Why does my foot feel like it is on fire when I'm trying to sleep

A burning sensation in your feet may be caused by nerve damage in the legs, also called neuropathy. Although many medical conditions can cause burning feet, diabetes is the most common. Most burning feet treatments focus on preventing further nerve damage and reducing pain.

Explanation:

i believe it is the last one. im sorry if im wrong!

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.