Nasal functional modifications after physical exercise: olfactory threshold and peak nasal inspiratory flow

Statement of problem: The respiratory nasal effects of physical exercise have been extensively investigated; on the other hand there are no data regarding olfactory threshold modification after aerobic physical exercise. Methods: The present prospective study investigated the modifications in nasal respiratory flows and olfactory thresholds after controlled aerobic physical exercise in a cohort of 15 adult, healthy volunteers. The Peak Nasal Inspiratory Flow (PNIF), and the Sniffin\u2019 Sticks olfactory threshold test were used for our determinations. Main results: The mean PNIF after physical exercise was significantly higher than the mean PNIF value found before physical exercise. Statistical analysis ruled out any significant difference between mean olfactory thresholds pre vs post physical exercise. Principal conclusions: These outcomes confirmed PNIF sensitivity and reliability also in determining the changes in nasal patency occurring after physical exercise. The active vasoconstriction of nasal mucosa associated with the reduction of blood flow to the olfactory epithelium due to physical exercise may be compensated for by the increase of olfactory molecules that reach the olfactory mucosa because of nasal mucosal shrinkage: this mechanism could explain the stability of mean olfactory threshold after physical exercise