C-Net reports that Michael Phelps wears high compression pajamas to bed.
"...The Recharge Energy Suit is a full-body suit designed to help the body recover from fatigue after training...."
"...Under Armour claims the super tight compression fit pushes out the water damaged muscle fibers take on when sore, leading to a faster recovery. This is also probably as close as you'll get to knowing what it feels like to be swallowed by a snake. ..."
[Link]I find this product patently absurd but I bet Speedo jumps in if there is a market.