Your Heart and Circulation

Did your pulse beat change after you did the Jumping Jacks?

When muscles work they need oxygen.
Oxygen for the muscles is carried in the blood.
If the muscles work hard they need extra oxygen so the heart pumps blood a bit faster through the arteries and veins and to the muscles.

Did you know?

The heart is a powerful enough muscle to propel blood to all these places at a notably high speed and pressure.

The heart is an involuntary muscle. You can't contract it when you want like you can with your biceps. Hormones, however, can trigger it to pump faster or to relax