Madonna has bought oxygen machines for each of her homes.

The singer gives herself regular oxygen facials to improve her complexion, as well as using the machines to provide extra energy when she suffers from jet lag.

"You can take the oxygen machine and inhale if you're feeling really tired or jet-lagged, which is one of the reasons I have them at home," Madonna told a German magazine. "You just lie down for 10 minutes and put it in your nose. They are really great."