Why is it more difficult to hold your breath after exhaling? Isn’t exhalting just getting rid of CO2 and isnt most of the oxygen absorbed by our lungs withing seconds after inhaling?

Question

Why is it more difficult to hold your breath after exhaling? Isn’t exhalting just getting rid of CO2 and isnt most of the oxygen absorbed by our lungs withing seconds after inhaling?

In: Biology

Answer 1

No. You only take like 10-20% of oxygen out of the air.

Otherwise mouth to mouth rescue breathing would not work.