The 6 Worst Fitness Myths Ever

6 fitness myths

Table of Contents

Fortunately, we now have more scientific and anecdotal data about fitness and health than we did a few decades ago. Many fitness myths have been busted and you would assume that all of them are gone for good. However, for some reason, that’s not the case. Many knowledgeable researchers and top trainers did bust some of those myths, but some seem to linger around despite all the easily-accessible information. Some of those lingering myths are so stupid to a provocative point. Without further ado, let’s discuss them.

1-Sugar is Unhealthy

sugar is unhealthy
Okay, really? Haven’t many people gone over this before? Yet, most people still believe that sugar is the devil in disguise. Yes, sugar could potentially be harmful, but in larger quantities than you think. First, let’s see what people have this negative bias towards sugar.

  • Sugar is void of nutrients
  • Sugar causes secretion of insulin
  • Insulin is “evil”
  • Sugar causes insulin resistance
  • Woah, I am fat and diabetic!!
  • Sugar is addictive

So, the first two reasons why people demonize sugar is because it’s void of any nutrients and it stimulates insulin release. Frankly, both points are true and valid arguments. But this isn’t the whole picture.
Insulin is a storage hormone secreted by the pancreas after a meal. It’s responsible for taking glucose out of the blood and shuttling it to different tissues. Those cells are muscle cells, liver, and fat cells. It also inhibits lipolysis (breakdown of fat) and stimulates lipogenesis (fat storage).

  • Sugar isn’t the only food that stimulates insulin release

The fact is that while sugar does in fact stimulate insulin secretion, just about anything you eat will also cause insulin secretion. Moreover, carbohydrates (simple or complex) cause just about the same spike in insulin levels, if not more.
For instance, Boelsma et al. (2010) studied the effects of two different meals on insulin levels. Both meals were isocaloric (675 kcal). One meal contained 125 grams of carbohydrates and 21 grams of protein and the other meal contained 75 grams of protein and 75 grams of carbs. The researched observed a higher increase in insulin levels with the low carb meal! This indicates that protein has a powerful effect on insulin secretion as well.
On the other hand, dietary fat doesn’t cause insulin secretion and delays gastric emptying. Thus, dietary fat can help regulate the insulin response to meals. Oddly though, milk (and dairy) is very insulinogenic despite it having a good amount of fat.

  • Sugar is void of nutrient

And to that I say “okay, and?!”. What’s your point? Yes, sugar doesn’t have any nutrients, but not every damn thing you consume needs to consume nutrients. Plus, realistically, how much sugar could you possibly consume on a given day? Two tsp. of sugar to sweeten your coffee? G, that’s a lot (not). That’s only 30 calories out of however many you’re currently consuming anyway. What about that small piece of cake on your mother’s birthday? Come on, this is a moot point and there are better things to do in life instead of worrying about 50-75 grams of sugar you may consume occasionally.
Additionally, if you want to be technical, sugar is void of nutrient, but it’s not void of macronutrients. Sugar is simple carbohydrates after all. And carbs provide your body with energy to carry out its functions.

  • Insulin is evil

Is this still a common belief? I could’ve sworn we got rid of this one, but whatever. Yes, insulin is a storage hormone, but it doesn’t necessarily make you fat. Consistently consuming significantly more calories than your body requires combined with lack of physical activity is what makes you fat, not insulin. All insulin does is shuttle nutrients and glucose to muscles, liver, and fat cells. Your body can also store fat without insulin! Insulin inhibits lipolysis by directly inhibiting Hormone Sensitive Lipase (HSL). Dietary fat doesn’t cause insulin secretion, but it also hinders fat breakdown (lipolysis) by directly suppressing HSL. What a surprise! So, if you decide not to consume any carbohydrates, and consume only dietary fat, you’ll still inhibit fat breakdown. Another reason why low carb high fat diets are complete and utter nonsense. Acylation Stimulating Hormone (ASP), which is induced by fat, is what directly inhibits HSL and promote lipogenesis.

Without insulin, glucose would stay in your blood causing high blood glucose levels. This would cause excess glucose to be excreted in urine which would attract more water. This causes frequent urination, thirst, and could lead to dehydration. Also, since insulin shuttle glucose -energy- to muscles, liver, and fat cells, those cells would be receiving little to no energy. This would affect just about every bodily function. The energy has to come from somewhere, so the body will try to compensate by breaking down fat and muscle tissues to create energy, causing rapidly unhealthy weight loss. If this persists, patients could either go into a coma or die. This is also known as type 1 diabetes. So, yes, insulin is essential for life.

  • Sugar causes insulin resistance

Imagine insulin knocks on a cell’s door to give it glucose, but the cell is deaf and can’t hear insulin knocking. That, in a nutshell, what insulin resistance could be defined as. It’s basically when cells become resistant to insulin signaling. In turn, the body tries to force cells to accept glucose by secreting more insulin.
That said, an individual doesn’t become insulin resistant overnight. This requires consistent bad eating habits, specifically, carbohydrates and dietary fat (excluding polyunsaturated fats). That said, most insulin resistance cases are caused by obesity and lack of physical activity. For example, resistance training is well known to improve insulin sensitivity. There’s no direct relationship between sugar consumption and insulin resistance.

