R&R is about as important as it gets for the serious lifter. Many think that the time you spend hammering your body is the gym is the only thing that matters. Crushing iron breaks down muscle and that's half the battle. But the other half is just as critical, if not more. Unless you give your body adequate rest, your muscles won't have a chance to grow. That's right. Your muscles grow outside the gym. So treat your body with respect. Give it the rest it needs.

For a discussion about rest, check out this thread: http://forum.animalpak.com/showthread.php?t=4765

For a thread talking about the importance of sleep:
http://forum.animalpak.com/showthread.php?t=523