The last week I've been cramping up on the treadmill/eliptical/etc. And this hasn't been the first time I've been working out on these machines- I've been doing it for close to 2 years. This is just outta nowhere that this keeps happening. I drink plenty of water, take a multi, stretch, and take all the precautionary measures, yet I still tence up. Anyone else take it for the said reasons or for something else?