Walk your bike a bit during the course of a long, touring day.
I had walked my LOADED touring bike up a few of the steep hills in eastern KY and VA. (Why doesn't anyone else ever admit to this?) Although I did it because I was simply tired, I found that after walking, my muscles and body simply felt better.
Walking for while (whether on hills or the flats) makes you use your muscles differently than riding, allowing them to be stretched and soothed a bit. Plus, you get the pressure off of your butt and Mr. Happy for a while.
One way to rest is to stop and sit a while. Another is to simply walk; but you're still moving, still expending calories, and really helping your body to continue the ride.
David in PA (FL)