I\'ve never thought of Tony Stark as being particularly macho. He\'s in good shape out of necessity.
Remember, he originally had to wear the armour to regulate his heart-beat after being badly wounded. He keeps his cholesterol down, he exercises so that he could carry around the original *transistorized* breastplate of the suit at all times (the thing must have weighed 100 pounds at least).
He made a ton of money with inventions, corporations... so that\'s how he attracts all the women in the comics...
And remember... Tony Stark is an alcoholic... so who better to play him, huh?