided an overview of the theoretical foundations behind motivation, in particular, self-determination theory, as well as how it is related to fitness and physical activity. Common barriers that people with I/DD face when participating in physical activity are explored, as well as, self-management as a strategy for increasing physical activity. Chapter 2 evaluated the effects of a goal-setting intervention on the physical activity levels of college students with I/DD. It was implemented as a part of a singlesubject changing criterion design, where students set step count goals for each phase based on previous averages. Results indicated that participants consistently increased the number of steps taken across consecutive phases and were able to achieve greater consistency in step counts over time. Chapter 3 examined the effects of a social reinforcement intervention via a single-subject withdrawal/reversal design on the activity levels of college students with I/DD as measured by daily steps. This intervention incorporated social reinforcement by peer mentors within the Fitbit app. The intervention was effective, as all participants increased average step counts during intervention weeks. Chapter 4 discussed results of both studies as they pertain to the current literature on wearable technology to improve activity levels, self-management and goal setting in relation to health, fitness, and physical activity, and social reinforcement in physical activity for people with I/DD. Conclusions are discussed within the framework of self-determination theory. Limitations, implications, and recommendations for future research are also presented.

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