Want to take your fitness routine to the next level? Working out with a personal trainer can actually boost the success rate of achieving your fitness goals by more than 30 percent, according to a study by the Journal of Sports Science & Medicine. So whether you want to get in shape for the summer, beat the competition in a marathon, or just feel better...go for it! Hitting your goals can come a lot easier if you’ve got a coach on your side.

But before you can hit the ground running, make sure that you know what you’re signing up for. Hiring a personal trainer can be pricy—the cost ranges from $15 to $100 per hour, according to the National Strength and Conditioning Association. And that may be in addition to a gym membership fee. “This is an investment in your quality of life,” says Gunnar Peterson, the Head of Strength and Endurance Training for the Los Angeles Lakers and a celebrity fitness trainer based in Beverly Hills. “Your gym experience improves everything you do outside of the workout itself.” If you’ve decided to try working out with a trainer, not only will you work out smarter, hit your goals faster, but you may actually make a new friend, too.

Just like finding the right hairstylist and doctor, finding the perfect personal trainer takes some time. And you don’t need to stick it out with someone just because they’re the first person you picked. “Your intuition is your best friend here,” says Ruggero Loda, founder of Running Shoes Guru. “If you're excited to get to each training session, eager for your next workout and optimistic about your sport, that's a good sign. If you feel guarded about your trainer, aren't motivated to work out or even dread your personal training sessions, you probably need someone different.”

Part of that exchange comes down to compatibility. Personality and training style really go hand in hand. If you pick things up quickly, you’ll probably roll your eyes if your trainer shows you the same thing over and over again. Along the same lines, are you going to annoy your trainer? It’s definitely possible. If you are a sarcastic complainer, you’ll want to make sure your trainer gets your humor.

Keep an eye out for red flags in your first meeting, too. For example, if the trainer doesn’t do an initial assessment, be worried. “These assessments don’t always have to be measurements (some clients may not want them), but there should be strength tests, mobility screenings and a health history to go over before jumping straight into a workout,” says Hannah Daugherty, CPT-NASM and fitness expert, who serves on the advisory board for Fitter Living.

Personal training is not for the faint of heart, and certainly takes exercise to a new level. If you’ve tried a P90X DVD and found yourself pushing the pause button, get ready to match that with your personal trainer (likely without the pause break).

Your personal trainer will push your body to its breaking point, watching you lift, plank and squat more than you ever expected. It’s natural to want to stop, to listen to that voice in your head that’s screaming, “I’m done! I can’t do this for 10 more seconds!” This is where your personal trainer will show his weight in gold. He will know what you can really do and make sure that you’re doing it.

You may be surprised to see how much harder you want to work once you find the right trainer. “Psychologically, there seems to be something that makes you want to or try to perform at a higher level,” says Charlene Bazarian, who shares her weight loss story at fbjfit.com. “I found that I always pushed myself much harder when I would train with my personal trainer, than when I would work out alone. I found myself wanting to make my trainer proud of how hard I was working, as well as not to be perceived as not capable or as out of shape as I probably was when I started. I found this really had an impact on my motivation level and effort.”

There are only so many fitness-related topics you can discuss with your personal trainer. They’ll naturally try to create a more comfortable atmosphere by getting to know you. Depending on your schedule, you may even see your personal trainer more than your friends and family. Part of the appeal of opening up to your trainer is the fact that you can count on an objective opinion. Your mom or best friend may want to sugarcoat your outfit, but your trainer is focused on making sure you’re the best version of yourself.

The more comfortable and confident you get in your workouts, the more you’ll start opening up. You’ll tell your trainer about a fight you had with your boyfriend or unload about a stressful project at work. “If someone uses their workouts as a place to vent and offload emotional baggage, that can be very liberating,” says Peterson. “I make it a point to listen, rather than give advice because that’s not my area of expertise. I can help you walk through bouts of over eating or excessive partying, but I believe that giving life advice should be left to trained professionals. In the meantime, let’s knock out this set of squats, OK? That’s how this trainer does therapy.”

To give clients the results they want, a good trainer has to go beyond the physical workout. “I've had clients who are not losing weight, and I had to dig to find out that they're going out and drinking every weekend,” says Nerissa Zhang, CEO and co-founder of The Bright App. “Many people who struggle with weight and fitness have some bad habits that are preventing them from success. As a trainer, I have to figure out, case-by-case, and address them.”

If you worked with a trainer for a while and you're not getting closer to your fitness goals, it might be time someone new. “At the end of the day, you should view it as a business relationship,” says Zhang. “It’s important that you still evaluate the training aspect of the relationship by itself. Are you getting stronger? Are you making progress towards your goals? When this is no longer the case, it's important to be up front and professional about it.”

You can look at the pictures on the side of the machines at the gym for instructions on how to use them, but you’re on your own with free weights. Yes, there’s a mirror to help you watch your form, but you might still come home feeling unexpectedly sore...or worse. "A surprising or unexpected benefit of working with a personal trainer is that they significantly decrease the likelihood of injury,” says Kelly Bryant, a certified yoga instructor and personal trainer. “Personal trainers will teach their clients the correct form and fix any incorrect movement that may have previously made them prone to injury." Training is expensive, but the price can outweigh the cost of an injury.