The 6-minute walking test is currently the gold standard for the evaluation of oxygen desaturation phenomenon during exercise and for the adjustment of O2 flow rate. But, due to spatial constraints, this test remains difficult to apply in ecological conditions and the 3-minute step test could be a complementary method to the walking test for the evaluation of chronic respiratory diseases. For this study, patients will perform, during 2 visits, a maximal graded test and two field tests (6-min walking test and 3-min step test) under identical conditions. During these tests, pulsed oxygen saturation and psycho-physiological adaptations to exercise will be monitored.
