I posted an info-graphic on recovery of high performance athletes and the need for lots and lots of sleep. Here's a graphic journal of a workshop where sleep was emphasized to improve creativity. (Plug here for the graphic artist, Deb LeFrank) It turns out that sleeping in is encouraged!
The Huff Post has a bunch of articles about the importance of sleep.
Why have I spent my life getting up at 5am to row? It is gorgeous to be on the water and watch the sun rise - but I'm rethinking the balance of doing that every day. I'm building more sleep into my routine!