This study leaves us with some speculative problems. Indeed, on the basis of this small study, we do not know whether reduced respiratory muscle endurance is the cause or the consequence of prolonged mechanical ventilation. Furthermore, the suggestion of utility of IMT is purely speculative and rather questionable. The rationale for using IMT in the ICU is controversial. Respiratory muscle function per se is not the only factor involved in a delay in weaning. As a matter of fact, respiratory pump efficiency is a result of the balance between the load that the respiratory system has to face and its capacity. In patients with some diseases, such as COPD, ARDS, interstitial lung disease, and chronic heart failure, the elastic and resistive loads are elevated as much as three to four times compared to levels in healthy individuals.8 In these populations, particularly in COPD patients, IMT was suggested as a possible intervention strategy for increasing the inotropic or endurance properties of the diaphragm.