A warm-up should be about .

5-10 minutes

Explanation:

This is long enough to make your muscles regulate blood flow, without wearing them down too much. Please give me Brainliest, I am really young but have been working as hard as I can and haven't got it yet :)

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.