You have about 10 quarts of blood in your body. At REST your heart pumps about 5 quarts each minutes. That is half of your blood volume per minute. During exercise it can pump 40 quarts per minute. How many times does all of your blood complete the cycle around your body during exercise?

8 times

Explanation:

Given that You have about 10 quarts of blood in your body. At REST your heart pumps about 5 quarts each minutes.

That means the heart will pump 10 quarts in 2 minutes.

That is half of your blood volume per minute.

If during exercise it can pump 40 quarts per minute, that is, 80 quarts in 2 minutes.

To know how many times does all of your blood complete the cycle around your body during exercise, you must divide 80 quarts by 10 quarts. That is,

80 / 10 = 8

Therefore, your blood complete the cycle around your body 8 times during the exercise.