Arnold goes undercover at Gold’s Gym for charity

Some unsuspecting Gold’s Gym members in Venice, Calif., got the workout of their lives, when Arnold Schwarzenegger showed up to offer some unsolicited help.

Donning a mustache, ponytail wig and the name “Howard” on his Gold’s Gym uniform, the bodybuilding actor pretended to be a fitness instructor and regional manager at the gym.

While “Howard” tells one laughing woman to take her work out seriously, Schwarzenegger demonstrates some major comedy chops.

He even makes some poor girl at a water fountain do 10 “reps” of water, because hydration is important.

The former California governor went undercover to raise money for After-School All-Stars, a charity that supports year-round education- and fitness-based after-school programs.

Schwarzenegger is also offering a contest to benefit the organization. For a minimum of a $10 donation, you are entered to win a chance to fly out to Los Angeles and spend a day with the actor, including a workout and riding in his personal Sherman tank.

(In case you think you didn’t read that properly, you did. Arnold Schwarzenegger has his own tank.)