You know it is funny, I have gone to the gym many times and have only had a few reactions to getting sort of erect in the shower, and that is usually after a very intense workout.
Some times guys go into the shower area and just linger around, that does nothing for me whatsoever....and those are mostly the guys that don't work out, head straight for the sauna or showers, and you can catch them playing with themselves occasionaly if you pay them any attention at all. That sicks me out !!! Go to a adult movie theatre or something if you want that sort of action.
I go to the gym to work out mainly for fitness and some times stress release. I am not there to pick anyone up. I have made some friends there as well who sometimes give me advice, help me improve my technique, and I have received appraissal as well from them on my progress. My few "reactions" occured after a strong work out and my endorphins were high. I was chatting with a friend of mine and I noticed he was getting there too so it just happened. We didn't make a big deal about it, we continued to chat and shower. Another time it just Popped up. No reason, it just happened. Most of the time I am flaccid, not because I didn't work out enough, but it just hangs there. I do admire the many physiques I have seen at the gym, I have a very ectomorphic metabolism, so I am far from Bodybuilder type, but it some times gives me the extra push to work harder.
Just my 2 cents worth... like to hear from other guys as well. Hit me up some time if you want.