Changes in gastric twitch pressure (P
) during thoracic magnetic stimulation immediately after and 30 min after the 15-min hyperpnoea test in normoxia (diamond), hypoxia (triangle) and hyperoxia (square). Values are mean ± SD. All values were significantly reduced immediately after and 30 min after hyperpnoea compared to before hyperpnoea. * significantly different from normoxia and hyperoxia (P < 0.05).