All over the world 0.8 % of all live children are born with a Congenital Heart Disease (CHD) due to genetic end environmental causes. Advanced treatment and care has enhanced survival substantially, and adults with CHD are a growing population requiring continuous monitoring and care. Presently 25% of young adults acquire complicating Cardio Vascular Diseases (CVD) in young adulthood amongst other co-morbidities.

It is known that adolescents with CHD are not as physical fit (PF) as their cardiac capability allows, most likely for reasons concerning safety, ability plus inactive everyday life. However, in 2006 The European Society of Cardiology states, that regular exercise at recommended levels can be performed and should be encouraged in all patients with CHD. Training programmes in hospitals have an effect on PF and Quality of Life (QoL) for the few, as most adolescents' find it impossible to fit into everyday life.

It is the investigators hypothesis that an eHealth intervention, to facilitate intensive exercise in the patients' neighbourhood environs, may improve physical fitness more efficiently than standard lifestyle education.

The purpose of the study is to create evidence to recommend an efficient, fun and safe cardiac rehabilitation programme to adolescents with CHD.

Primary outcome measure

Cardiopulmonary exercise capacity: Online V02 max bicycle test

Secondary outcome measure

Level of physical exercise: Actigraph and Questionnaire

Tertiary outcome measure

Quality of Life: PedsQl

Prevail is a national prospective, randomized clinical trial including 216 adolescents aged 13-16 years, who have had cardiac surgery in childhood owing to complex CHD. The patients included are all recommended to be as physical active as their healthy peers and pursue the principle guideline from The National Board of Health: "All children and young people must be physically active for at least 60 minutes a day, preferably longer". Patients with mental retardation and FEV1 at baseline < 80% of predicted are excluded.

The risk of participating in the purposed trial is not regarded as higher than everyday daily living.

Results will be interpreted according to affiliation to health related fitness clusters.

Inclusion Criteria:

• Congenital heart disease with allowance for unrestricted exercise
• Diagnosis: Q20.0 Truncus arteriosus communis, Q20.1 Transpositio vasorum incompleta, Q20.3 Transpositio vasorum completa, Q20.5 Inversio ventriculorum cordis, Q21.2 Defectus septi atrioventriculorum cordis, Q21.3 Tetralogia Steno-Fallot, Q22.4 Tricusspidalatresia , Q22.5 Anomalia Ebstein, Q23.2 Mitralatresia, Double outlet right ventricle, Q23.3 Hypoplasia ventriculi sinistri cordis syndrome, Q23.3 Hypoplasia ventriculi dextrii cordis syndrome, Q24.4 Stenosis subaortae congenita, Q25.1 Coarctatio aortae, Q25.1 Coarctatio Aortae, Double inlet left ventricle, Q25.3 Stenosis aortae supravalvularis, Q25.5 Pulmonalatresia.
• Successful Total Cavo Pulmonal Connex (TCPC procedure)
• 13- 16 years of age

Exclusion Criteria:

• Mental retardation
• Untreated asthma
• Syndromes related to CHD