Don’t be Fooled: Top 8 Fitness Myths Debunked

Each day I get at least a handful of press releases sent to me — new products, recent studies, contests, requests for me to share info… you name it, I’ve probably gotten an email announcement or press release about it. I usually open and at least scan over each one, unless of course, they are totally insane like the Ice Cube Diet one that I deleted immediately (and then tweeted about because it was so ridiculous).

The point to this whole story is that last week I received an email from the American Council on Exercise and in honor of April Fools day, they had  identified and debunked some of the most common and popular fitness myths that have been fooling people for years. As I read through them, I realized there were several that were surprising (or would have been surprising to me several years ago) so I decided  they would be fun to share with you all today!

Fitness Myths Debunked

Myth #1: Stretching before exercise reduces the risk of injury- False. The scientific literature of the past decade fails to support stretching before exercise as a successful strategy for injury prevention. However, research does support stretching at other times, including post-exercise, to reduce injury risk.

Myth #2: Walking a mile burns as many calories as running a mile. – In our dreams.  While walking is a great physical activity, it does not require as much energy as running. Research has shown that running has a 40 percent greater energy cost compared to walking. That means you burn more calories when you run.

Myth #3: Lactic acid causes acidosis and muscle fatigue during exercise. – False. This century-old myth, linking lactate or lactic acid to fatigue, is the result of a scientific misinterpretation that has prevailed through the years.  Lactate does not cause metabolic acidosis. Furthermore, it is useful in the performance of exercise at high intensities.

Myth #4: Lower-intensity exercise puts you in the fat-burning zone, so it’s preferable to higher-intensity exercise. – Wrong. The “fat burning zone” at low intensities of exercise doesn’t even exist! The best approach is to think of energy expenditure as a calorie is a calorie is a calorie, rather than partitioning into carbohydrate and fat calories. To burn maximum calories in support of ongoing weight loss, progress to a moderate-intensity/higher-volume exercise program and include interval training.

Myth #5: Morning workouts increase metabolism better than workouts performed later in the day. – Wishful thinking. Research has clearly shown that total energy expenditure is equivalent across different meal and exercise orders. Therefore, the decision to exercise in the morning should be driven by personal preference rather than any false hopes that greater weight loss will be achieved by exercising before breakfast.

Myth #6: Muscle weighs more than fat. – Not true. Muscle does not weigh more than fat. A pound of muscle weighs the same as a pound of fat. The difference is their density. As we lose fat and gain muscle, weight may change very little, while body volume decreases as we become leaner.

Myth #7: Women who want to avoid looking bulky should avoid resistance training. – False. Resistance training does not cause women to get bulky. In fact, it is virtually impossible for women to get as big (i.e., bulky) as men due to physiological differences, such as lower levels of testosterone.

Myth #8: Spot reduction really works, especially if you want six-pack abs. – In our dreams. Research shows that if a vigorous, high-volume, core-training program is performed, fat will be reduced in the abdominal area, but not selectively. A lean midsection requires, then, a total program of core, resistance and aerobic exercise—not just a focus on the abs.

The main myths that I once believed to be true are #1, #4, #6 and #7. I’m glad to see number 4 on here as the fat-burning zone thing has always confused me. And I still hear people say that muscle weighs more than fat all the time and to be honest, I think I’ve probably said it in the last 6 months or so… oops.

Thanks again to ACE for sharing these with me! I won’t be a fool anymore. 🙂

Have any of these fitness myths fooled you before? Are there any other health/fitness myths that you know of out there that didn’t make the list? I’d love to hear them!

Happy April Fool’s Day!

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  1. A-men! Great post covering such common myths! It’s so easy to buy into these bits of “info” and then wonder why our healthy actions aren’t working how we expcected. Thanks for sharing!

  2. Great post missus! A couple I wasn’t sure about like the muscle weighing more than fat, so common that people believe that one!

  3. Great Post. I completely believed #4 and my HRM even tells me it does….

  4. Great post for April Fools – clever! I think ACE may have misunderstood what the phrase in #6 refers to, but I can see what they’re getting at. 🙂 Thanks for sharing!

  5. These are great, thank you for sharing!!

  6. Love this! I always thought that you needed to stretch before exercise to prevent injury. Thanks for sharing these myths.

  7. I think another myth would be “fad diets work.” I mean, they may work in the short-term, but it drives me nuts that people buy into the diet du jour like crazy. There’s no quick fix: eating well and exercising often is really the only “diet” that will work.

  8. Thanks for the great info. Especially #6

  9. The fat burning zone isn’t totally a myth, it’s more like misinterpreted information. At lower intensity levels, your body draws more of its fuel from breakdown of body fat than from carbohydrates; as an athletes pushes at a higher intensity levels, more and more glycogen is needed to sustain the effort. This is very important for endurance athletes, who, in long events, run the risk of depleting their glycogen stores if their fat burning capacity isn’t sufficient developed and utilized.

