In addition to being a great source of magnesium, magnesium malate has been very helpful in relieving my muscle ache. Magnesium malate is magnesium plus malic acid. I got the idea to use it from this web page, which mentions magnesium and malic acid to relieve fibromyalgia symptioms. There are many supplements listed here that are worth trying.

http://www.flcv.com/cfsfm.html