 In congestive heart failure patients, inspiratory muscle weakness can be reversed by developing diaphragmatic hypertrophy through inspiratory muscle training, improving functional capacity and quality of life. In type 2 diabetes mellitus patients the frequency of inspiratory muscle weakness is unknown, as well as the response to inspiratory muscle training. For this reason, the present study evaluated the inspiratory muscle strength in type 2 diabetes mellitus patients and the effect of inspiratory muscle training on inspiratory muscle strength, pulmonary function, functional capacity and autonomic modulation assessed through heart rate variability. 