Here’s a fascinating article titled 
comparing two of the most popular Breath practices which have completely different effects on the mind & body –Buteyko and Wim Hof Method.
“Ever since I founded Conscious Breathing in 2009, people’s interest in breathing as a health promoter, performance enhancer and a way to personal and spiritual growth has increased more and more, which brings me much joy. In yoga, meditation, mindfulness, and qigong, different breathing techniques are central. Perhaps you’ve heard of the Buteyko breathing method? It’s a Russian method that is spreading across the globe, founded by the late Professor Konstantin Buteyko. Rebirthing and Holotropic breathing are two other popular ways of using breathing to change the state of mind and improve one’s health.
One of the methods that has attracted the most interest is the Wim Hof Method. Therefore, a common question is what makes Conscious Breathing different from Wim Hof breathing. Which way to breathe is correct? Which method is best? Is it possible to combine the two?”
Full article: https://www.consciousbreathing.com/blogs/co2-academy/how-should-i-breathe-wim-hof-vs-conscious-breathing
