Effect of yoga (unilateral nostril breathing) on autonomic nervous system activity in medical students – A randomized parallel group study

ABSTRACT

Background: Practice of Pranayama and “swara” have been found to affect cardiovascular, respiratory, and autonomic functions. The regulation of autonomic functions in a positive direction helps reduce anxiety and stress. Studies have suggested that right and left nostril breathing produce specific autonomic changes. Aim and Objectives: The aim of the study was to find the relationship between right unilateral nostril breathing (RUNB) and sympathetic arousal and that between left unilateral nostril breathing (LUNB) and parasympathetic arousal. Materials and Methods: This is a randomized parallel-group study. Fifty consenting students were chosen by simple random sampling technique and divided into two groups of 25 each, randomly. One group was made to practice RUNB and the other, LUNB for ten minutes daily for 2 months. Systolic blood pressure (SBP), diastolic blood pressure, mean arterial pressure, heart rate (HR), and respiratory rates were measured before and after the intervention. Results were analyzed using SPSS version 21. Comparisons were made by conducting a repeated-measures ANOVA. Results: The RUNB intervention contributed statistically significant changes in SBP and HR after 2-month practice. LUNB did not result in statistically significant changes in the studied parameters. Conclusions: RUNB was found to have significant sympathetic arousal but LUNB could not be linked to parasympathetic arousal.