Altitude tent

An altitude tent is like a big bubble that you sleep inside of. The bubble is special because it has less air in it than the regular air outside. This means there is less oxygen for you to breathe in the tent than there is outside.

When you breathe in air that has less oxygen, your body has to work harder to get the oxygen it needs. This makes your body think it's at a higher altitude, like on a mountain, where there is less oxygen in the air.

Sleeping in an altitude tent can help make your body stronger and better at using oxygen. Lots of athletes use altitude tents to help them train before big competitions because it makes them better at using oxygen and helps them do better in their sports.