A gym where Comic-Con is the reigning spirit

Los Angeles

THE first sign of what is to come at Nerdstrong Gym in North Hollywood is the red welcome mat: It's in the shape of a Dungeons & Dragons 10-sided die.

The equipment inside includes 11kg steel clubs (for the potions class portion of a Harry Potter workout, among others). A concrete wall is painted with pixelated Space Invaders from the 1970s video game. And the gym's handbook reassures members that workouts can be scaled from Padawan to Jedi Master (that's Star Wars for "pretty easy" to "really hard").

Since this gym opened in 2013, members have kicked down dungeon doors, defeated the Death Star and raided ancient temples with Indiana Jones.

An Eye of Sauron workout, drawn from The Lord of the Rings, features step-ups (Frodo and Sam had to climb a lot of stairs) and sandbags (evoking Sam carrying Frodo up Mount Doom). Every three minutes, when the Eye of Sauron sweeps across the gym, everyone has to …