Often times fast-talking dudes from New York or Los Angeles will phone some athletic young guy and start bedazzling him by dropping names of magazines and campaigns his models have done.
He says "Our models have appeared in Fitness RX, Men's Fitness"... blah blah blah and then slips in that "We also cast for a few adult projects".
Truth be told, it is likely that he has no fitness magazine opportunities and if he does, it is for some thinly veiled homoerotic fitness magazine which shows models doing squats in speedos. It is likely he wants you to get into jackoff videos, and there are no fitness modeling opportunities.
With the exception of Rob Sager, it is highly unlikely the fitness industry is going to book from an agency that also books porn. It takes contracts with supplement companies to earn substantial money in fitness modeling. Are these organizations going to tend to work with people in porn?
So, when a person on the phone mentions "adult productions" casually in passing. Move on. When they mention "Playgirl style projects", ask the exact name of the project. They are likely mentioning the Playgirl name to give legitimacy to their real (sketchy) endeavor.
Remember, no model release can be truly encompassing of every angle and protect you - so you must rely on the reputation of the person you are dealing with. Don't be afraif to ask for the name and email of a young guy who they have already worked with. If there relationship with that guy had no problems, there should not be a problem with supplying you their email address as a reference..