Cramps! (the muscle kind)

starkspot

Most Americans don’t get nearly enough potassium. There are lots of other foods in addition to bananas with potassium. I eat LOTS of spinach.

https://www.healthline.com/nutrition/foods-loaded-with-potassium#section2

rheddmobile

You're getting good advice on the tonic water, bananas, etc. just wanted to add that for me at least, grasping my toes and pulling them together or sometimes pressing on the bottom of my foot will stop a calf cramp, especially if it's the kind you get from pointing your toes.