Are you working out the wrong way? A fitness trainer shares the common mistakes she sees.

If you’re making an effort to work out more often, it’s likely because you’re looking to improve your health, increase strength and maybe even make everyday tasks easier to perform. However, it’s not just consistent exercise that leads to those positive outcomes, but also doing your workouts using proper form.

It’s something that Beth Nicely, a National Association of Sports Medicine (NASM) certified personal trainer, corrective exercise specialist and founder of New York-based fitness studio the Limit, emphasizes in her instruction for clients of all fitness levels. “There’s so much bad form, and a lot of people just don’t know it. But if you do things in bad form, over time you’re going to injure yourself,” she tells Yahoo Life. “You’re going to get a muscle imbalance and you won’t get the benefits that you’re supposed to get from that specific exercise.”

While Nicely says people should be “applauded for just working out,” she explains that correcting errors in form can be the key to better performance overall and getting rid of any discomfort such as knee or back pain. Here, Nicely lays out four ways to address some of the most common mistakes to ensure a more effective — and safer — workout.

Be mindful of your knees

If you notice your knees drawing toward each other during a squat, lunge or jump, you’re not alone. It’s a “very common structural issue,” according to Nicely and most noticeable during those moves. The key, she says, is to keep your knees aligned with your second and third toe.

“If you continue to do exercises where your knees don’t stay aligned over your second and third toe, you’re going to have ankle issues, you’re going to have knee issues, you’re going to have hip issues because it’s all connected. And a lot of the time, the knee valgus” — when knees cave in — “is stemmed from weak hips,” she says. However, the simplest advice is to keep the knees and toes facing the same direction.

Keep a flat back

Keeping a flat back when doing movements that target the triceps, like a bent-over row or extension, helps make sure that the correct muscles are activated. “Everybody is just more hunched over from computers and phones. It’s a common postural thing that everyone just needs to be aware of,” says Nicely. “What I see is not enough activation in the muscles between your shoulder blades.”

She suggests focusing on squeezing your shoulder blades together, rather than using arm strength. Keeping your back flat and resisting the urge to round the shoulders will help.

The same goes for abdominal exercises done while lying on a mat. “You want to make sure that the work’s not going into your lower back when you do abdominals, and the way to do that is to try to keep your back flat on the mat,” she says. “An excessive arch of the lower back could cause a lot of different muscle imbalances.”

Place palms flat on the ground

Burpees and planks might not be your favorite exercise, but Nicely says to do them correctly, you need to have your palms pressed into the floor. The alternative she sees are people with just their fingers making contact with the mat, which she says will put stress on finger and wrist joints.

“If [the weight is] just in your fingers, it’s going to work your forearms. If it’s in your palm, it’s going to go more to your triceps and biceps — your actual arm muscles,” she says. “Your palms should always be flat in exercises like that.”

She also warns that exercises in a tabletop position should be done with either both hands on the mat or both elbows for the sake of your spine. “There’s a trend in fitness to do a leg series with one elbow down and your other hand on the mat,” she says. “It just twists your spine too much and there’s too much connecting in your hips and core.” That imbalance can cause lower back or neck pain, she says.

Focus on your breath

You’ve likely heard a fitness instructor remind you to breathe in the middle of a workout — that’s not just to ensure that you make it out alive, but also to make the exercises easier to perform and more effective. “Breath work is huge,” says Nicely. “The rule of thumb is that you always breathe out from your abdomen when you’re doing the work or exerting the effort. So if you’re going to do an overhead press, when that arm goes up, you breathe out. It helps engage your core to help with the press.”

Nicely admits that it’s difficult to do a move perfectly with each rep but says that “just working on it and getting better at it is important.” She adds: “Everyone has good intentions when they work out, but we want our bodies to be working functionally and as healthily as they possibly can so you do get the correct benefits.”

If you have any doubt about your form, Nicely suggests doing your workouts in front of a mirror so that you’re able to pay close attention to your movements. And if you’re seeking more information on proper form, she isn’t against searching online. “Just make sure that your resource is a certified trainer,” she says.