And the muscles. You can’t fight or flight if you have to ask the liver to deliver glycogen. That’s how anaerobic exercise works. You have the fuel but not enough oxygen to burn it so you burn it fuel rich and oxidizer poor.
The grandparent means something a bit different. Muscles can use glucose without _oxygen_ to get short bursts of energy quickly by rearranging glucose molecules (indirectly) into lactic acid.
