The Impact of Isotonic Seawater on Subjective and Objective Nose Patency in Athletes: A Randomized Controlled Trial

Background/Objectives: Nasal irrigation with isotonic seawater is a known and oft-used treatment for nasal obstruction in patients with acute and chronic nasal inflammatory disease undergoing therapy with intranasal corticosteroids and antihistamine drugs. Nasal patency in healthy athletes is extremely important; however, to date, the effect of isotonic solutions for nasal irrigation in healthy athletes has not been tested. This randomized controlled trial aimed to investigate the potential synergy of physical exercise and nasal isotonic seawater on airflow and the subjective assessment of nasal patency in healthy, high-level athletes. Methods: The intervention group included 33 healthy athletes who used an isotonic seawater nasal spray daily, with a control group including 31 healthy athletes who did not use any sprays; both groups underwent identical seven-day training periods. The primary outcome measures were subjective NOSE questionnaire scores and secondary peak nasal inspiratory flow (PNIF) measures, while anthropometric and demographic variables were covariates. Results: A significant decrease in subjective nasal resistance scores was observed in the intervention group compared to the control group (binary logistic regression model, p = 0.006, RR 7.695), both in the first and second measurement interval. This effect increased with time (Friedman's two-way analysis of variance, p < 0.001). Peak nasal inspiratory flow is positively affected by exercise but not by isotonic seawater spray intervention. Conclusions: The effects of nasal isotonic seawater irrigation during intense athletic training are beneficial on subjective nasal patency in the short term, while the effects on objective nasal patency are less clear.