Neuromuscular diseases (NMD) are characterized by a reduced maximum insufflation capacity (MIC), which contributes to increased morbidity and mortality from respiratory diseases. Techniques such as glossopharyngeal breathing (GPB) and insufflation using a manual resuscitation bag, or "air stacking (AS)", can be used to increase the MIC. These techniques employ different mechanisms, and the ability to learn the technique plays a key role in its proper implementation and effectiveness. The objective is compare the effects of AS and GPB on the MIC in patients with NMD.