Hissing breath: striking fear with your punch

Hissing breath

Exhaling with a hiss. This is a Muay Thai tactic. You exhale air this way, keeping you cool. An advanced fighter however uses this as a training challenge:how many punches can you draw in one hiss.
As you punch make this hissing sound. It throws the air out of the stomach. And keeps you cool. Also strikes fear in your opponent.