Some of you may remember ads like this cropping up in boys comics such as Rover, Tiger and so on, back in the 60's. They always depicted men rather than boys in them - another one for example was the body building ads for Bullworker. I think they were trying to make sure us boys grew up big and strong so we were able to defend ourselves when the occasion arose.
This one above is dated 1966 and was for a variety of books containing different courses to try out - things like Ju Jitsu, Self Defence, Karate, and a few others in that territory.
However, there are also a couple of courses in there that has got me wondering how they can help you when you are being bullied - books on Stamps and Typing?!!
Then again, I suppose if you chucked your Olivetti typewriter at your assailants noggin, it could do a bit of damage!!