Abstract: In accordance with the present invention, a breathing exercise training apparatus is provided for increasing the endurance of inspiratory muscles. This is accomplished by setting a target breathing frequency, target inhalation time and target inhalation pressure on a target generator, and then having the trainee breathe into a resistive breathing device that imposes a predetermined resistance to inhalation and communicates actual inhalation pressure to the target generator. The target generator includes structure for comparing the actual inhalation time and pressure with the target values and provides a feedback signal in response thereto. A preset time interval is provided within which the trainee must attain the target inhalation pressure after an inhalation cycle begins, or a "fault" signal is given to the trainee. Thus, the apparatus of the invention forces the trainee to exercise his inspiratory muscles in order to achieve the target inhalation pressure within the target time.