I posted on this a while ago in some detail, but the bottom line on why you are cramping is your low electrolyte levels. The calves are first to get the cramp for some reason...maybe because you're always on them. But in anycase, all the water you are taking in to keep you hydrated is washing out valuable postassium. Eat a banana, eat baked potatoes. Those are the two natural sources with the highest potassium levels. I like using a potassium-based salt like No-Salt versus table salt which is soduim-based. By the way, those cramps are a wake-up call! There's one other muscle that gets a little more use than your calves....your heart! If your electrolytes get too low, the lack of potassium WILL cause a heart attack. I'd fix this issue pretty quickly bro!