Inspiratory muscle training: where are we?

Inspiratory muscle dysfunction has been shown to be related to hypercapnia and hence, to ventilatory insufficiency in patients with chronic obstructive pulmonary disease (COPD) [1]. Accordingly, treatment of inspiratory muscle dysfunction has gained interest in the last decade. Among other treatment modalities, such as pharmacotherapy and respiratory muscle rest, training of the inspiratory muscles is frequently applied in clinical practice, but its benefits largely remain a matter of debate [2]. Since LEITH and BRADLEY [3] showed increases in str-ength and endurance after training of inspiratory muscles in healthy subjects, there has been a substantial number of studies addressing the effects of inspiratory muscle training in various disorders, including: neuromuscular diseases, COPD, weaning failure, kyphoscoliosis and