  10. So wouldn’t muscle weigh more than fat by volume then? A pound of anything weighs the same as a pound of something else.

    • THANK YOU for pointing this out. Major misunderstanding in the explanation. Makes me question the credibility of the other myths being debunked.

      (this is not a jab at EBF – she clearly explains that this information is from another source – I really enjoy this blog).

    • Exactly! Of course a pound of fat is the same as a pound of muscle. But if we weigh 1 cubic inch of fat versus 1 cubic inch of muscle, would they still have the same weight?

    • The saying ‘muscle weighs more than fat’ is incomplete. It is not wrong or right it’s just inadequate. A cup of muscle weighs more than a cup of fat. A lb of muscle doesn’t weigh more than a lb of fat. It’s all in the details.

      • I did a number of calculations based on statistics i pieced together from research on google. Here are the conclusions I came to…

        1 cubic ft. of muscle weighs 66 pounds
        1 cubic ft. of fat weighs 56 pounds

        which means muscle is 18% more dense than fat

  11. Hey Brittany 🙂 Thanks so much for sharing! I know a lot about food… but I have to admit my knowledge about exercise is pretty limited. Have a great day!

  12. Good post! A lot of people have very false beliefs about dieting and fitness (like my roommate who thought that she needed to eat less fruit after a fitness tracker told her she was consuming too much sugar)

  13. Myth #6 definitely shocked me!! I was totally a sucker for that myth!! Thanks for debunking these!!

  14. Great post! I think all of the best myths were busted here.
    Myth#6 is one which often confuses people. I guess the point of that myth was to get you to focus less on weight and more on size.
    It’s truly better to measure losing fat by the inch than by the pound. Who really cares what your weight is if you achieve your desired size, shape AND health goals.
    Healthy fat loss is what I always teach- not faddy weight loss.

  15. My area of focus is on the abdominals, so I found the myth of spot training most interesting to be on the list.
    As a matter of fact, no amount of any kind of training – spot or overall body – alone will help someone look toned without the support of a proper diet to lose fat. Truth be told, the diet part will make more of a difference on its own than exercise would. However, both are essential for getting six pack abs and/or a fit looking body.

  16. Great post! I love fitness myths because there are literally SO many! My favorite is drinking water during your workout will cause you to bloat more. I read this and laughed! Water is so essential AT ALL TIMES! Hope you have a great week 🙂 Love + Shine CourtStar

  17. Love this post Brittany!

  18. Nice post! This really helps because lots and lots of articles are being posted online and I am having problem which to believe and which is not. And sometimes, one post contradicts another. Myth #5 were always on articles, they said that they burn more fats if they exercise before eating breakfast.

  19. I can’t help but be embarrassed when I think back to those hours of ab exercises I performed while carrying 15 extra lbs of weight. I’m sure that six pack was under there somewhere but little good it did me!

  20. Awesome! Good chuckle for me too!

  21. Great info- thanks for sharing!

    I feel like Myth #6 is a misinterpretation/misunderstanding rather than a myth. A pound of muscle can’t weigh more than a pound of fat…a pound is a weight measurement, it’s impossible for a pound of one thing to weigh more than a pound of something else. They’re both one pound.

    I always understood it as a density difference, too – a certain volume of muscle weighs more than the same volume of fat (i.e. if you took a box and filled it with muscle, it would weigh more than the same box filled with fat. gross visual but you get the idea).

  22. I was also under the impression that morning workouts were better! Ah well 🙁

  23. I feel vindicated by #5 – I am NOT a morning person, and will never be a morning person, and I’m so tired of every person/news story/magazine article advocate for working out in the morning. I have so much more energy at night!

  24. Joujou says:

    About Myth # 6, you said that fat and muscles weigh the same thing by comparing a pound with a pound. In fact, pound is a measure of weight so if you compare two equal weight, it is expected that they weigh the same…
    Density is a mesure of mass per volume, so if muscle and fat don’t have the same density, they won’t have the same mass for the same volume…
    You should clarify this contradiction, otherwise it looses its credibility.

  25. Brittany,
    Thanks for sharing! I totally agree. I tried to debunk some of these stubborn fitness myths myself on my blog:

    No matter where I turn, I see another ‘fitness’ magazine on the stands telling me how to do more sit-ups, drink more water, or run longer to get the body of my dreams. Not only is a lot of the information misleading or completely false, these articles reproduce a one-sided beauty ideal.

    Thanks so much for the great post!

  26. I found your list… Is spot training really not possible? I didn’t know that. I want to loose my belly fat and get some nice abs. So I don’t only need to focus on my belly? Can I just do all exercises? Cheers Christian

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