OK, OK, so here is what I know as an expert in getting really bad cramp. If I ride to my limits (which reduce in cold weather) I will cramp in muscles in my legs, usually thigh muscles, but as I get more fit, my range extends before it hits, but as I progress a defined muscle group in both legs will ‘sing’. So once they have had their 15mins of pain ( read: me rolling around in agony) they will be fine on the following ride, and an alternate muscle set ( in both legs will have their say.
So what effect does salt, isotonics or bananas have on this…they give me greater range, but I find hydrating before exercise also helps. Nuun helps with post ride head aches like no other. They are magic.