Inclusion criteria for CCS group :  aged between 5 and 25 years old, having been complete a full regimen for oncological disease and considered in remission at the end of treatment. Remission was considered in absence of relapse or new treatment initiated before the CPET end point.  Inclusion criteria for control group :  children referred for a nonsevere functional symptom linked to exercise (murmur, palpitation or dyspnoea) or for a medical sports certificate. completely normal check-up, including physical examination, ECG, echocardiography and spirometry.  Exclusion criteria for control group:  Children with any chronic disease, medical condition (cardiac, neurological, respiratory, muscular or renal) Children with any medical treatment Children requiring any further specialised medical consultation