Evaluation of nasal volume by acoustic rhinometry before and after physical exercise

Background: The nasal structures generate airflow resistance that can reach similar to 50% of the total respiratory resistance. There are a series of factors that can alter the volume of these structures, among them physical exercise. The objective of this study was to determine the degree of changes in nasal volume at different levels of physical exercise, evaluating the influence of exercise intensity and duration, as well as the duration of the effect of exercise on the nasal mucosa. Methods: Nineteen individuals were submitted to three distinct physical tests on a cycle ergometer: test 1, exercising for 5 minutes on a cycle ergometer at 50% the maximal load; test 2, exercising for 10 minutes on a cycle ergometer at 50% the maximal load; and test 3, exercising for 5 minutes on a cycle ergometer at 75% the maximal load. In each test, nasal volume was measured by acoustic rhinometry immediately after the end of exercise and 10 and 20 minutes thereafter. Results: The rhinometry results showed a significant increase (p<0.001) in nasal volume after physical exercise for all tests performed. At 20 minutes, nasal volume had returned close to resting levels in all three tests. Comparison of the degree of improvement of nasal volume between the three physical tests showed a significant difference (p<0.05) between T1 and T2 (T2 presented gain of 8.3% more in nasal volume than T1). Test 3 showed no significant difference (p>0.05) compared with the other two tests, with 5.8% higher gain in nasal volume observed compared with T1, while the increase was 2.5% lower than in T2. Conclusion: Physical exercise in general causes a significant increase in nasal volume, with the duration of exercise exerting a greater effect on the degree of improvement than intensity.