The measurement of the transcutaneous oxygen pressure during walking allows to estimate the importance of ischemia, bilaterally and segment of limb by segment of limb. The determination of the metabolic compounds concentration, with metabolomic approach, is emerging in physiology and exercise.

This pilot study focuses on the feasibility of the metabolomics analysis with micro method , by capillary drawing from earlobe sampling, for patients with peripheral artery disease (PAD)

Ankle brachial index is measured at rest for alml subjects. Blood sample (180-360 microliter) will be collected at rest transcutaneous oxygen pressure is measured at the chest, calves and buttocks and results will be expressed as the minimal value of the DROP index (Limb changes minus chest changes) Patients walk on treadmill (2MPH 10% slope) until exertional limb pain. Blood sample (180 microliter) will be collected again, at minute 3 of recovery from walking Correlation of each metobolite increase to the sum of DROP values wil be studied.

Inclusion Criteria:

• Age > 18 years old
• Patient able to walk on a treadmill
• Patient agrees to be involve in the protocol and sign the consent form

Exclusion Criteria:

• Patient not covered by the French health insurance
• Patient has a wash-out period for another clinical trial
• Patient with comorbidity as bleeding disorder or with a anticoagulant therapy

Metabolomic analysis will be performed blinded to the exercise test results