for the members of the Southwest Congenital Cardiac Consortium Feature Editor's Note-The Fontan operation, in many respects, is the signature operation for congenital heart surgeons. At our Heart Center, palliative operations leading up to the Fontan procedure, the Fontan procedure itself, and post-Fontan surgical interventions account for 20% of our congenital cardiac surgery case volume. Over the past 45 years, the Fontan operation has evolved steadily with numerous technical modifications as surgeons have sought to improve patient outcomes. The resources and attention devoted by heart centers to the totality of care of Fontan patients is enormous. In a recent issue of The Journal of the American College of Cardiology, Atz and colleagues from the Pediatric Heart Network Investigators reported on nearly 500 patients undergoing a thorough health assessment 9 years after their previous landmark Fontan crosssectional study. The authors noted a concerning finding in these patients: Exercise performance decreased over the years and this was associated with worse functional health status. We are fortunate to present an invited expert opinion summarizing and augmenting this article by Yves d'Udekem. d'Udekem is a passionate advocate for Fontan patients. He is the founder and chair of the Australian and New Zealand Fontan Registry. He estimates that there are currently 70,000 patients with a Fontan circulation. d'Udekem has reviewed the findings of Atz and colleagues and added to this his own extensive experience with the very robust Australian and New Zealand Fontan Registry. That comprehensive database goes back 35 years, and they have found that a high level of physical activity and exercise training optimizes outcomes after the Fontan procedure. This analysis will further advance steps we can take to improve the lives of this complex cohort of patients.