On the gym floor, guys are eye-fucking each other all the time. As I'm doing squats, a guy will stand directly behind me admiring the view. If you're into him, you just look back and flash him a smile. Then they keep an eye on you as you complete your routine. When you start heading up the stairs to level 2 where the lockers are, they follow and hunt you down.
There are guys at City Gym who skip the gym and head straight to the locker and stay in there all day. Or they'll sit on the benches outside the locker and watch guys going in and follow.
I actually really like this venue more than official sex-on-premises clubs or bathhouses because the guys are all roided up and horny and ready to play but it's a legit gym with awesome equipment for real weightlifting. People can come here to make real gains and everyone respects that, and sex is secondary. You can absolutely come in and get in a nice workout and leave untouched and unbothered given that you follow basic cruising etiquette (basically don't look at someone if you're not vibing with them. Once you lock eyes, the hunt begins...so be careful where you look). And avoid the sauna if you absolutely don't want to have sex because that room is much more sexually charged and sex forward.