Yes.
It's called consideration.
This thread is a microcosm of something that ails America today: the self-referential focus on self, and the rights of self.
There are concepts on the other side of the coin, like duties, responsibilities...and consideration, which is perhaps the most honorable of all because it is often something you need to actively think about, not something for which there is an easy accepted standard to which to adhere. To be considerate, you have to take your head out of your a-hole...which for many, is proving to be increasingly impossible.
For whatever reason, the young don't like to have older people around in certain situations--and whether you think their reasoning is "good" or not doesn't matter. Put yourself aside for a second, and think from their perspective. Sometimes when you don't agree with the thinking behind something, or even if you don't understand it and think it makes no sense, you should be considerate, because the fault may be your own for not being able to see the entirety of the situation.
It's analogous to the situation presented in that old saying "What is more important, understanding or compassion?"
Not all younger people in the college gym will dislike your being there, but I would bet that a fair proportion will. I remember people talking to me about it when I was in college, which is why I chose at all to write in this thread.
Regarding age discrimination...think back to when you were young, when did you invite your grandparents or any other older person, even say a 40-year-old or even 30-year-old, out to a rock concert? To do a 20-miler? To go on a pub crawl? To go out and get shxtfaced at homecoming? To do a cross-country roadtrip? Etc. The answer is never. You were discriminating based on age. You did it all the time, without even knowing it. It's called being young.
And I speak from the perspective of a guy who can still hold his own in a real gym, unlike 99+% of older posters here, and I'm not yet old enough to be droopy or gassy. I speak also from the perspective of a guy who does some coaching of collegians, and who has gone into a college gym in a coach/trainer capacity.
Leave the kids alone. Yes you may have the right to go to the gym, but you should have the class not to.
Of course not all college gyms may be the same. I know one private college gym out east that seems to be mostly community members, in a small college town. Even the outdoor track is loaded with geriatrics walking around, and the college doesn't care because they are benefactors, alumni (future benefactors), etc. Total PITA and buzzkill even for me, someone who can still work out hard on the track.