Quote Originally Posted by OakLeaf View Post

Personally, if my leg cramps are any indication, I sweat out more magnesium than calcium. I find it hard to believe that the electrolytes in your sweat depend on the sport you're doing, though. I think it's just that cyclists tend to spend a lot more time at their sport than other athletes, and thus sweat out more electrolytes total.
I don't think the calcium is lost in sweat. Sweat is the end product of cellular respiration, in which calcium is not a factor.
Calcium is a factor in muscle neurons firing. "At rest, neurons contain an overall internal negative charge, called the resting potential. This potential is maintain by the Na+/K+ pump which actively pumps out 3 Na+ for every 2 K+ in"

Discuss.