 COPD will constitute the third cause of mortality in 2012. This chronic respiratory disease is characterized by peripheral dysfunction of skeletal muscle which is associated with major clinical outcomes prognostics, symptoms, and health related quality of life. Muscle and systemic oxidative stress has been incriminated in this peripheral muscle dysfunction.Exercise training constitute the main validated therapeutic intervention leading to significant muscle function and clinical improvement.Our preliminary results have shown that COPD patients experiment dietary and enzymatic antioxidants defects.Yet, generic antioxidant supplementation has not shown significant muscle function improvement.Therefore, we aim to test the effects of an antioxidant supplementation targeted on the antioxidant defects associated with exercise training on the peripheral muscle function, exercise tolerance and health quality of life in COPD patients.At the cellular level, this muscle dysfunction is related with a fiber atrophy and a metabolic switch reduce proportion of oxidative fiber.This study will compare the effects of an antioxidant supplementation on the peripheral muscle function and skeletal muscle cellular properties in association with exercise training during a pulmonary rehabilitation course.Volunteers will be randomised in 2 groups: - 1 group treated with the antioxidant supplementation 28 days- 1 group treated with the placeboIntervention will be allocated by chance and a double blind manner. Antioxidant supplementation will associate vitamins and trace elements that wont exceed the maximal nutritional dose recommended. 