You might be low in magnesium. But it might be you just stressed your muscles more than usual. https://www.healthline.com/nutrition/magnesium-deficiency-symptoms#section1
It might be a good idea to get a complete blood profile to find out if you are lacking anything in your diet, if you are going to do stuff like mma.
It's extremely common the farther South you get. Where I live, it's mostly short shorts, and skin tight denim. But farther down south, towards South Carolina, Georgia, Alabama and Tennessee, it's commonplace.
Wish me luck, and a prayer or two. I spotted a super rare bottle on ebay for really cheap, and me and about three other guys noticed it. It will be a bidding war, but even if I pay $100, the profit of re-selling it will be worth it.