My ex (a one time sports therapist or athletic trainer or whatever they call themselves now) used to keep sachets of ketchup from fast food places for the players to suck down if mid game cramp struck. That and snack boxes of Sunmaid raisins.

I've had restless leg syndrome all my life. Sometimes can't stand being inside my legs. Often have the leg cramps, but now I know when it is coming. I usually have a glass of water, eat a banana or baked potato. Also stand on a step with my heels hanging off the edge and then lower my heels, stretching the calf muscles. Then do lunges which also stretches the hamstring.

Ususally nips the cramp in the bud.