How much of an effort are you making while riding those thirty miles? Doing it at a leisurely pace or trying to keep at what you feel is near the maximum effort you can maintain?
Leisurely, then all you really need to think about is hydration.
If at a high effort, then you need to think about hydration and replacing those spent Calories and electrolytes. If you only drink water, then you need some foods with carbs and electrolytes. Or you can put the carbs and electrolytes in your water. Some want some protein, but I'm not convinced on that yet, but if you feel better with a little protein, then go for it. And this is only while you ride, not quite the same for after.
Muscle cramping tends to indicate you might have flooded yourself out on pure water. IMO as is just about everything I write.
Last edited by Iride01; 07-15-19 at 09:16 AM.