[Henk0]

Chiming in with others who responded, I haven’t experienced decreased heat sensitivity or increased sweating either. On a physiological level, what the cold training (cold showers, winter walks, ice baths which I’ve yet to get into) seems to do is exercise the small muscles which control blood flow in the skin, training them to respond more efficiently to changes in temperature. As for the breathing exercises, the effects seem to come from a combination of co2 tolerance training (co2 levels being the primary trigger of air hunger and the breathing reflex), hypoxia training (cells having to adapt to regularly operating with lower levels of oxygen), diaphragmatic training (in-breaths are strong and forced), and the rapid shifting between sympathetic (forced inbreaths) and parasympathetic (relaxed outbreaths and empty(ish) lung breath holds) activation. Both the breathing and the cold exposure are basically hormetic stressors, like weight training. Another aspect of the cold training is psychological. Regularly committing to doing something that is inherently aversive, sticking to it, and training oneself to breathe calmly while doing it. I’ve definitely noticed a reduction of general and social anxiety levels. This is super apparent if I have a cold shower before a social gathering or a job meeting. Massively improved confidence. The immediate effect of a few minutes cold shower is an adrenaline rush, likely followed by endogenous endorphine release. It’s an ecstatic feeling and a huge energy and mood booster