A Functional Near-Infrared Spectroscopy Study of High-Frequency Yoga Breathing Compared to Breath Awareness
Shirley Telles, Ram Kumar Gupta, Nilkamal Singh, Acharya Balkrishna
Department of Yoga Research, Patanjali Research Foundation, Haridwar, India
Med Sci Monit Basic Res 2016; 22:58-66
High-frequency yoga breathing (breath rate of 2.0 Hz) has been associated with changes in oxy-hemoglobin in the prefrontal region of the brain. The present study assessed the effects of high-frequency yoga breathing (HFYB) at 1.0 Hz on frontal oxy-hemoglobin (oxy-Hb) and deoxy-hemoglobin (deoxy-Hb).
MATERIAL AND METHODS: Forty healthy male participants were recruited for the study. The experimental group consisted of 20 participants 23–40 years old (group mean ±S.D., 26.4±4.7 years) with at least 3 months of experience performing HFYB (group mean ±S.D., 16.3±9.8 months). The control group consisted of 20 participants ages 23–38 years (group mean age ± S.D., 27.4±4.1 years), who were seated quietly for the same duration and their average experience of yoga practice was (±S.D.) 4.3±2.7 months. Each participant in the experimental group was assessed at 2 sessions (HFYB and breath awareness [BAW]) on alternate days. Hemodynamic changes were assessed using a functional near-infrared spectroscopy sensor placed over the forehead. Data were analyzed using repeated-measures analyses of variance followed by post hoc Bonferroni adjustment.
RESULTS: A significant reduction was observed in oxy-Hb during and after HFYB on the left and right sides compared to values before. We also found a significant reduction in deoxy-Hb during and after the quiet sitting control session compared to pre-session values on left and right sides.
CONCLUSIONS: The decrease in oxy-Hb during and after HFYB suggests that there was no frontal activation during HFYB when practiced at the rate of 1.0 Hz.
Keywords: Cerebral Arteries, Hemodynamics, Yoga, fNIRs, Meditation