Hypoventilation Yoga Exercises: Effects on Respiratory Metabolism

Abstract

Aim. Assessment of changes in respiratory metabolism and parameters of external respiration during hypoventilation yoga exercises. Material and methods. 22 experienced volunteers (18 men and 4 women, mean age 42.95 ± 8.14 years) performed yoga breathing exercises with a frequency of 3 times per minute, 1.5 times per minute, 1 time per minute, as well as free breathing for 2 minutes. Respiratory rate (RR), minute ventilation (MV), tidal volume (TV), partial pressure of CO2 in expired air at the end of exhalation (PetCO2), percentage of O2 in expired air (FeO2) and hemoglobin saturation (SpO2) were recorded. Results and discussion. The breathing regimen with RR = 3 times / min is hyperventilating, accompanied by a statistically significant increase in respiratory minute volume (RMV) and a decrease in PetCO2; hemoglobin saturation indices are not changed. Breathing with a frequency of 1.5 times/min is accompanied by a statistically significant decrease in RMV compared to the rest state, as well as an increase in PetCO2 and a decrease in FeO2, that is, it is hypoventilating, although there is a certain heterogeneity within this subgroup depending on the recruited tidal volume. Indicators of hemoglobin saturation with a given breathing mode do not change. The breathing regimen with RR = 1 time / min is accompanied by a statistically significant decrease in the RMV, an increase in PetCO2 and a decrease in FeO2; the average values of hemoglobin saturation do not change, but the minimum saturation values (observed once during each respiratory cycle) are statistically significantly lower than at the rest state. These results suggest that hypoventilating yoga exercises may have a positive effect on cerebral blood flow and cerebrovascular reactivity. Conclusion. Performing yoga breathing exercises at the respiration rate of 1.5 and 1 times per minute is accompanied by statistically significant hypoventilation, alveolar hypercapnia and hypoxia.