Only a few research had looked at the effect of physical activity on exercise capacity and health-related quality of life. For a study, researchers sought to analyse the Cardiopulmonary exercise tests (CPET) in a broad group of patients with Fontan circulation. Questionnaires were utilised to evaluate health-related quality of life as well as physical activity. At CPET, 79 patients with a median age of 13.0 (6.5 to 34.4) years (female, n=31) were enrolled. According to questionnaires, 80% of patients (n=63) participate in leisure activities, with 43% (n=27) exercising for more than 2 hours each week. Investigators discovered that nearly all juvenile patients (n=52) participate in school sports (n=51) and had good subjective health (n=48) in a subgroup analysis. In the paediatric subgroup, anaerobic threshold oxygen uptake and peak oxygen uptake were associated to subjective health (p<0.05) and leisure sports activity (p<0.01). Running duration and distance were significantly linked with the number of hours of sports per week in the total cohort (p<0.01). The outcomes of the CPET test did not differ significantly between patients with a single right and single left ventricle. Additionally, an open fenestration was not linked to a reduction in exercise ability. Finally, most individuals with a Fontan circulation engage in recreational activities and report high subjective health. Increased sports participation in children was linked to improved exercise capacity and subjective health.