A martial art’s primary purpose is to fight: to stop the attacker from injuring you and to injure or kill attacker. However, some martial arts were created as sports, such as Judo, and some have evolved into sports, such as sport Taekwondo. No matter your objective, fighting or sport, you will run into a problem when you train in more than one martial art. The martial arts clash in your thinking and in your actions causing indecision. If you train using a Karate side snap kick part of the time and then train using a Taekwondo side thrust kick (Taekwondo rejects the side snap kick and you will be chastised if you use it, when you spar or have to defend yourself, your brain and body will hesitate for a second before acting to decide on which type kick to use. This hesitation may be the difference between your living or dying. \
The organization I am a part of spars in class using hand contact to the head. In competition, they forbid hand contact to the head. So, for months you train using hand contact to the head, and then, for a few minutes four-times a year, you must spar under stressful conditions and not use hand contact to the head. Because of this clash of methods, in competitions, there are many times when students foul out because of hand contact to the head, and there is always that second of hesitation when the brain and body want to react with a head attack with the hands.