Wim Hof (Inner Fire)
http://www.icemanwimhof.com/innerfire http://www.innerfire.nl/home
Stig Severinsen (Breathology)
https://en.wikipedia.org/wiki/Stig_Severinsen https://www.breatheology.com/ https://www.breatheology.com/free-gift/ https://www.breatheology.com/free-breathing-video1/