Hmm, but I think gender is an indirect effect on this type of opinion. Let me explain.
See, I think that when we are attracted to one gender or the other (not bi) our perspective on what's hot and not can have an double standard, at least in terms of our initial gut reaction. So, as an example, that rangrz will put his dignity and respect on the line to make (because I'm going to use some more unusual and more fetishy examples to illustrate my point) So, I'm a straight male, and I find the idea of, say, giving a guy's a hairy asshole a tonguing, pulling his sneakers off and sucking on his toes, or kneeling down and opening my mouth up so he can aim his cock at my mouth and piss into it rather revolting. More generally, I find men's assholes, feet and cocks and piss gross. On the other hand, I get the hugest boner ever from rimming a girl, kissing her toes and find drinking her pee to very erotic in the right context (usually a scene where I'm subbing). More generally, I think girl's assholes, feet and vagoo's and pee to quite nice and attractive things.
Perhaps Pagey's feelings towards men who are working out, or working hard, are different than they are towards women? If not, well you're also right roughjack, that people are conditioned to like and dislike certain things too, but I think my factor is also important to keep in mind.
Addendum: I've even noticed it with bi people, that the same act or feature is hot or not with different genders. From my own exp, like I've known bi girls who where Domme with men but sub or switch with girls, ones who had the exact same things I used in my example (i.e. who liked rimming other girls, or had a foot fetish towards other girls, but not towards guys...usually citing the relative attractiveness of those specific body parts on guys vs girls) etc. I think it has something to do with gender, but not quite in the way that pontifex01 laid out.
Edit:elle oh elle, pagey replied and confirmed my hypothesis while I was typing it out. Score me on making a working hypothesis tho, I can apparently kick it not only at physics, and not only at biomedicine, but at psychology too.