Respiratory modulation of neurophysiology and symptoms in athletes with sports-related concussion: a randomized crossover trial.

Objectives: This study examined the effects of two breathing interventions on athletes with persistent post-concussive symptoms. Resonance breathing (RB) is a slow breathing technique at an individual's resonance frequency. Pelvic floor resonance breathing (PRB) combines diaphragmatic breathing with pelvic floor muscle activation. Methods: A randomized crossover trial was conducted using a 3-1-3 week design. Two intervention phases were separated by a 1-week washout period. Twenty-six male rugby athletes with persistent post-concussive symptoms were included. Participants were assigned to different intervention sequences. Outcomes included the Rivermead Post-Concussion Symptoms Questionnaire, electroencephalography (EEG), heart rate variability (HRV), and skin sympathetic nerve activity (SKNA). Measurements were taken at baseline and after each intervention. Results: Total symptom scores decreased after both interventions ( Conclusion: Both RB and PRB were associated with symptom improvement and changes in neuro-autonomic function. The two interventions showed different patterns. These findings support the use of breathing interventions as non-pharmacological approaches in concussion rehabilitation.