This article speaks for itself, but this is absolutely my favorite passage:

Turner says he’d prefer to hire a trainer who has a four-year degree in physical education or kinesiology, which is the study of body movements. “I’d rather have a trainer with a college degree and no certification than the other way around where they come to me with bad habits,” he said. “I’ve had trainers come in with all sorts of certifications who couldn’t name four muscles in your back,” he said.

At the end of the day, you truly do get what you pay for.

MarketWatch: 10 things personal trainers won’t tell you.