Running/hiking in the winter in nothing but shorts isn’t that bad, if you keep moving and wear gloves. With the wind chill, biking’s cold enough as is. I find I unintentionally wim hof myself most of the winter by not wearing quite enough clothing anyways. My brown fat stores have grown out of pure stupidity and unpreparedness.
I tried cold showers for a bit after reading ‘what doesn’t kill us’, but found that after a 3+hr bike ride in the cold and constant wind…the absolute last thing I wanted to do was take a cold shower, no matter the long term or training benefit. It’s fine and easily manageable after a summer ride or indoor trainer session though.
Didn’t try any breathing stuff. Would definitely be interested in a Chad deep dive.