Short-Term Effects of Nostril-Regulated Yoga Breathing on Autonomic Variables: A Randomized Crossover Trial

Area of Science:

• Physiology
• Yoga Research
• Autonomic Nervous System

Background:

• Autonomic nervous system (ANS) responses to yoga breathing (pranayama) show variability.
• Nostril dominance at rest may influence these ANS responses.
• Traditional yoga texts suggest physiological differences based on nostril dominance.

Purpose of the Study:

• To investigate the effects of different nostril-dominant breathing techniques on autonomic variables.
• To determine if baseline nostril dominance modifies the physiological responses to yoga breathing.
• To compare uninostril and alternate-nostril breathing with breath awareness and rest.

Main Methods:

• Forty-five participants underwent five 15-minute sessions: right-uninostril, left-uninostril, alternate-nostril breathing, breath awareness, and quiet rest.
• Nostril patency was assessed using the Zwaardemaker method before each session.
• Autonomic variables measured included heart rate variability, blood pressure, respiration, galvanic skin conductance, finger plethysmogram amplitude, and state anxiety.
• Generalized linear mixed-model analyses were used, considering baseline nostril dominance.

Main Results:

• In right-nostril dominant individuals, left-uninostril breathing increased heart rate variability (RMSSD, HF-HRV) and decreased systolic blood pressure.
• Left-uninostril and alternate-nostril breathing decreased systolic blood pressure in right-nostril dominant individuals.
• State anxiety scores decreased across all breathing interventions and quiet rest, regardless of nostril dominance.
• Unique effects of uninostril or alternate-nostril breathing were evident only when baseline nostril dominance was considered.

Conclusions:

• Baseline nostril dominance is a crucial factor influencing autonomic responses to specific yoga breathing techniques.
• Left-uninostril breathing and alternate-nostril breathing appear to induce relaxation in right-nostril dominant individuals.
• The study supports traditional yoga assertions regarding physiological differences linked to nostril dominance at rest.