The goal of this observational study is to learn about how a prescribed Exercise Training Program would affect children living with a Fontan circulation.

From birth, the children who are born with single functioning ventricle will undergo 3-staged Fontan surgery to achieve a unique Fontan circulation, supported by one functioning ventricle. With advancement in surgical technique and medical care, there are increasing number of children living with Fontan circulating surviving into adulthood.

A significant number of these individuals develop complications in their adulthood due to problems related to this unique circulation, including reduced exercise tolerance, heart failure, abnormal heart rhythm or premature death. Many of these children have acquired sedentary lifestyle, and may have lower self-perceived health related quality of life.

Exercise training is a well-established therapy used in adult population with heart failure. It has been shown to be safe in children with congenital heart disease and with Fontan circulation, it improves their aerobic exercise capacity which is associated with better outcomes.

The main question[s] it aims to answer are the impact of a Exercise Training program on:

1. Single ventricle function
2. Exercise capacity
3. Self-perceived quality of life
4. Skeletal muscle mass

Participants will be given a 20-weeks exercise program, 3 sessions of 30 minutes workout weekly, to carry out at home. The following tests will be performed prior to starting and upon completion of the exercise program:

• Echocardiogram
• Cardiopulmonary exercise test
• Body composition scan using a bio-impedance analyser
• Quality of life questionnaires

Inclusion Criteria:

• Patients with Fontan circulation, age range 8 to 18 years
• Ability to perform a cardiopulmonary exercise stress test (CPET)
• Free from acute or chronic respiratory illness and/or conditions that might affect exercise performance
• Who have had a Fontan operation at least six months prior.

Exclusion Criteria:

• Existing neuro-disability i.e. with paresis post cerebrovascular accident
• Neurodevelopmental issue with inability to comply with commands.
• Documented life-threatening arrhythmia without implantable cardioverter defibrillator
• Moderate or severe atrio-ventricular valve regurgitation
• Moderate or severe ventricular dysfunction by echocardiography exams
• Acute inflammatory cardiac disease
• documented coronary artery stenosis and/or myocardial ischaemia
• Heart failure requiring hospitalisation in the past year
• Evidence of systemic venous pathway obstruction by echocardiography or catheterisation
• Resting oxygen saturation < 90%
• Systemic ventricular outflow tract stenosis with peak resting systolic gradient > 50mmHg

Children aged 8 to 18 years old, who are living with a Fontan circulation, who have met the eligibility criteria listed above.