When I was a kid, we'd all look forward to Friday evenings - because Dad & Grandma would come back from town with the weekly supply of comics. The ads in the back were almost as good as the cartoons, although we were very disappointed to find out that sea monkeys were definitely not as advertised! I also remember regular ads featuring a poor weedy guy who, having had sand kicked in his face by various over-muscled bullies, followed the instructions of various manly authorities and ended up developing his own set of biceps, triceps, washboard abs & all the rest: all the better to impress the girls at the beach.
I was reminded of all this earlier this week when I noticed a Facebook report on bicep-flexing in male kangaroos, based on this 2013 paper in the Biological Journal of the Linnaean Society. (It's behind a paywall, alas, but you should be able to read the abstract.)