5 Fitness Exercise Myths That Need to Be Retired Once and For All

Do you believe in these exercise myths?

If you read fitness articles online, you’ll inevitably see claims about exercise that aren’t backed by science. In the bodybuilding community, these are sometimes referred to as “bro science.” In addition, truisms about fitness training continue to change and evolve as new studies come out. Exercise science is always changing as new research comes out. To complicate matters more, the myths are simply ideas that are now outdated or obsolete but still continue to circulate. Now, let’s look at a few fitness and exercise myths that have been slow to die.

Exercise Myths #1: Stop Exercising and Muscle Turns to Fat

Muscle doesn’t turn to fat and fat doesn’t turn to muscle, no matter how lazy you are. That’s because they’re two distinct types of tissue. But, if you stop working your muscles against resistance, the muscle you have will atrophy or become smaller. It’s also likely that you’ll gain fat tissue if you continue to eat the same way you did when you were exercising regularly. So, your body fat percentage will rise, and you won’t look as lean. The ratio of each type of tissue has changed and you have a different body composition, but one didn’t turn into the other. The best way to prevent this is to stay active!

Exercise Myths #2: Sit-Ups and Crunches Help You Lose Tummy Fat

If only it were that easy! Doing hundreds of crunches won’t banish belly fat. You may develop the muscles underneath the fat through ab training, but if the belly fat won’t budge, you won’t see them. Crunches and sit-ups don’t burn enough calories or create enough of an anabolic response to burn significant belly fat. For that, you need high-intensity interval training and resistance training using heavy resistance. And don’t underestimate the importance of nutrition for shedding belly fat. Cut out the sugar and processed carbs and eat, whole, nutritious, fiber-rich foods instead – and lots of non-starchy vegetables and lean protein.

Exercise Myths #3: Squats Are Bad for Your Knees

As long as you use good form, squats actually help protect against knee pain and injury. They do this by strengthening the quadriceps muscles in the front of the thighs and the hamstrings in the back, the muscles that stabilize and protect your knees. The key is to focus on your form. When you squat, your knees should stay in line with your feet and shouldn’t move beyond the tips of your toes. Avoid bending forward or letting your body fall forward when you squat. Work on your form using light weights or no weights until you master the mechanics of the movement. It’s not that squats are bad for your knees, it’s doing bad squats!

Exercise Myths #4: Exercise is the Best Way to Lose Weight

We tend to underestimate the calories we eat and overestimate the calories we burn through exercise. Although you expend calories when you work out, it’s easy to compensate for those calories with a single, post-workout snack, especially if you make the wrong choices. For example, it takes 105 minutes of running to work off an 8-oz. bag of potato chips. If you’re eating lots of calorie-dense food, you’ll have to work out hours a day to get into a calorie deficit, if you can do it at all. You’ll end up overtraining or burning out.

Yet, you need exercise for healthy body composition. Nutrition is king, but you still need exercise for healthy body composition. If you restrict calories and exercise, you’ll lose more muscle than you will if you reduce your calorie intake and don’t exercise. The goal should be to lose body fat while retaining as much muscle as you can. Strength training helps you preserve muscle mass but also to increase muscle size.

Exercise Myths #5: Aerobic Exercise is the Only Type of Exercise with Health Benefits

Aerobic exercise improves cardiovascular fitness and can lower your risk of heart disease, but resistance training has a long list of health benefits as well. Training your muscles against resistance helps preserve muscle and bone tissue so that you’re still functional as you age and avoid falling and fracturing a hip. Plus, a study published on the Harvard Health site showed that resistance training positively impacts brain health as well. The study found that older people with mild cognitive impairment who weight trained experienced improvements in memory.

As an added bonus, studies show resistance training enhances insulin sensitivity. By improving insulin sensitivity and metabolic health as well as reducing visceral body fat, resistance training may lower the risk of type 2 diabetes and cardiovascular disease. In fact, one study found that type 2 diabetics who started lifting weights experienced improvements in blood sugar equivalent to adding a second diabetes medication. That’s the power of working your muscles against resistance!

Exercise Myths #6: You Can “Tone” Your Muscles by Lifting Light Weights

Usually, people use the term “toned” to describe muscles that look lean and not bulky. But, this term is inaccurate. Muscle tone actually refers to how contracted a muscle is when it’s at rest and has nothing to do with its appearance. Nevertheless, people use it to describe how a muscle looks. The idea is that you can get that lean, non-bulky look by lifting light weights and using high repetitions. But, the best way to lean down and have some muscle definition is to trim the fat off the muscle through calorie-burning exercise and by maintaining a slight calorie deficit. Then, build and strengthen the muscle underneath by lifting challenging weights.

Contrary to popular belief, women typically don’t bulk up when they lift heavy unless they have a condition like polycystic ovarian syndrome where they have higher levels of testosterone. If you train heavy and watch how you’ll eat, you’ll have some definition to the muscle and the muscle will be more visible as you lose body fat.

Lifting light weights and doing high repetitions mainly enhances muscle endurance and doesn’t change the size or shape of the muscle unless you take sets to near failure – and that takes a lot of time. It also doesn’t burn a lot of calories or help you shed body fat. You’ll get more return on your time by doing a combination of moderate and high-intensity exercise that gets your heart rate up and lifting at around 60 to 80% of your one-rep max.

The Bottom Line

Keep reading and educating yourself so you won’t fall victim to every fitness myth that’s out there. And, there are lots of out there!



Harvard Health Publishing. “Weight training may boost brain power”
Arch Intern Med. 2012 Apr 23; 172(8): 666–668.
Diabetes Care 1998 Aug; 21(8): 1353-1355.
Medscape.com. “Resistance Training Benefits Type 2 Diabetics”


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5 Biggest Myths about Female Strength Training

5 Myths About Fat Loss Dispelled

Is the Idea of Toning Muscles a Myth?

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