I'm too muscular to smile

Going to the gym is a bizarre experience. On the one hand, I love that feeling of accomplishment (aka achy muscles) at the end of a workout. It's also nice to feel like you're doing something good for your body (and for looking even better too). However, the people at any gym always seem to have a serious look. Most men tend to walk around their arms spread out like they're carrying invisible purses underneath their armpits. They also have this serious constipated look the majority of the time, especially if they're working out alone. The women don't look too happy either, and seem to love the stair/climb master machines and anything cardio related. They don't tend to smile too much either, but it's probably a good idea because the muscle heads like to gawk at them as they walk by. I'm sure a smile would be misinterpreted by muscle men as a signal to 'hey come over and flirt with me'.
Yesterday at the gym, this cougar lady who keeps smiling at me since I started working out in 2003 spotted me again! It's kinda creepy, but it's not a big deal, I suppose I can take it as a compliment about the way I look.

Update: today at the gym I saw a man perfectly exemplifying what I wrote! Except he was walking around with invisible duffel bags underneath his armpits, not purses. He was walking on the treadmill with the most serious face known to man - almost a zoolander like look of determination, and he would wave his arm stiffly in an ape-like fashion. Honestly, who walks around like that?!