Eli5 Why do we become out of breath and start breathing heavy if we do something exhausting if we are always breathing air in and out?

Question

I don’t get how we get out of breath if we are breathing air into our lungs all the time.

In: 0

Answer 1

When you’re at rest you’re breathing just fast enough to keep your body’s fuel needs met. As soon as you start exerting yourself your muscles need more fuel, so you start breathing faster. The same as how a car engine needs to run faster to speed down the highway than it does to idle in park.