While we all practice breathing since birth I do believe that trying some advanced techniques could be dangerous. See https://zeta.blue/physiology for possible effects.
People have unique physiological, and mental limits. As a toy example we could imagine someone holding their breath until they pass out and fall.
>we could imagine someone holding their breath until they pass out and fall.
It is not easy to imagine this. Brain have protective mechanisms in place to prevent this. If someone is holding their breath for too long - they start experiencing an immense, primal fear which magnifies tenfold every second. It is close to impossible to consciously bear that fear and continue holding your breath – every other second requires years of practice. You will inhale, if you can. Your body simply wont let you fail or pass out.
People have unique physiological, and mental limits. As a toy example we could imagine someone holding their breath until they pass out and fall.