Brazilian Jiu Jitsu has been very useful to me. My cardio has improved dramatically, I am much stronger than I used to be, and I’ve gotten a lot of enjoyment out of going from absolute trash to slightly less trash over 2 years.

But I don’t expect it to really help me in a fight. If I did get into a fight, I certainly would do better than if I hadn’t trained; but one thing I’ve learned from fighting people for like 8hrs a week is that it is REALLY easy to fuck up and get hurt in ways you wouldn’t expect. The outcome of a fight is unpredictable - especially when the other person could have a weapon. The best martial art for self defense would be running.