This fixes it instantly every time for me. Ignore everybody else. When you get that cramp start moving your foot in the opposite direction pointing your toes towards your knee and stretch out the back of your ankle. Instant cramp relief everytime.

If you have cramping often like this then maybe dedicate yourself to some hamstring stretches.

Stand up as fast as possible and put your weight on that leg.

I only cramp when underhydrated and most people are underhydrated (Drewnowski, 2013).
Make sure we're all getting enough water before taking further action!

References
Drewnowski, A., Rehm, C.D. & Constant, F. Water and beverage consumption among adults in the United States: cross-sectional study using data from NHANES 2005–2010. BMC Public Health 13, 1068 (2013). https://doi.org/10.1186/1471-2458-13-1068

"Toes to noes!" Stretching your foot upward helps prevent it.

WE ARE CHARLIE HORSE!

magnesium prevents cramps.

You're dehydrated

You need a little Magnesium

400mg of Mg daily fixes this.

I challenge you to simply sit there and watch your toes curl. It actually stops hurting if you can just relax and let it happen.

I used to suffer from them regularly as a kid. Just drink water. Thats it, nothing magica... maybe it's the magnesium as another poster said. But honestly I have never had one since I changed my life and joined the hydro homies.

That's not just me?!? I have to IMMEDIATELY jump out of bed and stand up and rub my calf or the pain is going to intense.

Charlie's not been around for a long time... Since I tripled my magnesium bisglycinate dose (spread out through the day), along with other minerals.

I feel seen.

Yeah foot inner arch begins to scream out of nowhere while relaxing, happens once or twice a year since always. Skips a year sometimes. Thanks for others' advice that's been posted.

Hydrate!