Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com 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 IMT programs require regular supervision but are rel- atively 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 discontin- ued [6]. Whether training conducted with appropriate load also translates into increased exercise tolerance and better quality of life is still unclear, thus making the evi- dence-based guidelines [7, 8] to conclude that IMT should not be a routine component in the rehabilitation pro- grams. In this issue of Respiration , Weiner et al. [9] pointed out a practical problem in the management of COPD patients showing weakness of their inspiratory muscles. This may cause, in turn, the inability to generate ade- quate flow to assure lung deposition when using dry powder inhalers (DPIs), which are commonly pre- scribed to deliver bronchodilators to these patients. Bioavailability is predictive of the clinical effect of the inhaled drug [10] and peak inspiratory flow (PIF) mea- surements reflect the patient’s ability to properly inhale the drug. Authors have found that almost 20% of the most com- promised patients (staged according to the forced expira- tory volume in 1 s) are not able to generate enough flow to assure proper inhalation (and therefore deposition) from one of the most popular and commonly used de- vices (Turbohaler) and that, in addition, PIF values cor- Inspiratory muscles have been specifically targeted for training patients with chronic obstructive pulmonary dis- ease (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 disad- vantage due to hyperinflation, respiratory muscles are likely to adapt to the chronically imposed work of breath- ing [1], and the diaphragmatic contractile fatigue is rare- ly observed even during strenuous exercise in stable dis- ease [2]. On the one hand, respiratory muscles, unlike the peripheral muscles, apparently do not to suffer from de- conditioning, 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 adapta- tion may be insufficient. Therefore, if inspiratory muscle training (IMT) is able to increase the maximal inspiratory muscle pressure (PI max ), and to change the structure of these muscles, it seems reasonable to expect that symptoms will be re- duced while exercising, thus turning these effects into a functional benefit. These positive effects have been con- firmed in COPD patients with inspiratory muscle weak- ness by a recent systematic review [5]. Dr. Enrico Clini Fondazione Villa Pineta Division of Pneumology and Pulmonary Rehabilitation, Via per Gaiato 127 IT–41020 Pavullo (Italy) Tel./Fax +39 0536 42039, E-Mail eclini@qubisoft.it © 2006 S. Karger AG, Basel 0025–7931/06/0732–0143$23.50/0 Accessible online at: www.karger.com/res