Natural. Is the correct answer :)
However, when necessary, such as during exercise, your heart can pump up to four times that amount per minute". In the long term, maintaining good physical fitness will help to lower your resting heart rate by improving your heart's ability to pump blood around the body more efficiently.
Explanation:
the answer is the aerobic exercise. when first starting a regime, drs agree that you should start at a slower pace for safety and building up to a more intense exercise, when you gain strength.