I will add that success at randonneuring starts and ends with eating. It's not easy, and things often fall apart and I can't eat as much as I need to on a ride. This year's 400k was a good example, I could barely eat after the 200k mark and I felt numb when I was about 30 miles from the finish. I do things like fasted riding to try to get fat adapted. I have been reasonably successful at making it so I can ride a long way without eating much.