Non-invasive ventilation (NIV) is increasingly used in addition to exercise training in patients with chronic obstructive pulmonary disease with the purpose to allow them to train at higher intensities. Different modalities of assisted ventilation have been used with benefits for relief of dyspnoea and increase in exercise capacity. Nevertheless there are some potential problems with the use of NIV in pulmonary rehabilitation programmes. Despite promising results, a generalised use of NIV during exercise training programmes is unlikely to have a role in routine settings. The use of NIV during exercise training as a component of pulmonary rehabilitation should be reserved to individual cases.