In The Power of an Emotionally Charged Theatrical Fight, an article on Backstage.com, Tim Weske says:
[A fight] is a huge moment in the life of a character,” he explains. “He’s facing life and death, and when you’re angry enough or insane enough to pick up a weapon that you’re going to hurt somebody or kill somebody with, you hit one of the highest points of human emotion.
It’s important to remember that fight choreography isn’t just a process of determining an order for attack and defense while imitating some historical style. Your character is fighting for a reason.
When was the last time you threw a punch in anger? It happens so rarely in our society that it can be hard to connect with that level of aggression. If you play a murderer on stage, whether part of an army, or a scene of desperate self-defense, you’d better bring the emotion with it.