Martial arts is a great way to deal with stress and fitness at the same time. It is also a great way to learn patience and discipline. While it is easy to look at them in terms of self-defense, there is so much more to the training than that, and a student can learn so much more. However, for those looking for a great way to get fit and enjoy themselves doing it, this is as about as good as it gets for someone just looking for something different.
While there have been attempts to take the basics and create a pure exercise from them, these attempts usually end in failure. Tai chi is one of the few times that it has succeeded, and that is because it emphasizes the philosophy as well as the exercise; one cannot take the philosophy and render it down to pure exercise without losing a lot of the spirit of the art in question. When people look into the martial arts, they look at the entire ball of wax; the need the philosophy as well as the other benefits because they are looking to fix some aspect of their lives.
Some of those are looking to take charge of their lives, and seeking independence that they have earned for themselves. The self-defense aspect itself is well worth it, and not necessarily because the person is able to defend themselves, but because they do not need to have someone fight for them. For some that is enough and is empowering by itself, and well worth the price of admission in and of itself. Combined with the competition it provides and it provides a lot of fulfillment for them as they learn that they can be independent of others.
Others are looking for other reasons, and the whole philosophy appeals to them. People need some sort of focus in their lives, and sometimes martial arts provides that focus. By learning an entirely differently way of thought, which is required of a student of the martial arts, the person learns to refocus their lives and how some of their old ways were getting in the way of their success. Some learn entirely different ways of thinking, which helps them to find more effective ways of dealing with life. For so many martial arts are worth the experience.
Interestingly, martial arts can help those looking for new ways to become fit. The new perspective gives one a better path to fitness. Not only does it mean that the person is better able to focus on fitness as both a matter of physical exercise as well as dedicate themselves to being the best that they can be. As such martial arts is more than a mere philosophy and can easily become a better path on a number of levels for the person involved. If you are looking solely for an exercise then you are likely to find so much more, and for some people that is exactly what they need.