The practice of the martial arts requires more than just physical discipline.  At its best, it entails an affective, intellectual, and moral discipline, as well.

NEWS FLASH!! The Nikkei Games are held in the Pyramid on the CSULB campus every August. This is a big national event.  The games include competitions in karate, taiko (traditional drumming), naginata (a long weapon with a blade at the end), judo, iaido (sword), sumo and kendo. http://www.seyo.org/nikkei.html

Take a look at the Journal of Asian Martial Arts.

I first studied martial arts some decades ago under the great Shotokan master Takayuki Kubota.

I have also studied Ryobu Kai, which is very similar to Shotokan,

and Koei Kan, a traditional Japanese form of full contact karate.

These days, I study and teach Shaolin Chuan Fa, the martial arts of the ancient Shaolin Temple in China.

If you are interested in studying a modern hand to hand combat system, rather than a martial art, I suggest Krav Maga, the martial system of the Israeli Defense Forces.  Some of us at my main dojo have been exploring this recently -- "Krav maga" means "contact combat" in Hebrew.  It can be learned more quickly than a martial art (months rather than years of training are required), though the learning is not as deep, nor does it affect the whole person as does a martial art.