The importance of nose-breathing for the systolic blood pressure rise during exercise.

The effect of nose breathing on the systolic blood pressure was examined in ten healthy men. Nose breathing was increased above normal by exercise and tested by maximum bicycle ergometry. When the anterior part of the nose was dilated with Nozovent the nasal airflow increased by on average 29%. In this condition, all ten men could cycle at maximum load without mouth breathing and there was a significantly lower increase (13 mmHg) in the systolic blood pressure than when the nasal dilator was not used. The reason for this lower blood pressure increase is unknown. The hypothesis is put forward, however, that facilitated nose breathing decreases the respiratory work, which in turn lowers the systolic blood pressure during exercise.