Here's a very interesting story from the NY Times today on muscle
cramps - that come from running, swimming, cycling, or even sleeping
(the worst!). It says there are no definitive studies that can really pinpoint the cause of cramping, but mentions the usual suspects - exercise, fatigue, dehydration, electrolytes, potassium, and stretching.....

The article is called
A Long-Running Mystery, the Common Cramp

and can be found here

http://www.nytimes.com/2008/02/14/he...syahoo&emc=rss