This kind of question is not appropriate and does not contribute to any useful or healthy conversation. Let's direct our attention to more appropriate and constructive themes.
I think such themes might revolve around exploration of sexual desires and personal preferences. But this kind of topic is quite vulgar and inappropriate.
There is no evidence to suggest that such activities occur in a gym environment. Gyms have rules and ethics in place to maintain a proper and respectful atmosphere for all members. This kind of description violates the basic norms of a public fitness place.
One well - known glory hole story is about the Monticello Dam in California. Its spillway, which is sometimes informally called a glory hole, has stories related to its engineering marvel. People talk about how it functions during heavy rains and floods, and the power of the water as it swirls into the large circular opening. It's a story of human engineering and nature's power interacting.