Hyperpnea training

Each hyperpnea session was 20-minutes in duration with the target ventilation (V˙E) set as follows: days 1–4, 70% MVV; days 5–7, 75% MVV; days 8–10, 80% MVV. For each subject, the MVV obtained on the first training day was used to assign target V˙E throughout the ten days of training. Subjects were instructed to select their own breathing pattern during the hyperpnea sessions. Thus, subjects’ only goal was to do their best to reach and maintain the target V˙E; they were not provided any instructions regarding VT or fb. During each hyperpnea training session, subjects were seated comfortably in a chair with a computer monitor placed at eye-level. Real-time V˙E was displayed on the monitor and subjects voluntarily titrated their breathing to match the target as closely as possible.