A recent article on recovery in Bicycling magazine says that most people don't put the same kind of planning and care into recovery that they do when they plan the active portions of their training. Not only is sleep absolutely fundamental, they also say that the best results come from super-easy recovery activities. Cross-training can be effective if it targets different muscles, but if you're doing recovery rides they need to be at "embarrassingly slow, let-your-grandmother-beat-you" speeds. That's hard for me to do psychologically for some reason. If I'm not pushing myself on a ride, I feel at some fundamental level it's a waste of time. Yesterday I made a deliberate effort to get past that, and did my best to maintain a high-rpm, low-speed ride for 20 miles or so. I think it helped, especially since the day had already included a 3 mile run and some yard work.