Flex your foot to avoid charley horses

Saw this tip in a random reddit thread. Several times I have woken up stretched my leg and gotten the worst pain in my calf aka a charley horse. When you stretch your legs in bed DO NOT point your toe down, that is the road to pain. Instead you need to flex your foot up towards you. This has me avoiding charley horses since learning (except for the one time I forgot). Also more electrolytes probably.