Exercise and nasal patency

Abstract
Nasal airflow resistances were studied in 20 healthy subjects at rest, with exercise, and during recovery from exercise. Resistances were first measured under resting conditions. As a basis for comparison 0.1% xylometazoline was applied by insufflation; it reduced nasal resistance by an average of 49%. On a subsequent occasion, the degree and time course of changes in resistance were measured 1) during 5-min exercise bouts at rest 25, 50, and 75% of predicted maximum O2 intake (VO2max), 2) during 5-, 10-, and 15-min exercise bouts at 50% of VO2max, and 3) during recovery from exercise. Resistance decreased with intensity but not duration of exercise; an initial sudden decrease was followed by a more gradual but progressive decrease, which continued for several minutes following vigorous short duration exercise. Thus following 5 min of effort at 75% of VO2max, resistance reached a nadir (46% fall) 5 min after cessation of exercise. Recovery of preexercise values required 5 min after 5 min of exercise at 25% of VO2max and 10 min after 5 min of exercise at 50% of VO2max. Some decrease persisted 15 min after 5 min of exercise at 75% of VO2max.