Wim hof seems derivative of some yogic breathing practices that have existed for a while. I have learned one of them (and then another one at a later stage in my life for migraines) and can vouch for good long term effects for either one, they are: 1) Sudarshan Kriya by Art of Living foundation 2) Shambhavi kriya by Isha foundation

IMO both of these are better integrated with pranayam.