I saw someone mention on the internal arts board that part of his training was cardio-style conditioning that allowing him to take more hits and keep fighting.

Now, I understand that cardio allows you to fight longer and harder and so on, but is it in any way possible to condition your "chin"? Aside from learning what it feels like to get hit, will a lot of endurance training allow you to take hits to the head and not get dazed or KO'd or anything? The guy on the internal arts board didn't claim his training did this, but I've seen people say this in other places, that such and such was able to take all those hits to the head because of "superior conditioning" (most of these related to boxing in some way).

Is this possible?