self defense AND self improvment?

The going thinking seems to be that you can train in some MA for the sake of self improvement OR train in something that would actually work in a fight.

There must be some MA out there that has benefits of a traditional art while actually preventing you from getting your ass handed to you if you ever got in a real fight.

I'm thinking it likely comes down to the instructor more than any given style, but I'll admit I don't really know.