Watch Arnold Schwarzenegger Working in Disguise at Gold's Gym

"Stop being a baby!" he yells at a member.

Jan. 22, 2014 — -- "I wanted to have a little fun and raise money for a good cause, so I went to Gold's Gym in Venice in disguise," Arnold Schwarzenegger said in a YouTube post.

A hilarious video shows the action star and former bodybuilder pretending to be Howard, a physical fitness instructor who has become a regional manager at the gym.

The disguise and effort were done to raise money for after-school programs.

Schwarzenegger wears a mustache and wig, and a black polo tucked into a pair of khakis. He instructs members on how to get in shape and stands by the water fountain telling people it's important to drink lots of water.

"You look familiar to me," one gym member said.

"Stop being a baby! This is Gold's Gym, this is not a baby gym," the actor yells at one member.

The video is a must watch and will have you laughing out loud.