system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come you will start getting brain damage after 6 minutes with no oxygen, but the world record for holding your breath is 22 minutes?

Thanks for the replies!
gpt
The air you inhale is ~21% Oxygen the air you exhale is 13-16% oxygen, Hold your breath for 60 seconds with a blood oxygen meter on and you find that there is zero change in the amount of oxygen your blood is carrying. Hold for another minute and your blood oxygen level will only drop a few percent. The urge to breath becomes intense very quickly because your body doesn't actually have anyway to sense the amount of oxygen in your blood but rather senses the build up of CO2, as your oxygen level drops your body will start to restrict blood flow to the extremities this (not the actual lack of oxygen) is what causes your fingers or lips to tingle when you are extremely out of breath. 

Your body can also power many systems anaerobically (without oxygen) your muscles can use more energy less efficiently and with more waste (lactic acid) for quite some time the only vital part of you that lacks this ability is your brain. Now all this adds up to the ability to hold your breath for about 7 or 8 minutes with proper training, the record you are referring too is a pure O2 record where the diver holds their breath after breathing pure medical grade oxygen which again doesn't reduce the feeling of needing to breath at all but does allow you to hold much longer.