Back Calf Muscle Cramp

Yesterday I got training practice on sparring...
After 2 hours during practicing, I hurt my right lower back leg...
Not very hurt but I feel that something is pumping inside there...
I guess that I had muscle cramp on that...
So I did middle split and stretch a bit more on my right leg before do the front split...
A bit relieved after that...

But this morning I went to toilet and excreting "unnecessary body waste"... haha
After a minute in squatting position, my calf was going to pump again until I felt pain in it...
So I endure a bit till I finish "throw waste & wash-up"...
I slowly stand, go wash my hands and feet, and walking to my room...
I did massage my calf a bit and rest by sitting a little while and stand up and do light jump...
After that I lie on my bed and try to sleep...

I've done internet survey about this and I found out that calf muscle cramp (known as "ular-ular di betis") is caused by:

• Strenuous exercise during day
• Overexposed to cold temperature e.g. air-conditioned room
• Pregnant women usually lack of  potassium, calcium, & magnesium during the next final months
• Health problems including peripheral arterial disease, kidney problem, thyroid problem and multiple sclerosis
• Standing / Sitting on  a hard surface for longest period or put leg in a wrong position while sleeping 
• Problem of lack of body water (Less intake of plain drinking water)
• Medicinal intake such as anti-psychotics, control pill, diuretic pill, statin or steroid.

So, I conclude that my right calf muscle cramp is caused by strenuous exercise, also wrongly positioned my leg during sleeping I guess...
Huhu