Behavioral Exposure for Interoceptive Tolerance (BE-FIT): A stage II randomized clinical trial protocol

BACKGROUND: Exercise anxiety is a novel mechanism related to non-adherence to exercise and lifestyle physical activity. We developed a cognitive-behavioral treatment, Behavioral Exposure For Interoceptive Tolerance (BE-FIT), which is a manualized, values-based exposure intervention designed to target exercise anxiety that is delivered as a supplement to outpatient cardiac rehabilitation (CR). METHOD: We describe a Stage II randomized controlled trial (RCT) to test BE-FIT, compared to a Health Education Control (HEC) intervention on exercise and physical activity outcomes at end-of-treatment (EOT) and follow-ups (Weeks 12, 18, and 24), and evaluate mechanisms of change (i.e., reductions in exercise anxiety). Adults (N = 146) who are ≥40 years of age, cleared for outpatient exercise-based CR, low active, and have elevated exercise anxiety will be recruited. The primary study hypothesis is that BE-FIT compared to HEC will result in higher levels of overall exercise and lifestyle physical activity at EOT and follow-ups. The second hypothesis is that BE-FIT vs HEC will produce greater reductions in exercise anxiety at EOT and Week 12. The third hypothesis is that reductions in exercise anxiety at EOT and Weeks 12 will mediate the effect of BE-FIT on activity outcomes at Weeks 18 and 24. DISCUSSION: We expect the results of this study will produce knowledge regarding BE-FIT's efficacy and mechanisms of action. Our goal is to better understand "how and why" the intervention is (or is not) effective and for whom, and increase collective knowledge and reproducibility of behavior change research.