This study will adapt a physical activity lifestyle intervention to emerging adult congenital heart disease (CHD) survivors with the primary goal of increasing physical activity levels.

The study will be split into 2 phases. In Phase 1, participants will be asked to complete questionnaires, wear an accelerometer around the waist for 7 days, and undergo an exercise stress test. The accelerometer and exercise stress test will be used to determine whether participants are eligible to be randomized for the intervention study. In Phase 2, participants will be randomized to one of two conditions: 1) receiving a physical activity tracker (a Fitbit) or 2) receiving a Fitbit AND engaging in videoconferencing sessions with a physical activity coach. During Phase 2, participants will also be asked to complete 3 assessments (weeks 9 and 22, and a 6-month follow-up). The week 9 assessment will consist of completing questionnaires and wearing an accelerometer for 7 days. Week 22 will be similar to week 9 with the addition of a final exercise stress test. The 6-month follow-up will mirror the week 9 assessment.

Participants who are randomized to the videoconferencing condition will be asked to meet with a physical activity coach 8 times over the course of 20 weeks. Coaches will help participants to (1) change attitudes toward physical activity, (2) increase perception of others' approval of physical activity (e.g., family members, peers), and (3) increase participants' perceived control by troubleshooting barriers and increasing efficacy for physical activity. Coaches will use the Fitbit to facilitate self-monitoring and goal setting. Participants in the intervention arm will be asked to participate in a focus group at the conclusion of the study to share their experiences.

Inclusion Criteria:

1. Between the ages of 18-25 (if 18, must no longer be in high school and no longer living at home)
2. Are diagnosed with moderate or complex structural congenital heart disease
3. Live within 120 miles of Nationwide Children's Hospital

Exclusion Criteria:

1. Do no speak or write proficiently in English
2. Have cognitive impairments that would interfere with the completion of study procedures
3. Are diagnosed with a genetic syndrome (e.g., Downs, Marfans)
4. Have been engaged in a formal exercise program within the past 6 months
5. Underwent open-heart surgery or have had a transcatheter valve replacement in the last 3 months
6. Are otherwise prohibited by their cardiologist to engage in at least moderate levels of physical activity
7. Are unable to complete a treadmill-based exercise stress test
8. Are currently pregnant
9. Have contraindications for exercise based on an exercise stress test (e.g., exercise-induced arrhythmias or evidence of cardiac ischemia)
10. >150 min/weekday of moderate-to-vigorous physical activity per the accelerometer
11. Do not have access or a device for videoconferencing with the coach

Three withdrawn participants (2 from Fitbit + Coaching Sessions arm and 1 from Fitbit Only arm) are excluded from the baseline analysis

Randomization to follow-up (approximately 22 weeks)

An adverse event is an unanticipated change in cardiovascular, musculoskeletal, or emotional symptoms that are (1) concerning to the participant and (2) results in seeking medical attention, if cardiovascular or musculoskeletal in nature. Any condition that is present at the time that the participant is screened will be considered as baseline and not reported as an adverse event.

Investigator, research assistants, coaches (interventionists), and participants do not know which condition a participant is in until the condition is revealed (opening an envelope with the condition listed) after the participant consents to Phase 2. Envelopes with the conditions were prepared by the study statistician.