interview at Golds Gym

What should I wear to the interview?

What type of position?
You can never over dress for an interview.  Wear a suit (with a tasteful tie.)  Bring a resume with you too.
Unless they want to see what kind of shape you are in...you could always take your clothes off for them.

titty clips.
 
nothing else.
 
 
Seriously, i would go with business casual for a gym. Normally I would say suit and tie, but a gym is a bit different.  00Accord is right...you can never overdress.

If it's warm I'd just wear a nice pair of khaki shorts and a polo shirt (that's usually dress code for a gym anyway), unless you have a gut then I'd wear a suit *L*

I would have said business casual for a gym, but I wouldn't want to get there right after some guy who just interviewed for the same job that was wearing a suit.  Then you might look like a slob.