Many thanks - yes, I realise that martial arts training can be pretty gruelling, it's just that I know my body isn't as tough as it was when I was 20 and I don't want to push it too hard in the wrong directions. But I'm interested in a martial art that concentrates more on swiftness and control that on hardness, if that makes sense. Good advice about going to chat to a martial arts instructor, I will. Again, thanks for your interest.