Common Myths & Misconceptions About Fitness

Hello! It’s me again. Your friendly neighborhood exercise scientist ready to stir up some trouble.

There are dozens of articles out there on this subject. But if this is the first time you’ve stumbled upon an article like this, welcome!

There’s a lot of information out there on the internet and we all know this. We all also should acknowledge that we shouldn’t believe everything we read on the internet. So if you believe what I write about here or not, that’s up to you, but do realize that I’m an exercise scientist and certified strength and conditioning professional. I’ve conducted my own research study when studying for my Bachelor’s in exercise science from Seattle Pacific University and frankly, I’m a geek for this kind of stuff!

And as I’ve stated before, one of my passions and my mission to help clear the waters on everything related to fitness and nutrition and present you all with reliable information, pulled from up-to-date research conducted by leaders in the industry. I’m doing all the research so you don’t have to!

There are a few misconceptions I hear often still that need to be put to rest, because they’ve been proved, time and time again, to simply not be true.

“I don’t deadlift because it’ll hurt my back.”

“Squatting is bad for your knees you know. You really shouldn’t be squatting past parallel.”

“Oh yeah I hurt my wrist so I’m taking a break from the gym for a month or so.”

“I don’t lift weights because I don’t want to get bulky!”

“OMG, I’ve been doing so much cardio. Working for that beach body!”

“Oh are you sure little Josie should be lifting that dumbbell? I don’t want her growth to be stunted!”

*cracks knuckles* I’ve laid out information from what current industry leaders are saying and updated research claims. I hope that you find all of this information to be sensible and that it gives you a better understanding on how the human body works and adapts.

Deadlifting is bad for your back 

First of all, back pain and injuries causing back pain can prove to be an extremely complex subject. There are varying reports from people who have had horrible MRI results, with bulging or herniated discs, disc degeneration, etc., but have no presence of low back pain, to people who have perfect MRI results showing no pathological issues but experience debilitating back pain. Back pain can cause people to miss out on activities they love to do, skip workouts that may actually help their pain, and live more sedentary lifestyles, which can lead to another host of issues. Pain itself is an incredibly complex subject. 

But deadlifts and back pain. I imagine if deadlifts were bad for your back that every powerlifter who’s ever trained to compete has crippling low back pain and can barely walk. This is not the case so are deadlifts actually as bad for your back as “gym experts” claim? So why are people avoiding deadlifts, even if they aren’t already experiencing low back pain? And why do predominantly sedentary individuals experience back pain – they’re certainly not performing deadlifts!

A study in 2015 by Berglund, et al. showed that individuals reporting low back pain had improved symptoms after training the deadlift exercise for 12 weeks. The researchers emphasized appropriate movement technique in the first few sessions and gradually introduced resistance to improve strength. By improving the quality of their movement patterns and strength levels, individuals in this study experienced improved symptoms at the end of the 12 weeks of the study.

“What is the worst possible outcome that could happen if you decided to get strong? Of course, we can all potentially hurt ourselves, but being deconditioned and rotting away is a whole lot more dangerous than picking up a barbell.”

Dr. Greg Lehman has a lot of great articles on his website relating to back pain, injuries, and asymptomatic MRIs. One of his blog posts states “Contrary to common beliefs, our findings suggest that cumulative or repetitive loading because of higher body mass (nearly 30 pounds on average) was not harmful to the discs. In fact, a slight delay in L1-L4 disc desiccation was observed in the heavier men, as compared with their lighter twin brothers.” This was pulled from a research study in 2010 by Videman et al.

Different deadlift variations all incorporate the hip hinge, which is a fundamental movement pattern. The hip hinge is such a crucial movement to be able to perform with efficacy as it helps separate lumbar flexion from hip flexion helping the individual to maintain a neutral spine. The dominant view in present research shows that a neutral spine is optimal for performing most exercises and tasks, as it puts the spine in a low risk position for injury. The hip hinge is also a common denominator in movements such as squatting, deadlifting, kettlebell swings, hip thrusts… even picking up something up off the floor involves the hip hinge movement pattern. In other words, if one can master the hip hinge, their exercise and movement toolbox expands greatly.

