The word aerobic means "with oxygen". Physical activities that really get your heart pumping are called "aerobic" activities because your muscles use a lot of oxygen when you do them. These heart-pumping activities also make you breathe faster so your lungs can send more oxygen to your muscles!

These heart-pumping activities are aerobic ones!

Clench your fist and look at it. This is the size of your heart.

Your heart is one big muscle and cannot become stronger by itself. It depends on you to keep it strong. Doing fun aerobic activities helps your blood carry more oxygen.

Aerobic activities even help the blood move easier throughout your blood vessels!

Aerobic activities are continuous and use the body's large muscles, like your legs and arms.

If you do many aerobic activities, you will notice that you can play for a long time without getting tired!

You may have heard people talking about "cardio" activities. Aerobic and cardio are synonyms. Another word for these activities are endurance activities.

You can measure how hard your heart is working by taking your pulse! Pulse measures the number of times your heart beats. We often measure it on the wrist.

It's easy to do aerobic activities because they are some of our favorites:

Look at Stephanie playing soccer!

Blading

Swimming

Tag

Look at Kelly playing volleyball!

Running

What is your favorite aerobic activity?