On the other side, it shouldn't be assumed that because one practices one of the traditional internal arts that they know nothing about fighting. Most of the internal instructors I've learned from came to the arts after long and distinguished careers in either full contact tournament fighting, the military, or some heavy streetfighting days and were looking for the specific benefits offered by the arts (and they can teach all of that within the internal styles.) The need to correct the damage from those years has been a big part of the rationale for people who crossover to concentrate on internal work later on. There is a big enough difference in body mechanics and theory emphasis between internal and external forms that it may be more beneficial to focus on one or the other, but that isn't necessarily the case - even younger fighters may find training in an internal style brings other benefits. But we've also got instructors now who have trained under purely internal mentorship who have what that the original instructors have without having to take on that kind of damage...it's really a matter of the quality of training and the other forms of testing and conditioning that are involved.
It's up to each person to do a realistic assessment of what they need, and what best gets them there. In my plus-four decades of life, I have not been in a situation where I needed to physically fight since my teens ('nuff said), even with spending many years getting myself home through big bad cities alone on the evil side of midnight. My one experience with an armed mugging did not demand any physical combat response - I was prepared for it (carrying easily replaceable currency), was able to stay calm and assess the environment and options in a nano-second thanks to my instructor's training, and was able to verbally command the situation to survive it rather than escalate it. I do keep the self-defense weapons sharp just in case - as the Inosanto salute says, "With my mind and heart, I cherish the knowledge my instructors have given me. For it is my life in combat."
But the reality is that the biggest threat to my life comes from within, and I have to battle it daily. Depression, anxiety, bad stress-coping patterns that can damage my health - those are my usual adversaries, sustained from a lifetime of living in an environment of combat that was rarely physical, but just as damaging, as neuroscience is rapidly showing. And the benefits I've found from the internal arts have been the best training for meeting that threat. Not to mention that Father Time is starting to really hammer me, and training helps to slow that process down.
But, going back to the original emphasis of the thread...I do have to stress that these benefits are really dependent on the quality of the instructor and their personal development with the arts. It's far more than just learning a pattern of movement or the "steps" of a form, and if your instructor is not internal themselves, they won't be able to see or guide your progress in them. There's a longer learning slope to internal arts - where one can get really good in combat styles quickly (a necessity for creating battle-ready troops, historically), the internal development starts very slowly, takes many years to rebuild the body connections - in essence un-learning all the established patterns of tension - and then has a steep gain.
And there's a big need for being careful in believing claims at face value - this is a market, and an industry, and no one gives their competitive advantages away for nothing when everyone you train is a potential competitor. Instructors know that people will be mostly happy to learn a few moves, get some exercise or therapeutic gain out of it, and will not have the dedication to truly master the arts at the level where the benefits really show themselves, so they often reserve their full teaching for students who prove they are going to be worth it. These arts have a long history of secrecy, (even within a school, frankly), and there's a lot of issues that determine who gets the "real thing"...and an unethical teacher in the internal arts can damage you in ways far more serious than a broken bone. So be aware, and if you do get interested in training in them, do some background reading and really observe the teacher and their senior students. If they have it, the difference is unmistakable. The big problem is that unless you've experienced what "it" is, it's hard to know what to look for, and that's how a lot get away with overblown claims.
