Breath, The New Science of a Lost Art by James Nestor
I just finished this book and it is bristling with sticky note tabs. As far as maintaining health and well being I think the breathing techniques discussed in this book good go a long way toward furthering the tools of a Green Wizard's physical, mental and spiritual tool box. Nestor combed many ancient sources to discover that correct breathing was the key to good health, mental and physical, and spiritual development. The book is also a pretty good read.
Nestor's website, https://www.mrjamesnestor.com/breath, has many links and video's to other useful sites for learning the many breathing techniques discussed.
PS If you are following the discussion on Dreamwidth, ttps://ecosophia.dreamwidth.org/123464.html, Nestor mentions this book as part of a Yogic lung expanding technique. I thought this was a useful coincidence.