Weight drained usually occurs in fighters struggling to make weight.

Fighters who struggel to make weight usually attempt to dehydrate themselves and shed any retained water in the last few days before a fight.

The membrane inside the cranium, thats serves as a shock pad, is composed of a very high percentage of water. When the body's water percentage decreases so does this mebrane. With the membrane depleted, the brains shock absorption capabilities are diminished.



Some of the guys that drink may understand this. Alcohol too causes the body to dehydrate. This causes headaches the morning after.
I magine getting hit in the head in this state.

Now imagine you are dehydrated for days before a fight with another professiobal athlete looking to hurt you.