Cancer

Editorial
Respiration 2006;73:143–144 DOI: 10.1159/000091529

Inspiratory Muscle Training: A Way to Breathe More Easily
Enrico Clini Stefania Costi
Department of Pulmonary Rehabilitation, Fondazione Villa Pineta and University of Modena, Pavullo, Italy

Inspiratory muscles have been specifically targeted for training patients with chronic obstructive pulmonary disease (COPD). So far, the rationale for training has been questioned. Although inspiratory muscle strength is low in most of these patients, mainly because of the mechanical disadvantage due to hyperinflation, respiratory muscles are likely to adapt to the chronically imposed work of breathing [1], and the diaphragmatic contractile fatigue is rarely observed even during strenuous exercise in stable disease [2]. On the one hand, respiratory muscles, unlike the peripheral muscles, apparently do not to suffer from deconditioning, and a training intervention does not appear justified on this basis. On the other hand, the work of the diaphragm is clearly increased during exercise [3], thus leading to perception of ‘difficult inspiration’, ‘shallow breathing’ or ‘unrewarded inspiration’ [4], especially in some COPD patients whose respiratory muscle adaptation may be insufficient. Therefore, if inspiratory muscle training (IMT) is able to increase the maximal inspiratory muscle pressure (PImax), and to change the structure of these muscles, it seems reasonable to expect that symptoms will be reduced while exercising, thus turning these effects into a functional benefit. These positive effects have been confirmed in COPD patients with inspiratory muscle weakness by a recent systematic review [5].

IMT programs require regular supervision but are relatively inexpensive and can be conducted at home. One study investigating the long-term effect of IMT suggested that benefits wear off rapidly when training is discontinued [6]. Whether training conducted with appropriate load also translates into increased exercise