any time I hear anything about cramps, spasm, tics, tightness, and so on I go to magnesium status first. particularly against the backdrop of strenuous exercise. consistent with your hypokalemic history as well. a serum magnesium result could be very telling. easy to get.
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com