What Michael sleeps in

The Michael Phelps brand is protected even when he's sleeping.

The 27-year-old swimmer, the most decorated Olympic athlete is history, sleeps in high-tech compression pyjamas that massage every single one of his overworked muscles.

"The older I get, the more I have to pay attention to the smaller things that make a difference," Phelps says in an interview with Yahoo Sports, sounding almost like the rest of us.

"For me, recovery is so big."

Under Armour, which makes the $130 Recharge Suit, pays Phelps an estimated $15 million in sponsorship fees. But he does actually use the product, a lot.

"I swim, I get a message, I get an ice bath, I put it on," he says. "I take a nap with it on. I sleep in it.

Under Armour product designer David Ayers says the suit's lattice weave, a sort of Spiderman motif, squeezes all the major and minor muscles simultaneously so "those off days go away."

AP/Italian swimmer Federica Pelligrini gets a hand putting on her compression suit after practice at the London2012 Games on July 27.