She’s the woman you love to hate the most, but she’s also the one pushing you harder than anyone else toward that goal. The relationship with a personal trainer is a unique and special one, and clients either soar or break under their tutelage. For every tidbit of insight and encouragement your trainer offers you, there’s something she’s holding back.

Pamela Hernandez, a certified personal trainer and health coach, recently published a really insightful piece on her blog at ThriveFit. She is regularly faced with clients who complain, “You make it look so easy!” She usually says “Because I’ve had more practice.” What she wants to say but leaves out to those bewildered clients, “I have to make it look easy so you don’t start doubting my ability or yours.” She plans workouts in advance and tries new stuff several times on herself until she’s got it and trusts that she can properly show you. You’ll get it too…with practice!

We talked with a few trainers who keep a few things to themselves during those sweat sessions. Whether to maintain the relationship, your respect of their position, a level of professionalism, or to not insult, offend, or scare you away, these personal trainers know when to keep their mouths shut!

“I think I am going to give the high protein diet a try,” said one of Valerie Orsoni’s clients to her. A wellness expert and founder of LeBootcamp, Valerie says she knew what the outcome would be for her client, recognizing that rapid weight loss with an equal or better regain were in the cards.

“I had already told her several times not to,” recounts Valerie, who this time didn’t say a word. “I let her do it for ten days, and then we looked at the situation and she realized, had I said something at first, she might have wanted to ‘win the fight’ and might have done it on a longer period of time.”

Lauren Martin, a NESTA personal trainer, will never lie about your progress just to make you feel better. If you ask and she answers, know it’s the honest truth, even if you don’t want to hear it. She’ll also never compare you to another client. Like most trainers, Martin believes in positive reinforcement; and she’s certainly not going to downplay another client’s efforts to boost yours (or talk yours down to someone else).

“Shut up. You’re wrong,” is bubbling just under the surface for Byron E. Hall, III, a district fitness manager for Portland Sport and Spa who holds a half dozen varied national fitness certifications. He’d never tell you that you need to remember that your trainer is “untangling years of bad information and habits in order to help you work smarter not harder, and we only have a few hours a week to do so.” So listen up. You’re paying him and trainers like him good money to get their expertise. You wouldn’t second guess your cardiothoracic surgeon based on what you scraped together from a few health talk shows, so don’t second guess your trainer based on an infographic from a fitness mag site.

His other dirty secret? “We eat like [garbage], too!” Yep it’s true. He may have told you to skip the dressing-soaked Caesar, but he did it with a burger and fries on his breath. “We just know that our usual healthy eating habits and consistent workout routines will easily offset that massively calorie dense lunch, and we’re pretty sure that’s the last thing you wanna hear!,” he said.

Pamela is right there with him, owning up to enjoying homemade ice cream on her birthday![insert shock and horror!!] “A client made a comment about how on my birthday I probably celebrated with hummus and vegetables.” Yeah right! Ice cream fits in with the 80/20 rule she lives by and prescribes to her clients. “I practice what I preach because it makes me feel good.”