The Acute Therapeutic Effect of Bhramari Pranayama on Autonomic Function and Self- Reported Anxiety

The United States is in the midst of a mental health crisis. Individuals are navigating an increasingly complex world during a global pandemic that offers no shortages of uncertainty. Continuous daily stressors accumulated over time without adequate self-regulation measures are exhausting people and promoting disease, both psychological and physiological. One tool that may better equip individuals to manage their mental health and potentially provide numerous health benefits is breath modulation or breathing exercises. The evidence is becoming clear that breathing practices can provide a wide range of practically significant benefits, though evidence for specific methods and results is limited. Purpose: This study compared the changes in heart rate variability (SDNN, rMSSD, HF power, LF power), blood pressure (Systolic, Diastolic, MAP), and anxiety level (STAI) resulting from a five-minute practice of Bhramari Pranayama, a specific breathing exercise involving a hummed exhalation, and a five-minute slow breathing practice. Methods: Twenty healthy adults (10 females, 10 males) participated in a within-subject crossover study to measure effects from both breathing conditions. Data were gathered with a heart rate monitor, automated sphygmomanometer, and through self-report. Repeated measures analysis of variance models were used to examine mean-level differences in outcomes over time between breathing conditions. Results: Both breathing conditions improved HRV measures over time (SDNN [P<.001], rMSSD [P=0.03], LF power [P<.001]) with the exception of HF power (P≥.362). However, no significant time x breathing condition interaction effects were present for HRV outcomes (each P≥.155). No significant effects were observed between breathing conditions or over time for blood pressure measures (each P≥.108). For self-reported anxiety (measured with the STAI), the time x breathing condition interaction effect (P=.062) and time effect (P=.084), trended towards statistical significance, indicating that Bhramari Pranayama may produce more potent anxiety-reducing effects compared to slow breathing. Conclusion: Both breathing methods examined may improve HRV indices during practice, while Bhramari Pranayama may more effectively reduce feelings of anxiety. Neither breathing method demonstrated efficacy in reducing blood pressure