The aim of this study is to demonstrate and quantify the micro architecture and micro vascular changes within skeletal muscles after marathon using 3T MRI (diffusion tensor and arterial spin labeling). Apparent diffusion coefficient, fractional anisotropy and flow parameters will be registered before and after the long-distance run on the lower leg. Axial T1 and axial SPAIR sequences will also be applied at the same time.Stress ox and inflammatory markers will be collected in blood and urine samples and compare with both MRI and Near-infrared spectroscopy (NIRS).

Inclusion Criteria:

• Realizing between 2:10 and 4:30 in the marathon.

Exclusion Criteria:

• Smoker
• Subject with medical treatment or with a treatment interrupted for less than 30 days.
• Subject with a osteo-articular, cardiovascular, infectious, lung pathology and/or a metabolic chronic pathology.
• MRI Contraindication : Claustrophobic subject ; subject with a intra-cranial vascular clip, with a pacemaker, with a neurostimulator or a cochlear implant ; subject with intraocular metallic foreign bodies.