Internalized homophobia is often associated with attempting to distance oneself from things that are associated in society with being "gay," and this could include going to the gym obsessively or trying to imitate straight homophobes by sneering at "effeminate twinks." Internalized homophobia is a lot of the reason that some gay guys throw off kind of hard on transsexuals. They are trying to redirect the homophobia they have been subjected to in society that they have internalized deep within themselves.
Internalized racism can cause similar things: sometimes black people throw off on gay people, hoping that somehow, if they identify with the "white oppressor," the white oppressor will be more accepting toward them. They pick up an association between "being white" and being a bigoted jerk, and they have a weird concept that they can be "more white" and "less black" by being bigoted jerks. They don't even really quite realize they are doing this. This is not anywhere near as bad as it was a few years ago, thanks to some old guard black activists realizing it was a problem and stepping up to do something about it.
Anyway, another example of internalized homophobia is thinking of being gay in mostly negative terms. Take, for example, the behavior of engaging in anonymous unprotected sex. Because the negative stereotype of gay men is that they are all sexual hedonists (in the negative sense of the word "hedonism," not in the sober philosophical sense), the gay man who is suffering from internalized homophobia grows up with the belief that this is what "being gay" must mean.
But it's really a subject that, in academic circles, is still being studied.