Here’s the thing – any physical activity or endeavor carries some level of risk for injury. But when a movement’s benefits outweigh the risks, especially when done correctly under the watchful eye of a professional, why avoid it? By training the deadlift or deadlift variations, you increase strength and movement efficiency in the hip hinge patterns.

Dr. Tyna Moore puts it the best: “What is the worst possible outcome that could happen if you decided to get strong? Of course, we can all potentially hurt ourselves, but being deconditioned and rotting away is a whole lot more dangerous than picking up a barbell.”

Squats are bad for your knees 

This is another common misconception that I hear mostly from people who have preexisting knee problems. I also hear this from people who simply lack education about how the body adapts to movement and joint tolerance to load.

I’ve said it before and I’ll say it again; the body is extremely adaptable to the stimulus placed upon it! So when people argue that squats are bad for your knees and that you shouldn’t squat past parallel, they are speaking from archaic research that needs to be put to rest.

Many other fitness professionals agree with me that squatting past parallel is safe for the knees and, in fact, will yield better results for muscle growth and strength than cutting your range of motion short. Now while I do agree that squatting deep may be harmful if your joints are not prepared to handle that range of motion, it is also a way to build a joint’s tolerance to load and range of motion. And since the knee is meant to bend, we ought to train in a way to allow the knee to safely come into full range of motion.

Running and squatting have similar compressive knee forces, except that running involves a crap-ton more repetitions. So if you have knee problems, you really should avoid running more than squatting.  

In a scientific review by Tony Ciccone, Kyle Davis, Dr. Jimmy Bagley, and Dr. Andy Galpin, they found that squatting above parallel actually increased the stress on the ACL (anterior cruciate ligament) and PCL (posterior cruciate ligament) of the knee (BOO!) Squatting below parallel reduced the forces on the ACL and PCL (WIN!), even though the overall compression on the knee joint itself increased. However, the amount of compressive force going through the knee joint in a deep squat position was comparable to the amount of force going through the knee while running. This is something to take into consideration when prescribing running distances; running typically has a lot more repetitions than a squat workout has squats.

Current research shows that squatting inherently isn’t dangerous or bad for your knees. However, individuals with contraindications and injuries concerning the lower limbs may need modifications for lower body exercises. I highly suggest hiring a coach who’s experienced in strength training for rehabilitation and competition in order to ensure your safety and movement efficacy.

If I’m injured I can’t workout 

This is a very valid concern that people have; if you’re injured, you need to rest and recover. What people do not realize is that simply sitting around and being sedentary is one very ineffective way to speed up the process of healing.

An article on by Paul Ingraham states that “Wearing the muscles out, by any means, is usually good enough for the average person or even the average athlete.” When you wear your muscles out, you are essentially creating microinjuries that the body responds to by – big surprise – healing. Training while injured could actually speed up your healing process since exercising creates a healing response in your body.

If you have a broken leg, you can still train your upper body, your torso, and… your other leg! In fact, there is a physiological concept called the crossover effect. If you train one side of your body, there is a neurological crossover to the other side of your body. So, by strengthening your right leg, you’re also strengthening your left leg, even if you’re not working out the left side at all!

So, in fact, you can train even if you’re injured. But by all means, you should be exercising under the discretion of your physical therapist and avoiding exercises that directly affect the injured body part.

Worried about keeping up your cardio while injured? Make sure your strength training! To think you need to be working your heart to improve your cardio is an outdated concept. In fact, if you work your skeletal muscles via resistance training, they can become more efficient and demand less from the heart. So, if you’re an endurance athlete who needs a high aerobic capacity, but you’re injured in a way where you have to avoid running, biking, or any repetitive movements, strength training is a great way to speed up your healing process while still helping your cardiovascular fitness.

So, if you’re injured, train as much as you can! Make sure you are following the directions of your healthcare physician and physical therapist. However anecdotally, if you are under the care of a doctor or therapist who tells you to completely lay off any sort of activity, I would encourage you seek out a second opinion.

