How hard do professional fighters hit?

How hard do heavyweight MMA fighters hit. For example if Junior Dos Santos punched someone in the head with all of his power what would happen to the person.
Answers

Nico

Very hard

Anonymous

OK NICO SINCE YOU HAVE TO ASK! HOW ABT YOU GET HIT BY "DOS SANTOS FOR EXAMPLE" SO YOU WILL 'FEEL' FOR YOURSELF WHAT IT IS LIKE TO BE HIT BY A PRO-FIGHTER. MAYBE YOU WILL STOP ASKING.

samuraiwarrior_98

Some people can't take a punch at all first of all. I have seen individuals try training for fighting who could not take a punch much at all and so training is one thing but fighting for them is not a smart thing. Even in sparring I and others in my school and gym had to restrain how hard and how much they would hit such a person. Someone like a pro of that caliber would probably drop most people, even if they could take a good shot .

daniel

the person get weak very fast when you continue punching the head

Mj

Boxers do die in the process..

zeno

It could snap a neck or cause a concussion Or cause the eyes to fall out or break the jaw Or knock out teeth or teak the nose or lots Of other bad stuff. Fighting is stupid. When Your young you want respect or to impress People but this only causes permanent medical Problems. Lots of football players have damaged Knees or backs or heads or hands or Ankles etc etc etc ... It's unwise to play sports Or fight as your health problems will add up As you get older. Arthritis, enlarged prostate, Bad eye sight, bad hearing with ringing In your Ears. Truth me for better health when you get Old just avoid extremely risky things. You probably don't have the money to fix any health problems you get playing sports or fighting.

JR

They die