Patients with Chronic Obstructive Pulmonary Disease (COPD) and chronic respiratory insufficiency (CRI) have severe dyspnoea during exercise at low load. Physiological studies performed in these patients during a unique session of training have shown a positive effect on exercise tolerance if non-invasive mechanical ventilation (NIV) was added during incremental effort test or endurance. Menadue and coworkers (2009) have shown in CRI patients with hypercapnia, secondary to COPD or cifoscoliosis, that combination of NIV during arm effort test improved ability to perform the exercise. Similar result was not reached using NIV during walking. Further studies have underlined a positive effect of the ventilation therapy during exercise within specific programs of pulmonary rehabilitation (Corner 2009). Moreover, the addition of NIV to an exercise training (ET) program in COPD patients may produce greater benefits in exercise tolerance and quality of life than exercise training alone (Garrod 2000).