Lifting will make you bulky – heavy weights make your muscles bulky; if you want to tone you need to use light weights and lots of reps

 “The goal is not to become a smaller version of yourself. It is to change your body composition so that you have metabolically humming muscle, less fat, and a strong body that is resilient.”

From my own experience, I can call absolute BS on this. And while “bulky” is subjective and what some women may consider to appear as “bulky”, may be completely desirable to other women, if you take a step back and look at this subject from a objective standpoint, women simply do not have the hormonal profile to build muscle mass like men do.

“I don’t want to look like a man!” 

Honey, don’t worry. You can’t. 

If you touch one heavy weight, you won’t immediately turn into the Hulk. If you go on one run, you won’t immediately turn into a marathon runner, so why assume that if you lift weights once, you’ll get huge? This often holds a lot of women back from starting strength training. That, and the pure intimidation that comes with being a woman trying to make her way into a male-dominated weight room.

So, a lot of women make the mistake of using extremely light weight for an excessive amount of reps (15+). Instead of lifting weights to build strength, they do Pilates, yoga, and core blast classes. While this sort of resistance training does have its place in a training program, heavier loads with less reps also has their place in a well-rounded training program.

Let’s look at this from a completely objective standpoint.

Lighter weights and more reps tend to hit more of the slow twitch muscle fibers. These muscle fibers are used when you’re doing slower, more aerobic activities. These muscles tend to be less metabolic, have less mass, and are oxygen-dependent. Heavier weights and less reps use more fast twitch muscle fibers. These muscles are responsible for fast, anaerobic movements and tend to be more metabolic, use more glycogen (carbs), and are not dependent on oxygen.

The problem with just working slow twitch muscle fibers is that it tends to down-regulate your metabolism. Because you’re not stimulating enough muscle, your metabolism slows down and your body becomes more dependent on fat for energy. And while this may seem desirable, boosting your metabolism to be faster while you’re at rest is a more efficient way to change your body composition to lose fat and build muscle.

Stimulating your fast twitch muscle fibers is a more efficient way to boost your metabolism, which makes you burn more fat at rest. This helps reduce the dreaded “skinny fat” appearance, will help increase muscularity in your arms and legs, giving you a more toned appearance, and build that bubble butt!

At the end of the day, this is not just an aesthetic issue. This is a case for a healthy metabolism. This is a case for a healthy body. You want to be putting on metabolically efficient muscle and increasing your bone mineral density. Again, Dr. Tyna Moore says “The goal is not to become a smaller version of yourself. It is to change your body composition so that you have metabolically humming muscle, less fat, and a strong body that is resilient.”

You need to do cardio to lose fat 

Ahh… Walking into an LA Fitness and seeing all these people running for hours on the treadmill or stairmaster to lose fat. While cardio is a great way to burn calories… while you’re doing it… it’s not a great way to keep burning calories when you’re done with your workout. Muscle is more metabolically active than fat is so if you build more muscle, you burn more calories at rest which is helpful when trying to create a caloric deficit to lose fat!

Research has also shown that resistance training may be more effective than cardio to lose fat. A study conducted by Wake Forest University in 2017 looked at the effects of resistance training on a caloric deficit versus walking on a calorie deficit in older adults with obesity. The study found that resistance training on a caloric deficit resulted in less muscle loss but significant fat loss compared to walking alone. In fact, the adults who were just walking lost more muscle mass which resulted in loss of knee strength. When walking and resistance training on a caloric deficit were combined, those individuals saw the greatest fat loss and muscle gain.

An article on does a great job of breaking down how building lean body mass (muscles) are far superior to just doing cardio when it comes to fat loss. Since muscle weights more than fat does, individuals who build muscle will actually gain weight. The numbers on the scale will go up. But this isn’t a bad thing.

People often equate fat loss with weight loss. This is simply not the case. The Precision Nutrition article lists several ways you can lose weight and they include, but are not limited to, amputation, osteoporosis, and coma. So you can see that losing fat and losing weight are not the same thing and cannot be compared.

