A pressurized flow of breathable gas is delivered to the airway of a subject in accordance with a therapy regimen. The therapy regimen calls for maintenance of an average tidal volume. The therapy ensures that the subject breaths at a therapeutic breath rate. The breath rate may be determined dynamically based on breathing of the subject early on in a therapy session and/or based on a detected wakefulness of the subject. Inspiration for spontaneous and non-spontaneous breaths may be supported at different levels. The therapy regimen further maintains a beneficial positive end expiratory pressure, to reduce respiratory obstructions and/or for other purposes.