  • Sugar is addictive

While I was looking for a nice “sugar” picture to add to this article, I came across this wonderful diagram.
sugar is addictive
Allow me to first address that I don’t mean to disrespect the creator of this diagram, but rather illustrate the flaws in its arguments.
1- If you like a certain food, you’ll crave it occasionally. However, this goes for any type of food, not just sugar. Additionally, just because you crave something, doesn’t mean you are necessarily addicted to it. I like pasta. I highly doubt I am addicted to pasta! I crave pasta occasionally, but I don’t necessarily go out of my way to eat pasta every day. Unlike cocaine addicts who reach for the substance as a fix. Instead of saying sugar is addictive because you crave it, we could say that sugar has addictive-like qualities because of its effect on our taste buds.
If we were to remove the enjoyment element of sugar, would we crave it? No. And that’s exactly what researchers did when they knocked out rodents’ taste buds and fed them sugar. The rodents consumed the sugar but didn’t overeat. So, realistically, what makes us crave sugar is the sweet taste and enjoyment element of it, that’s all.
On the other hand, some people who don’t have a “sweet tooth” rarely touch anything sweet. They may have a piece of cake or something here and there, but that’s about it. We don’t see them reaching out for that bag of sugar and sniffing it.
2- It’s true that sugar consumption could cause a slight release of dopamine. Dopamine is a hormone that regulates enjoyment and mood. That said, whenever we do anything we enjoy, dopamine is release. For instance, I enjoy watching soccer games. When I watch a soccer game, my brain probably secretes dopamine. Does that mean I am addicted to watching soccer games? Do I sneak outside my house at night to go watch a soccer game at my friend’s house? No. Once again, a moot point that doesn’t necessarily establish a direct connection between sugar consumption and addiction.
3- Already covered above. Oh, and your body doesn’t give a crap about the “sugar high” or whatever.
4- The cycle doesn’t get repeated because there is no cycle to begin with! In fact, sugar zealots contradict themselves when stating that sugar is bad because it causes insulin secretion, which stores fat. Then they say that low blood sugar levels stimulate appetite and thus the “addiction cycle” is repeated. In fact, insulin does suppress appetite, which is partially why protein tends to be the most satiating macronutrient and why low carbohydrate followers tend to get hungrier throughout the day. That said, insulin isn’t the only hormone that regulates hunger. That’s ghrelin’s main job!
Verdict: Sugar is not fat-promoting or addictive. However, don’t go around consuming 500 grams of sugar a day. The general consensus is to eat a balanced diet composed of mainly whole foods while allowing yourself to enjoy some treats.

2- Fasted Training doesn’t cause more fat loss

I’d rather train in a fed state and lose the same amount of fat than to train fasted and feel like crap. Scheonfeld et al. (2014) investigated if fasted cardio causes more fat loss. The researchers assigned 20 women into 2 groups; fasted and fed. The fasted group performed their cardio session in the morning on an empty stomach. The fed group were given a shake immediately before their cardio session. Training volume was equated between both groups. Both groups were given diet counseling to ensure they both consumed the same amount of food.
At the end of the study, the researchers found no significant differences between groups. However, allow me to show you a somewhat interesting result.
fasted cardio myth
The fasted group lost 1.6kg while the fed group lost 1kg on average. This may seem like a significant amount, and it kind of is, but “weight” is misleading. Out of the 1 kg the fed group lost, 0.7kg was fat and 0.2kg was lean tissue. The fasted group lost more fat-free-mass at 0.5kg. So, the fasted group lost 0.5 kilograms of lean tissue along with ~ 1 kilogram of fat mass. That’s a ratio of 2:1.
But, the fasted group lost more fat!!
Uhm yes, they did. But, they also lost MORE weight! Meaning, if we were to scale up the numbers between both groups, the results would be similar. Let’s put it to the test.
Fed = 1 KG * 1.7 (to match fasted group’s weight loss) = 1.7 KG
Fat mass = 0.7 * 1.7 = 1.19 ~ 1.20 KG vs. 1.1 KG in fasted group.
FFM = 0.2*1.7 = 0.34 KG vs 0.5 KG in fasted group.
So, realistically, the fed group lost slightly more fat and retained slightly more fat free mass than the fasted group. Which is consistent with other research.
Hackett. et al. (2017) conducted a systematic review and meta-analysis on the subject and observed no significant differences between fasted and fed training.
As for fasted weightlifting, you will not perform as good as if you were to train in a fed state. Mainly because of 3 reasons:
1- You have no carbohydrates in your system. Carbohydrates are known to boost athletic performance.
2- Your muscles are depleted of glycogen. Your muscles are not as full/big as in a fed state. Logically, a larger and more hydrated muscle will contract harder and produce more force.
3- You’re dehydrated. Dehydration is known to hinder performance.
Verdict: Fasted training doesn’t let you magically lose more fat. A sustainable caloric deficit is still the number one factor in losing weight/fat. Moreover, training in a fed state is better for retaining muscle mass and overall performance.

3- Sweating isn’t indicative of fat loss

sweating and weight loss myth
Third on the list of fitness myths that need to die is the infamous “I am sweating, therefore, I am burning fat”. Sweating is indicative of one thing; high core temperature. On paper, sweating may seem like a good marker of effort and thus fat loss. But, that’s not the case.
This myth seems to originate from our exposure to pop culture that promote that idea, and humans’ tendency to oversimplify things. Sweating is merely a mechanism by which our bodies regulate temperature. If it wasn’t for sweating, one would overheat and die. Have you noticed that you sweat more during the summer?! Voila!!
Sweating causes our bodies to excrete water. Thus, training in hot temperatures with the intention of sweating as much as possible could lead to overheating and dehydration. Ever noticed why athletes to get heat strokes?
In fact, excessive sweating leading to dehydration can and will affect your heart function, kidney function, nervous system, body composition, performance and could potentially cause you to end up in the hospital. [1,2]
Verdict: Sweating is merely a mechanism to cool our bodies down and prevent overheating. It isn’t indicative of any fat loss taking place. Moreover, calorie restriction is still the primary factor in losing weight. Don’t wear garbage bags, please. They look pretty f*ng stupid anyway. Train smart, restrict your calories and you will lose fat in a healthy and sustainable manner.


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