I know there are many different causes of leg cramps, and those causes will have different treatments. Throughout my life I've had occasional episodes of massive cramps where I'd wake up in the middle of the night in total agony with massive charlie horses and had to jump out of bed and try to stretch out of it and make it stop. It doesn't happen all the time, or even very often, but it's happened at various points at least as early as 17 years old in Army basic training, all the way through till a few months ago (I'm 48 now) when it happened while sleeping in a tent with my unit after a long, hot day of land navigation training in some mountainous terrain. That night was agony btw; kept waking up with twinges, spasms, full-on charlie horses, etc. Barely slept that whole night.

What I finally learned, when I was 41 and at an army school where I had these cramps rear up again, is that for me personally it was related to insufficient potassium. I've since bought potassium supplements, and when I am doing a lot of exercise and sweating a lot I make sure to take a few each day. When I'm doing that the cramps never occur. When I taper off and forget, and then do some hard, sweaty exercise again and blow through those electrolytes, it sometimes happens. When this happened a few months ago I took a vehicle and drove into the nearest town and bought some potassium supplements, a multi-vitamin with magnesium and everything else (Centrum Silver of course for this old man), some calcium, etc. I was desperate not to repeat the cramping of the night before. We did even harder stuff the next day, sweating so much I probably drank a couple gallons of water, but didn't have a repeat of the cramps. I can't prove that taking the mineral supplements prevented it, but I believe they did.

Again, there are various causes for cramps, and some may be related to potassium, and some may be related to other things that require different prevention measures. For me, it's the potassium.