How is breathing low oxygen saturated air more dangerous than holding your breath?

Question

I’m doing emergency rescue for work and learnt that inhaling a few times at below 10% oxengenated air will leave you pretty much immobile, but I can hold my breath for at least a minute, so shouldn’t I be able to go without 02 for a similar amount of time? Sorry if this is smoothbrained, I tried googling it and couldn’t find an answer for this specifically.

In: Biology

Answer 1

When you hold your breath you have a lung full of 21% oxygen. You can’t possibly hold your breath long enough to deplete your lungs of oxygen and, therefore your blood oxygen will remain adequate to feed your brain. Breathing 10% oxygen will quickly lower your blood oxygen levels to brain-dangerous values.