As with many other aspects of holistic health, it's incredible how Western medicine has ignored verifiable scientific evidence about the wide range of health benefits one can derive from these breathing techniques.
A smattering of advice from the book:
* Breathe through your nose, NOT your mouth (except when talking).
* Breathe slowly, softly, not (necessarily) deeply. Optimal breath rate is roughly 5.5s inhale, 5.5s exhale, 5.5 breaths per minute, 5.5 L of air inhaled.
* * Many people tend to over-breathe, which has a number of detriments, including stimulating anxiety.
* As with most aspects of health, the body does best with most-of-the-time low stress (see above "Breath slowly") punctuated by short intense intervals of high stress. Wim Hof breathing is the high stress workout that exercises your breathing system and builds breath flexibility.
* Chew tough stuff, exercise your jaw. This can help build wider mouths (new bone growth!) and open up your airways.
[0] https://www.amazon.com/Breath-New-Science-Lost-Art/dp/073521...