Depends on the martial art: head injuries would complicate that analysis; tai chi isn't terribly aerobic, etc.
Also, to be contrary old dude into martial arts all his life, I don't really consider many head bashing 'styles' now to be 'arts'. Martial, sure.
Which ones would you consider to be "arts", and worth getting into?
I was recently thinking that I would like to get back into martial arts, but having done taekwondo in the past, I'm absolutely not interested in going back to any form of bashing impact..
Anyway; as a kid I did Judo and after that Kyokushinkai and Jiujitsu 3-4 hours a day for many years.
I am 50 now and I can do things many 50 year olds cannot do, but the joy for me is that I feel like when I go to aikido class 3 times a week, it is an art and it doesn't feel like I have to ever stop doing it as I don't need (but can I guess) to bash in faces in a rings.
I really wanted to try Aikido, and went as far as doing an introductory class at university. Everything was fine until the next morning when I couldn't bend my elbow anymore, with an over strain pain that lasted more than a week. I was quite in shape at the time, so I took it as a sign that maybe it wasn't for me. (Or at least not in that school..) And that stopped me in my tracks unfortunately.
But I'll keep your feedback in the back of my head, and let's see what the future brings.
Im not a great boxer or anything but I used to do melbourne shuffle a lot and it definitely has the same vibe to me