Changes in human nasal resistance associated with exercise, hyperventilation and rebreathing.

The nasal resistance to airflow determined in four subjects for periods of up to 7 hr. Cyclic changes in the resistance of each nasal passage were demonstrated in 13 or 24 experiments. After exercise on the cycle ergometer the total nasal resistance decreased and this change in nasal resistance was found to be directly related to the work rate. After oral rebreathing, the total nasal resistance decreased, and after hyperventilation the total nasal resistance increased. These changes in resistance are believed to be caused by changes in arterial pCO2 and mediated by the autonomic innervation of the nasal vasculature.