Why does Juan Diaz, Peterson brothers make sound effects when they punch?

I think they make thoses sounds to control the air intake in bodys.:good

 

90% of karate classes and the like are taught to youth (as most lack the tenacity and patience to stick with it when they grow up, and few adults are willing to take time in their schedule to start it up). So basically, you've outlined here in your post a very valid point that this behavior is found (and sometimes even encouraged) mainly in youngsters and novices. So not having learned to minimize that is something that's a little amateurish for guys on the Petersons' or Diaz's level to still be doing.

 

It is something that originated in martial arts, and eventually made its way into boxing. It is supposed to add force to the punch, take down move, whatever... I have no idea whether or not it is valid.

 

:deal

 

ITs like a karate " Kiyah "

 

Bingo, I was told the same thing when I was taking Kali Escrima.

 

I think the sound could somehow scare the other fighter..

 

As Ding mentioned earlier, it can be helpful in breath control. I also find it to be a mental trigger for me when targeting a specific punch. I don't verbalize every punch but when I'm sitting on one in particular I usually let out a "BOP!" when I throw it. Could also be me reverting to old martial arts training.