Nelie - I experience cramps in my neck when I am dehydrated. It took a while to make the correlation, but its surely there. See if you notice your hydration levels by the moisture in your eyes, mouth or nose. I notice my eyes being a bit drier than usual, and/or my saliva being thicker than usual. The 'spider-web spit' is a sure sign for me that I am under hydrated.

I too am completely dependent upon my peg. Sports drinks often have loads of potasium (and lots of electrolytes) in them if you ever need a quick fix. Tom