Reduced exercise tolerance is one of the hallmarks of COPD and The principal causes for exercise intolerance are ventilatory limitation leading to deconditioning and inactivity. However the weak correlation between exercise capacity and FEV1 implies that other factors than reduced pulmonary function contributes to this impairment . Several studies have found changes in skeletal muscle, with fibre shift, increased oxidative stress, increased inflammatory cytokines and impaired mitochondrial function, suggesting a lower limb dysfunction