Rosalba Courtney, N.D., D.O., and Marc Cohen, M.B.B.S.

RMIT University, School of Health Sciences, Bundoora, Australia

Background:
The practice of yoga breathing techniques is thought to improve the efficiency and stability of breathing and improve breath-holding time (BHT). While shortened BHT has been observed to accompany breathing disturbances, protocols for measuring this have not been standardized.

Russian physician, Dr. Buteyko developed a method for measuring BHT and proposed that increased BHT indicates an improvement in breathing efficiency and general The Buteyko breathing technique which is based on this premise has since been promoted as a treatment for asthma and has been shown to improve asthmatic symptoms without changing lung function.

The current study aimed to assess BHT and lung function in a group of advanced yoga practitioners and in non-practitioners before and after an intensive yoga program.

Methods:
Spirometry and BHT measures were performed on a group of 10 males aged between 40-60 attending an intensive residential yoga program in Bangalore, India and a group of long-term (20-40 year) yoga practitioners who were also interviewed about their practice and respiratory health. BHT was recorded according to the Buteyko method and to physiological breaking point as indicated by involuntary diaphragmatic motion.

Results:
BHT using both techniques increased substantially in 80% of participants after the yoga intensive, approaching the levels found in long-term yoga practitioners. Only slight improvements were seen in lung function although one case showed dramatic improvement.

Two long-term yoga practitioners that previously had asthma and believed themselves cured were observed to have moderate to severe airway obstruction on spirometry.

Discussion:
Improvements in BHT after yoga practice may indicate a training effect and alteration in chemoreflex related to relaxation and reduced minute ventilation rather than improved lung function.

The evidence of airway obstruction without subjective symptoms in long term yoga practitioners was a startling finding although in keeping with what has been observed by others.