[From walk test to cardiopulmonary exercise test]

Cardiopulmonary exercise test is a new respiratory functional test used for sick children. It demonstrates the integrated response of all the systems involved in exercise (especially cardiac and respiratory ones) and consequently evaluates exercise adaptations during chronic disease. This dynamic test assesses exercise tolerance, and so quality of life more objectively than a resting test. Values measured (especially oxygen uptake and ventilatory threshold) are quantifiable and reproducible, allowing the follow-up of a disease and the initiation and individualization of exercise training. Moreover, it is also useful for diagnosis and assessment of abnormal symptoms during exercise (as dyspnea), especially abnormalities that are undetectable during rest. The six-minute walk test, the step test and the shuttle test are rapid, simple and low-cost field tests that give adequate information on the daily physical performance (walking, climbing stairs, or running) of the sick child. They allow a closed follow-up, especially during an exercise training period. However, only the cardio-pulmonary exercise test can allow the physical practise in sick children, eliminating the contra-indications.