Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease with related exercise intolerance and marked disability due to symptoms such as dyspnea and fatigue. Effort intolerance and exercise-induced symptoms cause marked impairment in completing activities of daily living (ADL). Pulmonary rehabilitation (PR), which has exercise as a major component, is considered a key treatment in the management of COPD since PR is effective in improving exercise tolerance, exercise-induced dyspnea and fatigue, and health-related quality of life. Rehabilitation is also effective in improving the time required to perform ADLs, reducing symptoms and disability. Studies show that rehabilitation protocols with upper limb exercises added to lower limb training are able to give additional benefits in terms of effort tolerance (endurance time at the arm ergometer and oxygen consumption) and reduction of dyspnea at iso-load. The primary aim of this study is to evaluate whether the combined arm and leg training modality, compared to a gold standard protocol -involving only the lower limbs training- is more effective in improving ADL performance in terms of reduction of exercise time for a specific test (GLITTRE test).