I always wear sweats and a loose fitting sweatshirt. In the summer when it gets hot in there I'll switch from sweatshirts to long sleeve t-shirts. I've never been much of a show off but at the ripe young age of 40 I still look better than most of the twenty-somethings that come in there. Doesn't matter though...I'm not there to socialize or hit up the women. I go early so the crowd isn't usually too heavy and on the rare occasion that I do go late it's still not a social occasion. I go to work out and get the hell out of there.
Sooo....to answer your question I'm also missing the vanity gene.