In a viral YouTube video, the former Mr. Universe poses as a personal trainer named "Harold Kleiner" at Gold’s Gym in Venice, California. He shocks unsuspecting gym members by asking them about their workout regimens and dabbing their sweaty foreheads with a towel.

The stunt was done to support After-School All-Stars, a non-profit organization that encourages childhood fitness. As of Wednesday evening, the video had racked up 2.5 million views.