Behavioral Exposure for Interoceptive Tolerance (BE-FIT) is a mechanism-informed behavioral intervention to target exercise anxiety. The three primary components of BE-FIT include: (1) exposure to feared bodily sensations and exercise; (2) prevention of safety behavior use before/during/after exercise, and (3) use of a wrist-worn activity monitor for physical activity (PA) feedback and activity goal setting. Evidence from the investigators' Stage I trial indicated that BE-FIT is feasible, acceptable, and safe and produced reductions in exercise anxiety and increased exercise outcomes (short-term moderate-to-vigorous intensity physical activity and steps/day). The investigators' present aim is to conduct a Stage II randomized-controlled trial to further evaluate the efficacy of BE-FIT in decreasing exercise anxiety in cardiac rehabilitation (CR) patients and examine whether changes in this target yield successive changes in exercise adherence outcomes.

This study is a Stage II randomized-controlled trial of a novel behavioral intervention, titled Behavioral Exposure for Interoceptive Tolerance (BE-FIT), to evaluate (1) its efficacy in improving exercise adherence in CR and (2) its mechanisms of change in individuals 40 years of age and older. One hundred and forty-six patients enrolled in Robert Wood Johnson University Hospital (RWJ) cardiac rehabilitation (CR) program who have elevated exercise anxiety, as indicated by endorsement of much to very much concern about at least 3 items on the Exercise Sensitivity Questionnaire (ESQ; Farris et al., 2020) and meet other eligibility criteria will be randomly assigned to either receive BE-FIT, a tailored intervention specifically for CR patients with high levels of exercise anxiety (n=73), or the health education condition (HEC; n=73), which are matched for contact time. Eligible participants will be stratified based on their risk profile (determined by their electronic health record), age, sex, and ESQ score. These stratification variables were selected because they are associated with anxiety and fitness levels which could impact physical activity (PA) outcomes. Both conditions will be administered by trained doctoral-level students enrolled at Rutgers University and will be supervised throughout the course of the study by Dr. Farris and other listed co-investigators.

The BE-FIT intervention is a cognitive-behavioral intervention and is designed to target exercise anxiety. The three main components of BE-FIT include: 1) exposure to feared bodily sensations and exercise, 2) prevention of safety behavior use before/during/after exercise, and 3) use of a wrist-worn activity monitor (Fitbit) for PA feedback and activity goal setting. The alternative type of intervention is the Health Education Control (HEC), which is a time-matched control intervention that will be delivered on the same delivery schedule as BE-FIT. The doctoral-level clinicians who will be delivering HEC will be exclusively trained in order to avoid contamination with the BE-FIT intervention. In this control arm, participants will be provided educational information about health topics relevant to healthy aging delivered through PowerPoint lectures and handouts and use a Fitbit for PA monitoring. The HEC protocol has been used in prior studies conducted by Dr. Abrantes (co-investigator).

The overall duration of the study is 24 weeks, or approximately 6 months. Subjects will be involved in 6 individual sessions delivered twice weekly during the initial weeks of outpatient CR. Sessions occur for 45 minutes either immediately before or after regularly scheduled CR sessions. Five independent assessments are conducted at baseline, EOT, and three follow-ups (Weeks 12, 18, 24). Data collection will occur at each visit, with baseline data collected at the initial visit.

Inclusion Criteria:

1. ≥ 40 years of age
2. Elevated exercise anxiety (score of ≥ 30 on ESQ-18)
3. Low active (< 90 min self-reported moderate-to-vigorous intensity physical activity/day in past three months)
4. Medically approved cardiac rehabilitation
5. English proficiency

Exclusion Criteria:

1. Evidence of cognitive impairment (≤ 23 on Montreal Cognitive Assessment; MoCA)
2. Severe disabling chronic medical and/or psychiatric comorbidities determined on a case-by-case basis that prevents safe or adequate participation
3. Expectation that patient will not live through study periods