We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.

In spite of similar measured total activity, Fontan patients reported less time engaged in regular physical exercise than healthy controls and their quality of life was lower than the controls. We speculate that promoting structured regular physical exercise could improve the quality of life of Fontan patients.

Fontan patients have a restrictive lung pattern, reduced pulmonary diffusing capacity, and reduced maximal oxygen uptake compared with healthy controls. Endurance training may improve vital capacity in Fontan patients. The normal increase in pulmonary diffusing capacity with age and growth was reduced in Fontan patients, which is concerning. Apart from general health effects, exercise may improve lung function in young Fontan patients and should be encouraged.

Objective:To study physical activity and sleep in Fontan patients and healthy controls before and after an endurance training program, and after 1 year.Method:Fontan patients (n = 30) and healthy controls (n = 25) wore accelerometers for seven consecutive days and nights during a school week before and after a 12-week endurance training program and after 1 year.Results:Patients had similar sleep duration and sleep efficiency as healthy controls. Latency to sleep onset in minutes was longer for patients than controls (22.4 (4.3–55.3) minutes versus 14.8 (8.6–29.4) minutes, p < 0.01). More time in moderate-to-vigorous activity daytime was correlated with increased sleep time (p < 0.05; r2 = 0.20), improved sleep efficiency (p < 0.01; r2 = 0.24) and less time as wake after sleep onset (p < 0.05; r2 = 0.21) for patients but not controls. Sleep variables did not change after the exercise intervention for patients or controls. After 1 year, patients had decreased total sleep time, decreased sleep efficiency, increased accelerometer counts during sleep and more time as wake after sleep onset during sleep time, but not controls.Conclusions:Fontan patients have prolonged latency to sleep onset compared with controls. More time in physical activities was correlated with better sleep quality for the patients. Also, subjects with low sleep efficiency and long latency to sleep onset may benefit most from physical exercise. These patients should be encouraged to engage in individually designed physical exercise as this could improve sleep quality.

Abstract Introduction: Impaired isometric muscle strength was previously reported in adults with Fontan circulation. However, it is unclear if this impairment is present in children and adolescents with Fontan circulation. We investigated isometric muscle strength of the lower limb in patients (6–18 years) with Fontan circulation in comparison with healthy controls. Method: In this cross-sectional study, 43 patients (6–18 years) with Fontan circulation and 43 age- and sex-matched controls were included. Isometric knee extension and plantar flexion muscle strength were assessed using dynamometry (Newton, N). Lean mass of the legs was assessed with dual-energy X-ray absorptiometry. Analyses were performed on group level (n = 43), and for subgroups that included children aged 6–12 years (n = 18) and adolescents aged 13–18 years (n = 25). Results: On group level, the patients with Fontan circulation had impaired isometric knee extension strength in comparison with the controls (p = 0.03). In subgroup analyses, impaired isometric knee extension strength was present in the adolescents (p = 0.009) but not in the children groups. For plantar flexion, there was no difference between patients and controls. There was no difference in lean mass between patients and controls (9.6 ± 4.3 kg vs. 10.8 ± 5.6 kg, p = 0.31). However, the lean mass was highly correlated to isometric knee extension strength (patients r = 0.89, controls r = 0.96, p < 0.001) and isometric plantar flexion strength (patients r = 0.7, controls r = 0.81, p < 0.001). Conclusion: The finding of impaired isometric knee extension muscle strength in adolescents (13–18 years) with Fontan circulation and no corresponding impairment in the children group (6–12 years) could imply that isometric muscle strength gets more impaired with age.