strength training mistakes

Before I get into this post, you need to know that I’m a stickler for specifics. I’ve always been one to follow instructions to a T.

Having actually had OCD as a kid, I think that’s where it stems from.

So I just want you to know that no, I’m not a weirdo staring around the gym, silently criticizing all the hard-working people in there. That would be absolutely awful! I’m so happy to see a gym full of people at all different fitness stages. But I can’t help but notice when someone’s doing something wrong or inefficiently.

I am a personal trainer, after all. And I became one to share exercise knowledge with as many people as I can.

So I’m here today to tell you what I see most often so you won’t make those same mistakes.

More likely than not, you have made at least one of these common exercise mistakes in the past. I know I have!

And I’ve actually experienced injuries from some of my mistakes. Now that I’ve studied fitness and consulted with others in the field, I’d like to teach you the proper form and techniques to execute these exercises proficiently.

Please note: Check with your physician before starting any exercise routine or starting any particular diet. See this Disclaimer for more details. This post may contain affiliate links. For details, please visit my Disclosure page. Thank you!

12 Common Exercise Mistakes (and how to fix them!)

1. Leaning into Toes during Squats

A fundamental movement, I’ve seen tons of people performing squats in the gym.

In fact, they’re one of the best exercises you can do, working all the large muscle groups in the lower body

Unless you do them wrong. In which case you can hurt yourself. And unfortunately, incorrect squats are one of the most common exercise mistakes I see.

The problem

When many begin learning how to squat, they tend to lean forward for multiple reasons: to maintain balance, because they lack flexibility, or because they don’t know they should be sticking their hips way back.

One of the ways this manifests is by leaning into your toes, with the heels coming off the floor. The knees will probably go forward past your toes as well.

This is problematic because you can hurt your knees. When you put your weight into your toes, you force your legs to use the wrong muscles when standing back up. This can cause injury.

The fix

What you should do is put your weight into your heels. They should stay completely on the ground during the whole movement.


Incorrect form on left, correct form on right:

Common exercise mistakes: squats with weight in toes, knees past toes Squats correct form



2. Going too Fast on Eccentric Phase

The eccentric phase is just a fancy way of saying when your muscles are working as they lengthen. For example, when you’re lowering your arms after a bicep curl or lowering yourself into a squat.

What we usually think about is the concentric phase, the part where you’re “doing the work.” That would be bringing the weights up in a bicep curl or pushing up from a squat.

Many people think that the “doing the work” concentric phase is the most important part. But the eccentric phase is actually where you build the most muscle.

The problem

Because people don’t recognize the importance of going slow in the eccentric phase, they go way too fast without controlling the movement. This results in less “results.”

The fix

Keep the eccentric phase slow and controlled. You’ll notice you get more sore the next day – that’s because you’re building more muscle!

In the video below, I perform 2 bicep curls correctly and then 2 incorrectly:

RELATED POST: Weight Training for Beginners

3. Planks with Hands Clasped

This may be one of my biggest pet peeves because pretty much everyone does this. During a classic plank on the forearms, most people will clasp their hands together.

The problem

Clasping your hands is actually a compensation that makes the movement easier. Likewise, it takes away some of the benefit.

The fix

Keep forearms parallel, with hands either in fists or flat on the floor.


Incorrect form on left, correct form on right:

Common exercise mistakes: plank with hands clasped Plank correct form

4. Planks without Abs Engaged

Planks are such a good ab exercise – if your abs are engaged. Unfortunately, many people are missing out on all the ab benefits that planks have to offer due to this common exercise mistake.

The problem

When you don’t contract your abs, pulling them up towards your spine, you’re not fully engaging them. You also lose some benefit when you let your hips sag or raise them too high.

The fix

Every time you do a plank, suck that belly in the entire time. Keep your body in a straight line, and you’ll get all the wonderful benefits of planks.


Incorrect form on top, correct form on bottom:

Common exercise mistakes: plank with hips sagging Common exercise mistakes: plank with hips in the air

Correct plank form


RELATED POST: 10 Minute Ab Workout for a Tight Core

5. Holding onto Treadmill while Walking

Do you throw the treadmill into a steep incline and proceed to hold onto the front for dear life? Well that’s actually not a great idea!

The problem

Holding onto the front of the treadmill takes away most of the challenge. It won’t give you nearly as much of a workout.

The fix

Don’t hold on! Pump your arms, lower the incline, or lower the speed to where you’re working but don’t feel the need to hang on.

Side note: unless you have some sort of balance impairment, in which case please hold on to the railings.


Incorrect form on left, correct form on right:

Common exercise mistakes: holding onto treadmill Treadmill correct form

6. 90 Degree Push-Up/Chest Press

I used to be one of those people who put their arms out to the side at a 90 degree angle for my push-ups and chest press. I didn’t understand why they felt wrong and wasn’t sure how to fix it. Little did I know, I was performing one of the most common exercise mistakes.

