Hope this is the right forum to ask this. I recently got back into riding bicycles and would like to make a long ride from Miami to Key West. (150 miles.) I've only done 20 mile rides so far and I do them with ease. Still I know just doubling up to 40 miles might make a huge difference to my butt if not my whole body. I expect 150 might be much worse. Any suggestions on a simple regimen to prepare?