Does anyone get them? I will get one in my calve once in awhile when I'm sleeping. I just had one the other night. I know they can be caused by a lack of potassium. They hurt sooooooooo bad and when I get one it has to go away on it's own. Rubbing or stretching my calve doesn't help. Then my calve will be sore for almost a week. Anyone have any tips to get through these horrible cramps.