Moderate levels of activity may be tolerated, but careful exercise testing is important before setting limits. Isometric exercises, such as weightlifting and downhill skiing, should be avoided, as well as extreme exertion and dehydration.

The effects of the Fontan operation on the performance of the lungs and on the anatomy of the thorax may also be factors in determining safe levels of exercise. If a patient has been prescribed the anticoagulant warfarin, contact sports should be avoided as they may lead to serious injury.

Anyone with congenital heart disease, repaired or non-repaired, should consult with their cardiologist about physical activity to review the risks.