Comment by lj3

Why do you suppose your legs went from 60% to 2% so rapidly? Do you think your muscle really depleted in function that quickly, or did your brain cut off the electrical signals to the leg in order to protect it from permanent damage?

But you're correct in that there is more to it. Adrenaline masks fatigue. It allows you to temporarily exceed what your brain would normally allow you to do in order to save your life. You pay for it later, though.