When it comes to fitness, there are several things that can make an impact on your progress; from your diet to your own personal drive and resolve. One thing that can make a whole world of difference? Your personal trainer—or lack of one.

With the help of a personal trainer, you’ll find it easier to see how far you’ve come. You’ll also be guided on how much further you need to go to attain your fitness goals. Having a personal trainer means having at least one person in your corner, giving you the encouragement you need to do personal trainerjust one more rep or one more set, or to push yourself beyond your limits.

To be effective, though, a personal trainer needs to be a mentor as well as a motivator. So how do you find one who can provide the right amount of discipline and understanding? Here are some of the most important qualities to look for.

Quality #1: Focuses on behaviors instead of blaming people.

Would you want to keep working with a personal trainer who calls you undisciplined, lazy, or anything else that’s just as much of a putdown? Chances are, you’d feel unmotivated after just a short time with them—which can jeopardize your progress for that day.

Look for a trainer who focuses on what’s causing the unwanted effect. It’s the difference between being told that the junk food you’re eating is unhealthy and contributing to your weight gain and being told flat-out to just stop eating otherwise you’re never going to lose weight.

Quality #2: Gives positive feedback along with constructive criticism.

Important Qualities to Look for in a Personal Trainer1Which is better to hear?

“You’re still doing this exercise wrong,” or “You did more reps this time—that’s great! But there’s still something off about your form.”

Many people would want to hear the latter instead of the former, and with good reason. Secretly or not, we all want to be praised because it makes us feel like we’ve achieved something.

If your trainer keeps pointing out where you fall short, it won’t be long before you start feeling discouraged. On the other hand, if they focus more on the little victories, you’ll feel even a little more energized to do better the next day, and the day after that, and the day after that … you get the picture.

This is particularly true if your trainer gives you ideas for improvement, especially in areas that need it. Rather than floundering about trying to get better, you’ll have a clearer path forward, making the idea of improving one thing or another less daunting.

Quality #3: Knows how to challenge you.

Let’s get this straight: anyone lifting a certain weight, or running a certain distance in so many minutes didn’t start out that way. They began lifting just 5 or 10 pounds; struggled to run just 100 meters; had difficulty cranking out just five pushups.

The point is, they had to start somewhere. So do you.

A good trainer will know how to get you started on your fitness regimen, and how to help you keep your momentum up. They’ll know how to work with you so you run into a little difficulty during the workout, but not so much that you’re uncomfortable and have to end the session early because you’re too tired to finish.

Remember: you’re looking for someone to be accountable to, who can help you stay on track, and help you be disciplined enough to follow a fitness plan made for you. But how can you tell whether they can do all that or not?

Just keep an eye out for the qualities above.

There are no shortcuts when it comes to getting fit; the personal trainer you choose needs to be able to guide you every step of your personal fitness journey. And they can’t do so properly without these qualities.