Inspiratory muscle training in stable COPD patients: enough is enough?

Inspiratory muscle dysfunction is a common finding in patients suffering from chronic obstructive pulmonary disease (COPD), contributing with other factors to dyspnoea and reduced exercise tolerance [1]. Pulmonary rehabilitation programmes (PRPs) including whole-body exercise training improve symptoms, exercise capacity and health-related quality of life (HRQL), and are recommended in all stages of COPD [2, 3]. In 1976, Leith and Bradley [4] were the first to show that the principles of training could be applied also to respiratory muscles: healthy strength trainers significantly increased their maximal static inspiratory and expiratory pressures. Endurance trainers increased their maximal voluntary ventilation but not maximal static pressures.