The pop diva was using the high-tech machines to give herself oxygen facials, which she says help her maintain a porcelain doll-like complexion.
But she later discovered inhaling the pure air helped reduce her tiredness. The jet-setting singer also believes breathing oxygen helps her beat jetlag.
She told a German magazine:
"You just lie down for ten minutes and inhale."
Madonna's publicist, Liz Rosenberg, has confirmed the star's love of the unusual treatment.
"She loves the machine. It's phenomenal. I want to try it myself."
Last month, Madonna sparked health fears after friends claimed she was looking skinny and exhausted.
The 47-year-old's pals were reportedly worried she was taking her punishing exercise regime too far - and was jeopardising her health.
A source said at the time: "She looks way too thin. It's scary. Everyone around her is buzzing that she's working herself right into exhaustion."
Madonna is said to be following a gruelling fitness programme, including two to three hours a day of yoga and Pilates, plus swimming, weight training and