The problem

The 90 degree angle won’t work all the correct muscles in the best ways. You can also strain your shoulders by doing this.

The fix

Bring your arms in more and aim for a 30 degree angle between your upper arms and your sides when you lower down for a push-up. This will properly work your triceps and chest. The same is true for dumbbell chest presses!

In the video below, I perform 2 chest presses correctly and then 2 incorrectly:


 Common strength training mistakes

Photo used in this pin was created by nensuria –

7. Bringing Hands Together During Shoulder Press

I hold this exercise completely accountable for causing my two week long shoulder pain. When most people (myself included) bring their arms up over their heads for a shoulder press, they bring their hands together to touch weights.

The problem

This strains the shoulders and can cause injury.

The fix

After researching what I may have done incorrectly, I learned I should’ve kept my arms straight in line with my shoulders when I raised them overhead.

You could also try an exercise like scaptions first to increase your shoulder strength before doing more shoulder presses. That’s what I did.


Incorrect form on left, correct form on right:

Common exercise mistakes: shoulder press hands together Shoulder press correct form

8. Bar Behind the Head during Lat Pull-downs

I see this far more often than I should. So many people believe the proper way to perform a lat pull-down is by pulling the bar behind your head.

The problem

This is dangerous and can easily result in injury.

The fix

Bring the bar to the front of you, close to your face and just down to chin level.

How to perform a proper lat pulldown

Incorrect form on left, correct form on right:

Common exercise mistakes: lat pulldown behind head Lat pulldown correct form



9. Lifting with Back during Romanian Deadlifts

One of the most common exercise mistakes, this one can lead to some serious back pain and injury. There was a point in time when I thought deadlifts were a back exercise. Even after learning that this is false (deadlifts are for the glutes and hamstrings) I myself was guilty of straining my back while performing them. Once I learned more about form, though, I learned the proper and safe way to perform them.

The problem

There are many ways to mess this movement up, so you must be diligent about form. Many people bend forward with their hands far from their legs. Many also use their back to raise themselves back up. Don’t do this!

The fix

When you bend forward, keep your shoulders back, your back straight, and your hands close to your legs. The weights should be brushing your legs as you bend. Reach down just far enough to feel the stretch in your hamstrings, then push your hips forward to pull yourself back upright. Squeeze your glutes at the top. Do not use your back!

In the video below, I perform 2 deadlifts correctly and then 2 incorrectly:


10. Swinging to Complete a Bicep Curl

I see this workout mistake all too often. People swing their arms and use the momentum to complete the bicep curl, which defeats the purpose of the movement.

The problem

When you swing your arms, you’re either not going slow enough to control the movement or the weight is too heavy. Either way, you’re not getting all you could out of the exercise. You’re also putting yourself at risk for shoulder injury.

The fix

If the weight is so heavy that you’re starting to compromise your form, you need to decrease the weight. Either that or rest until you’re ready for your next set, and then back down the reps.

In the video below, I perform 2 bicep curls correctly and then 2 incorrectly:


11. Holding Stretches for Less than 30 Seconds

I had no idea there was an ideal amount of time to hold a stretch until I was studying to become a personal trainer. Not holding a stretch long enough means you pretty much get nothing out of it.

The problem

It takes 30 seconds for your muscle to relax and release. If you hold a stretch for only 15 seconds, you haven’t allowed your muscle to receive the full benefit of the stretch.

The fix

To remove this from our list of common exercise mistakes, be sure to hold each stretch for at least 30 seconds, no less.

Not stretching long enough, common exercise mistakes


12. Holding Breath During Exercise

Holding your breath during an exercise is one of the worst things you can do. Not only is it uncomfortable, you can also harm yourself.

The problem

When you hold your breath while exerting yourself, you increase your intrathoracic pressure (the pressure in your torso). This places pressure on your abdominal aorta, a large blood vessel in your torso that supplies oxygen-rich blood to your body. That increased pressure can cut off some of your blood supply, which can make you pass out.

If you don’t believe me, believe the tons of videos on YouTube that show powerlifters holding their breath and passing out at the end of a movement. It’s not because they just lifted something heavy – it’s because they held their breath.

The fix

Take deep, continuous breaths the entire time you perform a movement. It’s best to breath out when you’re exerting yourself (remember that “doing the work” concentric phase) and inhale when you’re in the eccentric phase.

12 common exercise mistakes and how to fix them
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For more on proper strength training, I highly recommend the Women’s Health and Men’s Health Big Book of Exercises. I have the Women’s Health one and absolutely love it. Not only does it have countless exercises, it has details on correct form, how to progress/regress exercises, training plans, and nutrition tips. Suitable for anyone at any point of their fitness journey!

Did you learn something new? If you did, please be sure to share this post so others can learn how to fix these common exercise mistakes too!