Your heart is continuously beating to keep blood circulating throughout your body;it’s rate is changes depending on your activity level! It’s us usually low when your resting or sleeping and higher when your doing exercise and also during exercise your body may need three or four times your normal cardiac output, because your muscles need more oxygen when you exert yourself.
(Your heart typically beats faster so that more blood gets out your body)
I hope this helps if you any more questions don’t hesitate to message me :)
**I have done my research from multiple websites and i this is my answer