Some fitness centers specialize in certain types of training, such as plyometrics, Pilates or TRX, for example. If you don’t already know that style of training, show that you’re willing to learn. As a certified trainer, you need to complete a certain number of continuing education credits to keep your credential. So if you don’t already know that style of training the employer mentioned, tell her that you’re going to pursue training for it during an upcoming continuing education seminar. If you already know that style of training, tell the employer about how you’ve used it and what successes you’ve had in using it with clients.