Mystery #3Tier 2body / lungs
Why do you breathe faster when you run?
Sprint across a playground and within seconds you're puffing and panting, your chest heaving. Sit still and your breathing is slow and quiet. Why does moving make you breathe so much harder?
Your guess
What's your hunch about why your lungs work so much harder when you run?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.