Assessing if Dysfunctional Breathing is associated with performance in endurance athletes

<bold>Background:</bold> The presence of Dysfunctional Breathing (DB) has been proposed to negatively impact performance in endurance athletes; however, this remains unclear. <bold>Aims:</bold> To assess the presence of DB in long-distance runners and comprehend which outcomes of DB are associated with poorer performance. <bold>Methods:</bold> Adult runners in the top 25% of their respective sex and age categories were assessed using the Nijmegen Questionnaire (NQ) and Hi-Lo Breathing Tool (Hi-Lo). The NQ evaluates hyperventilation symptoms, and the positive cutoff score is ≥ 19. Hi-lo is a manual assessment that determines thoracoabdominal patterns. Individuals were assessed prior to their training session or competition (ranging from 10km to marathon), and the running pace (in seconds/km) was obtained from every athlete's official competition results. <bold>Results:</bold> Ninety runners were enrolled in the study; 63% were males. Twenty-nine percent of all individuals tested positive for DB; 21% were classified using Hi-lo, 2% using NQ, and 6% tested positive in both assessments. No significant difference in running pace was observed between athletes based on the presence of DB. However, a positive linear correlation was observed between the running pace and the specific scores for the questions "feeling of tension" and "anxiety" obtained in the NQ (p=0.03 and 0.01, respectively). <bold>Conclusion:</bold> Our findings suggest that DB, assessed by the total score of NQ or the Hi-lo, is not associated with performance in high-level runners. However, athletes reporting perceptions of tension or anxiety may present worse performance.