I have severe leg cramps almost nightly, even if I take 3 or4 days off riding. I have tried all of the above mentioned supplements, switched to a waist mounted camelbak to be sure I was well hydrated, experimented with quinine, all to no avail. I get up and stretch only to have a different set of muscles cramp. Often it is not even the opposing set of muscles. Sometimes I suspect it is triggered by lying on my side too long; but we have a Tempurpedic mattress, so I don't really think that is the case. I have spoken to my primary care doc, she has no more suggestions. I'm currently managing them by a quick stretch to get out of the screaming stage, then walk to the bathroom (stepping over large dog) and back. That short walk seems to work better than more stretching. When I get back in bed I try to get into bed with the non-affected leg as relaxed as I can keep it. And my husband wonders why I have trouble getting up in the morning.