Actually.... now that I think about it, there IS a myth of the ideal man; the Muscular Man. The Macho-Man stereotype. The Body-Builder. The Arnold Schwarzenegger.
Except compared to women we [guys] have less emphasis on looks and it is hard to build muscles like that (so it's understandable if one doesn't completely live up to this image), therefore there's less pressure. (My theory)
But still, more muscles = more manly;
More physical strenght = more manly.
Then again, even as a guy I wouldn't want to look like Arnie, even if I do exercise and I want some muscles. Too much muscles means too much maintenance. Plus people might treat me differently. I might get pigeonholed into the "All Muscles No Brains" stereotype, or the Macho-Man Stereotype. (Or maybe I unconsciously don't wanna look like Arnie because I'm a cd? Okey, time to turn my brain off...)