Last month, I joined a new gym. (So did my boyfriend, and we hope to work out together more often.) Each new member is offered one free session with a personal trainer.

The reason I wanted to join a gym is because although I exercise regularly--I run three times a week and practice yoga most days--I (gulp) skimp on strength training. Though I do build strength with yoga, I know I need to add some cross-training to my regimen. My excuse: I'm busy! But, by rejoining a gym, I have committed to strength training at least twice a week. So far, I've stuck with that goal.

I arrived at the gym, ready to work out. The trainer started with a fitness assessment. My body fat had dropped a half-percent since April (yay!), and my weight was about four pounds higher (I was wearing shoes, but I haven't been running as much in this heat). I felt pretty good about myself. And then we started talking…

The trainer asked me a little about my fitness background:

"Well, I haven't been to a gym since last fall…"

"Last fall?" he asked, his brow furrowing.

"Yes, but I'm a yoga instructor and I've been training for various races. Between running and yoga, I didn't need a gym. I work out at least five days a week."

Trainer wasn't pleased, but he moved on.

"Why aren’t you in the best shape of your life?" he asked.

I cleared my throat, contemplating my answer.

I am in the best shape of my life. I'm not the thinnest I've ever been, but I'm definitely the strongest. I ran a half marathon three months ago, and I'm starting to train for my second one. My shoulders and arms are getting stronger and more defined, and I just feel good.

"What's keeping you from reaching your fullest potential? What's your weakness?" he asked before I could respond.

"I like a glass of wine with dinner," I said. "I like good food. I eat right, but I eat."

"Well, it sounds like nutrition is an issue for you."

"Actually, I'm a vegetarian who cooks mostly from scratch. I work for a healthy living website, and nutrition is one of the topics I cover. I eat when I'm hungry, but I eat pretty healthy most of the time."

He changed gears.

"Let's look at your body fat percentage."

He pulled out a chart.

"Yours is here," he said, pointing to his chart's section for above average. I looked more closely at the chart. I'm familiar with the categories for body fat percentages, and the gym's chart was off. According to the American Council on Exercise, a woman with 21%-24% body fat is in the "fitness" range; 14%-20% is "athlete" range. ACE tells me I'm in "fitness" range; the gym tells me I'm "above average."

"We want to get you here," he said, indicating the "fit" range on his chart, which started much lower than the ACE chart. "Now let's get started."

He called over another trainer, who started my workout.

For 25 minutes, the trainer led me through a series of exercises that pushed my limits. Full pushups to plank to forearm planks, several kettlebell exercises, more squat than I care to remember, and several straight-leg abs exercises.

Just halfway through the workout, when the trainer was checking his phone instead of checking my form, I knew that this would be the first and the last workout I would do with him. (Better to break up with a trainer sooner rather than later!) I couldn’t wait to get to work today to tell Coach Nicole all about this workout--there were so many things he did that would have made her cringe!

From giving me no instruction on kettlebells to asking me to go way too low in squats, then focusing on abs exercises that--I repeatedly told him--compromised my lower back by forcing it off the mat, I knew I had a blog post in the making.

I will continue to go to the gym, but I will look to other fitness professionals (and our Exercise Demos) to help me integrate strength training into my routine.

Not only is my body in the best shape of its life, but so is my mind. I'm confident about my body, and I accept my flaws. I will never have a bikini-ready belly, and I'm OK with that. I love myself, and anyone who tries to tear me down--even for the sake of "toning me up"--has no place in my life. I could have much lower body fat if I spent more time in the gym or restricted my eating. I don't want to do either of those things. I eat right, exercise regularly, and I'm at a happy weight.

Let my experience be a lesson for you.

1. Don't let anyone try to deflate your self-esteem. Regardless of your fitness and health goals, your self-worth is not determined by a number on the scale or your body fat percentage. If a trainer doesn't respect the hard work you're doing to reach your goal, find someone who does!

2. A trainer is not a dietitian, a therapist, or a pharmacist. Know what they can recommend and what they can't. (Learn more about what to look for in a trainer.)

3. Don't be afraid to say no. I knew heading into my "free" session that the trainer would try to sell me a year's worth of sessions. Though I told him early on that I usually work out at least five days a week, he tried to tell me I wasn't committed to fitness. I thanked him for his time and told him I didn't want any sessions. "You won't be back," he said. Um, to the gym, yes. To you, no.

Trainers can be a valuable resource along the road to a healthier you, and I know people who credit theirs in large part for their success. My experience was, I hope, a rare one. I don't want to single out one person or one gym (I won't name names), but I hope you'll remember my experience when you're out shopping for a gym or a trainer. A few years ago, when I first tried to lose weight, I went to gym that offered a free session every three months. The trainers there were wonderful, and I wish I could have afforded regular sessions because then, unlike now, I needed the motivation. (Take our quiz: Do You Need a Personal Trainer?)

Have you ever used a personal trainer? What results did you achieve? What would you have done if you were me?