A blood sample will be drawn just before the start of the test, that is 5 minutes after the end of the last cuff deflation. A second blood sample will be drawn 2 minutes after the patient's request to stop walking. These blood samples are composed of one 3ml tube to measure out blood lactate level, one 6ml ethylene diamine tetraacetic acid (EDTA) tube and a 5ml plain tube. These two last tubes will be centrifuged and subsampled to build up a bio-collection stored at the local Biological Resources Center.