I spar with guys all the time, well, I used to, b4 my ankle injury.

I used to tell them to come strait at me and not hold back, and try to knock my head off, they've weighed as high at 250 even higher I believe, but I kick their a**es all the time, last time I sparred with a guy, it was my brother, and I beat him up in front of his girlfriend, he got so mad because I was also taunting him, and he actually taged me with a right hand, I just put that serious look on my face, and just threw a 7 punch combo starting with the left hook, switched and threw 7 more from the southpaw stance, and tagged him to the body which stunned him, and then upstairs to the head, and he threw off the helmet and walked out of the ring, and said "no thanks."

That was fun I also told his "girlfriend" i'd do worse to her if she broke his heart >