VENICE, Calif. — Remember the episode of “Seinfeld” that features Elaine trying to return a dress to Barneys after she takes it home and realizes that it doesn’t look nearly as good as it did when she was at the store, surrounded by mirrors that made her appear skinnier?

Well, it’s the opposite at Gold’s Gym in Venice, Calif., the longtime bodybuilding mecca frequented by Arnold Schwarzenegger and three subsequent generations of herculean he-men.

Here, lifters get stretched out horizontally not just by pushing heavy weights and ingesting supplements of varying legal statuses, but also through their own reflections on the walls.

And for those with a real interest in getting huge and $225 an hour to burn, one trainer stands at the front of the pack.