I go to the gym quite a bit myself and my belief is that body-building, for some of the guys I go with, is more than just "for chicks".Yes, there are some who do it for attention from the ladies but others seem to do it for professional reasons.
Some of these guys will stand stark naked, looking in the mirror and showing each other which parts they think they should work more on.
Other people may interpret such an atmosphere as homeo-erotic and I guess that is why guys feel uncomfortable looking at another guy's bod and saying "man, you look good" without being thought of as gay.
I usually associate the following positions to body-building.
Sun, Moon, Asc and Mars in Taurus.
Lots of perseverance
Sun, Moon, Asc and Mars in Aries.
Competitive spirits.
Sun, Moon, Asc and Mars in Leo.
Strong will to be their best.
Sun, Moon, Asc and Mars in Scorpio.
Preoccupation to "alter" oneself.
Sun, Moon, Asc and Mars in Capricorn
Motivation to be admired by others.
The oppositions, Squares and conjuctions are also relevant.
Sun-Mars
Moon-Mars
Venus-Pluto
Moon-Pluto
Mars-Pluto
Venus-Saturn
Saturn-Pluto
Saturn-Mars
Saturn-Moon
Saturn-Sun
Jupiter-Saturn