Laryngeal response to high-intensity exercise in healthy athletes.

Introduction: Exercise-induced laryngeal obstruction (EILO) is a common cause of exertional breathing problems. The current diagnostic approach rests on evaluation of laryngeal obstruction visualised by laryngoscopy performed continuously throughout a maximal exercise test (continuous laryngoscopy exercise (CLE) test) in patients who present with compatible symptoms. Laryngeal responses to high-intensity exercise in endurance athletes are not well described, potentially leading to inaccurate reference values and increasing the risk of misdiagnosing EILO. Aim: To investigate laryngeal responses to high-intensity exercise in a healthy population of endurance athletes with no self-reported perception of respiratory problems. Methods: A cross-sectional study was conducted at Haukeland University Hospital, Bergen, Norway, inviting amateur and professional athletes with no self-reported breathing problems who performed endurance training minimum four sessions weekly. Thirty-six eligible athletes completed a questionnaire detailing exercise habits and past and current respiratory symptoms. They performed a standardised CLE test from which cardiopulmonary exercise data and corresponding laryngeal responses were recorded. The CLE tests were evaluated in retrospect by two independent raters according to preset criteria providing a CLE score. The CLE score rates the severity of laryngeal obstruction during moderate and maximum exercise on the glottic and supraglottic regions on a scale ranging from 0 (no obstruction) to 3 (maximum obstruction). Results: Twenty-nine (81%) athletes (15 females) aged 15-35 years completed a CLE test. Ten participants (33%) had a supraglottic CLE subscore of 2 or 3. Among these, two also had a glottic CLE subscore of 2 or 3. Notably, none had isolated glottic obstruction. Conclusion: In healthy well-trained endurance athletes with no prior perception of respiratory symptoms, the laryngeal response to high-intensity exercise was diverse. Supraglottic laryngeal obstruction was observed in one-third of the athletes. The findings underline that a diagnosis of EILO should rest on observed laryngeal obstruction supported by compatible symptoms.