A Literature Review

Allison N. Abel, Lisa K. Lloyd, and James S. Williams.
The Journal of Alternative and Complementary Medicine. March 2013, 19(3): 185-190. doi:10.1089/acm.2011.0516.

Overall, pulmonary function appears to improve with a minimum of 10 weeks of regular yoga practice, and the magnitude of this improvement is related to fitness level and/or the length of time the subjects spend practicing pranayama (i.e., breathing exercises). In other words, greater improvements in pulmonary function are more likely to be seen in less-fit individuals and/or those that engage in longer periods of pranayama. Additional studies examining various yoga practices are warranted to gain a more comprehensive understanding of the effects of yoga techniques on pulmonary functions.

Journal Reference:  http://online.liebertpub.com/doi/abs/10.1089/acm.2011.0516