Remote Cardiac Rehab for Adolescents With Congenital Heart Disease

Inclusion Criteria: 1. Age 12-19 years old 2. Male or Female 3. Diagnosed with one of three congenital heart diseases: Univentricular heart with Fontan Palliation Tetralogy of Fallot with transannular patch Dextro-transposition of the great arteries with arterial switch operation 4. Primary Cardiology clearance for exercise participation 5. Internet access in their homes 6. Available for in-home exercise between 4-7pm on at least 3 days of the Monday-Friday work week 7. English Speaking 8. Achieving maximal effort on a cardiopulmonary exercise test, defined as RER ≥1.1 and/or in the judgement of the supervising exercise physiologist, a maximal effort was achieved but exercise capacity is limited by musculoskeletal deconditioning. Exclusion Criteria: 1. Physically or developmentally unable to perform outcomes assessments or participate in moderate-to-vigorous intensity physical activity 2. Participating in \> 15 MET-hours per week (mean weekly average over the past 12-months) of organized athletic/exercise activity (not including school physical education class). 3. Height less than 132cm 4. Pregnancy or planned surgery or procedure (excluding outpatient, non-cardiac procedures) within the 12-week study period. 5. Meeting at least 1 exercise test safety or screening criteria on most recent exercise test (pre-study) or baseline outcomes visit exercise test 6. Presence of significant cardiac dysfunction that would impair safe participation in moderate-to-vigorous intensity exercise 7. Significant changes baseline echocardiogram or most recent clinical echocardiogram (from past clinical echocardiogram) such as decrease in ventricular and/or valvar function, new obstruction, or any new structural abnormalities 8. Uncontrolled or poorly controlled asthma 9. Presence of implanted cardioverter-defibrillator 10. Pacemaker with rate-responsive function initiated 11. Reliance on ventricular assist device 12. Prescribed milrinone medication 13. Listed for heart transplantation 14. Active engagement in hormone replacement for gender transition