To lose fat, you want to be improving your metabolism. Yes, cardio is a good way to lose weight – but are you losing muscle? Or fat? And from what I’ve just outlined, which do you want to lose and which do you want to hold on to? Often times, cardio results in people losing muscle mass. Which is bad. Losing muscle mass not only results in losing strength, but also downregulating your body’s metabolism. A downregulating metabolism = less calories burned at rest. Less calories burned at rest = less fat loss.

So if you want to lose fat – not lose weight – and build lean body mass (muscles) to achieve that lean toned figure, you need to ditch the treadmills, stop walking, and start lifting weights!

Lifting will stunt your growth

Besides working as a personal trainer, I’m also a strength and conditioning coach at an athletic performance facility and we work with a lot of youth athletes. I hear this often: “Lifting weights will stunt my child’s growth!” I hear this from many misinformed parents, who mean well. But come on! Leave the training to the professional who you’ve paid good money to! Besides stunting growth, parents tend to also be concerned with safety. Lifting weights is actually one of the safest activities out there, especially for a child to do, simply because of how closely monitored it is.

According to the National Strength and Conditioning Association (NSCA), fewer than 1% of injuries occurred from weight room resistance training. More injuries are reported with traditional field and court sports such as soccer, football, softball, baseball, and volleyball. In fact, from my own experience, we see more injuries in the kids that we work with after their coaches have made them run or sprint for conditioning.

There is now an abundance of research that has shown that lifting weights does not have a detrimental affect on a child’s growth, nor does lifting weights as a child pose anymore of an injury risk. In fact, strength training could decrease injury risk.

Injury occurs when a tissue (bone, muscle, tendon, etc.) cannot tolerate the amount of load (force) going through it. This can be seen when a force (falling out of a tree) results in a broken bone. Strength training helps increase the load tolerance of the muscles, tendons, ligaments, and bone, which can lead to fewer injuries down the road.

Like with any sport or activity, you wouldn’t let your child learn how to tackle another player on the field without the close supervision of an experienced and studied coach. So why would you rely on your own experience to determine what’s best for your child’s training when they’re already working with studied exercise scientists and certified professionals? I highly recommend for everyone to hire a professional if they want to start incorporating strength training into their workout program, even if you’ve had experience lifting weights before.

There are still so many myths and misconceptions out there about exercise that I haven’t addressed yet. I highly suggest you hire a professional who stays up to date with the latest research and makes a push to ensure you stay educated as well. A good exercise professional isn’t afraid to correct your ideals about exercise and will help to gently shift your perspective on what works and what doesn’t. After all, if you’ve hired a trainer to help you reach your goals, why not listen to their opinion on everything related to exercise? You’re paying them good money so respect their education and expertise.

Share this blog post with someone who says that deadlifts will hurt your back, squats are bad for your knees, lifting will make you look like a man and stunt your growth, and that cardio is the only way to lose fat! It’s important that we train in such a way there we are not wasting our time in the gym. We live in a world where efficiency and speed is highly valued, so why are people and trainers still working with archaic ideals that simply are not work and are not true?

Stay Strong!

~Laura, BS Exercise Science, CSCS, Pn1

About Laura

Hi! I’m Laura Su; I’m a strength and conditioning coach based in Seattle, WA. I’m a small business owner, competitive powerlifter, dog and horse mom, and I love coaching people to help them get stronger!

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And if you’re interested in getting stronger, check out my programs!

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  1. The Journal of Strength & Conditioning Research: July 2015 – Volume 29 – Issue 7 – p 1803-1811 doi: 10.1519/JSC.0000000000000837
  6. Wake Forest University. (2017, November 1). Lose fat, preserve muscle: Weight training beats cardio for older adults. ScienceDaily. Retrieved April 11, 2020 from
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Hi, I'm laura!

I’m a strength and conditioning coach based in Seattle, WA. I’m a small business owner, competitive powerlifter, dog and horse mom, and I love coaching people to help them get stronger!

Thanks for reading my blog! Click here to check out my podcast as well!

And if you’re interested in getting stronger, check out my programs!

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