One common theory is a magnesium deficiency. Can try supplementing with a mg/calcium supplement for a few weeks. The mag plus calcium automatically come combined in same pill because need calcium to make mag available to your cells. Also, remain well hydrated but dont want to overdo plain water. Need your electrolytes replenished if you sweat a lot in the heat or exercise regularly. Watermelon (the real thing) is great for post workout replenishment.