Confession time!
I did (age 15, for all the difference that makes) send off for the Muscle Dynamics programme.
Can't remember if it was the Gateshead chapter or the Isle of Man chapter, although presumably they're the same thing.
I got a very lo-fi book back in the post, which, believe it or not, was relatively practical. It listed a number of exercises you can do in your room without needing any weights or equipment, essentially using your own body as the weight to lift. Of course paying for a book to tell you to do press-ups and sit-ups isn't exactly ground-breaking stuff. It also suggested eating well would help. But it didn't encourage me to send off more money for weights and/or protein shakes.
More salubrious were two appendices: the first telling you how to astound your friends with feats of strength. The only ones I recall were precutting the pages of a telephone directory, thus enabling you to rip it in half at an opportune moment, and a technique for exploding a hot water bottle through the power of breath that made no sense. Blow real hard! was the essence...
Appendix 2 was 'how to be a super-stud'. Charmingly, the advice was practical and simple - be confident, and be prepared to ask lots of people out, 'cos you WILL get rejected more often than not. If you do strike up conversation, actually listen to what the person is saying. It didn't mention 'bring up comics in conversation,' mind.
Needless to say, while I did follow the exercise routine for something like 3 weeks, I did not build any muscles, achieve fabulous feats of strength, or have any more luck with girls.
On the plus side, John Smith gave me Stanley from Slaughterbowl as a role model to aspire to at around this time, clearly the better man than the meathead with the bigger dinosaur.