Why do we breathe?

In and out, all day and all night, you breathe without even thinking about it. You can’t see what you breathe — so why does your body need it so much?

Air has a special gas inside

The air around you holds a hidden gas called oxygen. You can’t see it or smell it, but every part of your body needs it to work — to run, to think, even to grow. When you breathe in, you pull that oxygen inside you.

Your lungs do the work

Inside your chest are two soft, spongy lungs. When you breathe in, they fill up like balloons and grab the oxygen from the air. Your blood then carries it all around your body. When you breathe out, your lungs push out a different gas, called carbon dioxide, that your body is finished with.

Breathing faster when you play

When you run and jump, your busy muscles need more oxygen, so you breathe faster and your chest goes up and down quickly. When you rest, you don’t need as much, so your breathing slows down again and turns calm and quiet.

Wonder fact: You breathe in and out about 20,000 times every single day — and you do nearly all of it without ever thinking about it!