
If a fighter gets enraged he or she loses almost each time when fighting a similar adversary in matter of speed and power. A martial art practiced well and for a long period of time learns your pretty good that a clear mind or a very clear mond is better than a stronger body. I know what the hell I am writing and saying because I have been practicing kendo (a Japanese full contact martial art). When we practice kendo (Japanese fencing) we do fight for real. We have armours and traininh swords for not hurting each other but we do fight for real.
Being emotional and toughtful when you fight may help you on your power / strenght but it only disturbs you. To keep a clear mind forget about yout thougths and emotions during training and watch out only what's in front of you or near your (that's it).