Date of Award

Spring 2020

Document Type

Open Access Dissertation


Exercise Science

First Advisor

Delia West


INTRODUCTION: Previous studies have shown a relationship between sedentary behavior as an independent and novel risk factor for high blood pressure. However, most of the evidence comes from cross-sectional and experimental studies, with only a few studies examining whether blood pressure is improved in individuals participating in a behavioral intervention. None of these studies utilized mHealth approaches, which hold potential for behavioral interventions, and none have focused on individuals with hypertension as a part of their target population. Therefore, the purpose of the dissertation was to 1) Examine the efficacy of a smartphone-mediated multi-component sedentary behavior reduction intervention for individuals with overweight or obesity and with or without hypertension, 2) Determine whether a change in sedentary behavior resulted in a change in blood pressure, and 3) Establish the best recruitment sources for the target population, participant engagement and satisfaction with the intervention. METHODS: This study was a two-arm randomized controlled pilot feasibility trial comparing the change in objectively measured average daily percent sedentary behavior and blood pressure from baseline to post intervention between participants randomized to the Take a STAND 4 Health (TAS4H) intervention and an assessment only control. Independent and paired t-tests were used to determine whether there were significant changes between groups and within groups, respectively. In addition, multiple linear regression models were run to determine whether sedentary behavior was a significant predictor for change in blood pressure variables. RESULTS: Thirty-six individuals were randomized and 34 were retained for follow-up assessments. Participants were predominately white, well-educated females with a BMI of 35.4 + 6.4 kg/m2. No significant differences were observed for change in average daily percent sedentary time, systolic blood pressure or diastolic blood pressure between the treatment and control group. Multiple linear regression models failed to find evidence of an association between a change in sedentary behavior and mean change in systolic or diastolic blood pressure. When looking at recruitment, participant engagement and satisfaction with the intervention, most TAS4H participants previously participated in one of the lab’s interventions, were referred by a friend, or saw the intervention on a listserv. Engagement with the intervention was high and over 80% of participants feeling like the intervention was helpful for reducing sedentary time and agreeing that they would recommend the intervention to a friend. CONCLUSIONS: The TAS4H intervention was not effective in reducing sedentary behavior, which is likely why there was no relationship between sedentary time and blood pressure seen in this study. However, it was well liked and feedback from participants may help inform future sedentary behavior reduction interventions for this population.