Effects of exercise on nasal airflow resistance in healthy subjects and in patients with asthma and rhinitis.

We studied the effect of exercise on nasal airflow resistance (Rnaw) and the relationship between exercise-induced asthma (EIA) and Rnaw. Rnaw was obtained by measurement of flow through the nose and mouth (in series) at constant inflow pressure. In seven healthy subjects, there were statistically significant decreases in Rnaw (39.5 +/- 6.3 and 49.0 +/- 8.2%; p less than 0.05) and no change in forced expired volume immediately after exercise on a bicycle ergometer at both 75 W and 100 W, but there was no significant difference between these two resistance changes. At 75 W, Rnaw returned to pre-exercise level at 15-20 min after exercise. At 100 W, Rnaw remained below the pretest value 30 min after exercise. In eleven asthmatics, treadmill running for 1, 2 and 6 min caused significant decreases (p less than 0.05) in Rnaw up to 44.8 +/- 3.3%, reaching levels similar to those of controls after exercise. With 6 min exercise, four of nine patients developed EIA; these subjects had allergic rhinitis as well, and recovery to pretest valued tended to be quicker than in those without EIA. In healthy subjects at both ergometer workloads, there was a rebound increase in Rnaw in 40-50% of the subjects appearing 20-30 min after exercise. In the patients, there was a rebound increase in Rnaw in about 60% of the subjects 5-10 min after exercise. Both for healthy subjects and patients, the rebound increase in Rnaw was smaller at the higher workloads.