Abstract
BACKGROUND: Traditional yoga texts describe "cross nostril breathing," with inhalation and exhalation through different nostrils. Previous research reported no clear differences in oxygen consumption during uninostril breathing (i.e., inhalation and exhalation through the same nostril), hence not supporting right and left uninostril breathing as activating or relaxing, respectively, with no research on oxygen consumed in "cross nostril breathing." METHODS: Oxygen consumed during "cross nostril breathing" was measured in healthy participants (n = 47, males, 26.3 ± 6.4 years). Five sessions (viz., right nostril inspiration yoga breathing [RNIYB], left nostril inspiration yoga breathing [LNIYB], alternate nostril yoga breathing [ANYB], breath awareness (BAW), and quiet rest (QR) were conducted on separate days in random order. Sessions were 33 min in duration with pre, during, and post states. RESULTS: Volume of oxygen consumed (VO(2)) and carbon dioxide eliminated (VCO(2)) increased during RNIYB (9.60% in VO(2) and 23.52% in VCO(2)), LNIYB (9.42% in VO(2) and 21.20% in VCO(2)) and ANYB (10.25% in VO(2) and 22.72% in VCO(2)) with no significant change in BAW and QR. Diastolic blood pressure decreased during BAW and QR and after all five sessions (P < 0.05; in all cases). All comparisons were with the respective preceding state. CONCLUSION: During the three yoga breathing practices, the volume of oxygen consumed increased irrespective of the nostril breathed through, possibly associated with (i) conscious regulation of the breath; (ii) attention directed to the breath, and (iii) "respiration-locked cortical activation." Restriction of the study to males reduces the generalizability of the findings.