Then there's Mr Hey Look at Me - he wears a bright yellow t-shirt, and does things like pedal really slowly on the bike for a while then suddenly go like the hounds of hell were after him. Then he'll go slow again and sit up and look around to see if anyone noticed him. He does this on all the aerobic equipment in turn and I struggle not to laugh as he does it on the treadmill. See, he doesn't change the speed the treadmill is going, he just grabs the railing bit and hammers his feet up and down at twice the speed the floor is going.
And then there's the Sadomasochistic Pair. Two chaps, one of whom clearly works out a lot (the sadist), and one of whom is just starting (the masochist). The first one is 'training' the latter, but what that seems to consist of is the sadist doing umpteen press-ups/whatever exercise and telling the other guy to do them too, then when the masochist can't do as many press-ups/whatever as the sadist he gets abuse hurled at him for not trying, or gets told to "Just shut up and fucking do them". And this repeats for at least half an hour, with, obviously, the masochist getting tireder and less able to do 20 press-ups in a go and the sadist getting louder and more abusive. If it were me, I'd tell the sadist to fuck off and then not come back. But the masochist is clearly enjoying the abuse.
The rest of us are normal. No, really ;)