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9 Common Myths About Gaining & Building Muscle


The truths of muscle-gain can be well-hidden behind bro-science, gym lore, and internet dogma.

The briefest of browser searches will turn up all kinds of kooky nutrition and training advice. If you stick with it long enough, you might figure out how to sort the knowledge from the nonsense; but we can save you a lot of time!

Let’s pick apart some of the common “commandments” of muscle-gain—you’ll be surprised how many are fruitless, misleading, or just plain wrong.


1. Thou Shalt Eat All the Protein

The first chapter of the bro-science bible would probably expound that, to put on lots of muscle, you need to eat lots of protein. The logic goes like this: You want to put on muscle, and muscle is made from protein; so, it stands to reason that, if you want to maximize the amount of muscle your body can synthesize, you have to eat as much protein as you can. Right? Not really.

Science doesn’t back up this claim. In fact, studies that have compared the effects of moderate-protein and very-high-protein diets on hypertrophy show the contrary: after a certain point, increasing daily protein to extreme amounts will not increase the muscle you gain [1]. This doesn’t mean that you should scorn high-protein diets—in fact, high-protein diets can have other benefits including satiety (making you feel full) and muscle retention [2]. But if your aim is to gain muscle, you don’t need to guzzle every gram of whey you can find.

How much protein should you eat, then? The optimal range is probably between 0.6 and 0.9 grams of protein per pound of bodyweight (1.4 and 2.0 grams per kilogram of bodyweight) [3]. For a 150 lb person, this means eating between 90g and 135g of protein per day; or for someone who weighs 200 lb, eating between 120g and 180g per day. (Notice that, far from being a hard-and-fast number, there’s a lot of wiggle-room here.) If you’re resistance training (and you absolutely should be to build muscle!) then you don’t want to eat protein below this range consistently. However, eating protein above this recommendation might increase the feeling of fullness (if you need it), and it might satisfy a preference for meat and dairy—but it won’t make you gain more muscle.

(For more details on how much protein you really need, check out our article here!)


2. Protein Is the Only Macro That Matters

Protein is very important for gaining muscle. Your body must have a positive nitrogen balance (meaning, protein to spare) in order to spend that surplus on building muscle tissue. But protein isn’t the only thing that matters. Physics will hit you hard if you think just eating lots of protein will transform you into a Greek statue. For that, you need to eat a surplus of calories too. Just like you can’t lose weight without eating in a deficit, you can’t gain weight (and muscle is weight) without consuming more total food. The most important thing your macros will do for you here is put you in a surplus.

After total calories, second on the list is nailing down your protein intake so you’re consistently in that optimal range (0.6 – 0.9 grams/pound of bodyweight/day). But unless you were already eating tons of carbs and fats, and very low protein, simply adding protein probably won’t put you in much of a surplus.

Carbs are great for helping you eat a surplus of calories since they don’t fill you up as much (making them easier to consume in a surplus) and they’ll provide more of the fast-burning energy you’ll need for hard, muscle-building workouts. Also, carbs will stimulate the anabolic hormone insulin, which, among other things, helps synthesize muscle tissue by preventing protein breakdown and helping you reach a positive nitrogen balance [4].

3. Thou Shalt Eat All the Calories

While the laws of physics demand that you eat a surplus of calories to gain muscle, no rules require you to gorge down a pizza and a bucket of buffalo wings every day. The popular concept of “bulking”—eating as much as you can to maximize muscle-tissue synthesis—is no more scientific than “eat all the protein, bro.”

Just like how eating protein beyond 0.9g/pound bodyweight doesn’t buy you any extra muscle gain, eating ridiculously high calories doesn’t yield any increase in muscle-growth over time. Your body has a maximal capacity for synthesizing protein into muscle, and, beyond a certain point, no amount of calories will make it go faster. Those excess calories will get put to use, rest assured—you’ll find them lurking around your stomach, hips, and thighs as the softer stuff you probably don’t want.

Want to find out how fast you can reasonably (and naturally) gain muscle? Check out our article here!


4. Cardio Will Ruin Your Gains

Cardiovascular (or endurance) training can interfere with your body’s ability to increase muscle and gain strength—that much is clear [5]. Cardio takes up time and energy that you could put toward more valuable muscle-building workouts. And cardio might increase catabolism (energy break-down) in the body by stimulating catabolic hormones (like cortisol) when you want the opposite (anabolism, synthesis, growth) [6]. However, the amount cardio you can get away with (with minimal or no downside) is less clear, and needs more science to say for sure.

A hard-gainer struggling to add mass may do better by removing cardio (decreasing calories out) instead of eating even more (increasing calories in); but that doesn’t mean everyone should nix some endurance training. In fact, many studies have shown that concurrent training (endurance and resistance training within the same week), can still cause muscle growth. When groups of subjects did concurrent training, there was an interference effect for strength (meaning they gained less strength than if they had only resistance-trained) but they still gained muscle, albeit in a different pattern (only fast-twitch muscle fibers grew—possibly because the other, slower-twitch fibers were too fatigued or depleted by the endurance training) [5].

So yes, you can do some cardio and still put on muscle. That said, you’ll have to ignore another piece of prevailing bro-science: that you can do as much cardio as you want, so long as it’s HIIT. High-Intensity-Interval-Training has been touted as a cure for the interference effect between endurance and resistance training.

Since HIIT’s intensity and duration are similar to resistance training, proponents argue, the stimulus isn’t directly opposed to the process of putting on muscle, and may even help. While that’s true to an extent [7], HIIT is still an exhausting form of cardio, and can ultimately detract from the energy your body needs to build muscle, especially if performed before a lifting session. Remember that the focus of a muscle-building period should be resistance training, and that, whatever the type or mode of cardio you choose, moderation will be key.

(Want more on cardio and muscle gain? Here’s an entire article for you!)

5. Thou Shalt Do 8-12 Reps

Doing sets of 8-12 reps will build muscle, but it isn’t the only way. In fact, the idea that any particular number of reps is best for hypertrophy has been hacked to smithereens in recent years.

Let’s crush the mythology of the 8-12 rep-range…

First, understand that volume is king. Volume, usually expressed as weight times sets times reps, is the clearest predictor of hypertrophy. If the total volume of training is going up over time, muscle mass will likely follow, because adding muscle is the body’s adaptation to handle increased workloads [8]. And while 8 reps, 10, reps, or 12 reps will work fine to accomplish this, the supremacy of total volume means that no specific way of achieving it is better or worse than another. So, you can still get enough volume to build muscle with 6 reps, or 15 reps.

Understanding this simple fact is important. Some people prefer light weights and high reps (like sets of 15, 20, or even 30—those crazies), and some people prefer heavy weights and low reps (like 4-6)—both of which are in that reasonable range for muscle growth. If you think that lifting in these zones will undercut your gains, you’re missing out on what could be your favorite style of training.

Sets of 8-12 might be a convenient middle-ground for many people, straddling the line between heavy strength training and the lung- and muscle-burning adventure into higher reps. But it shouldn’t be seen as anything special, and there are downsides. A narrow range of reps doesn’t leave much room for variation or progression over time. Also, sticking to the middle-ground cleaves off the value you can get from using the ranges on either side: reps lower than 8 will increase strength very efficiently, and help you to add volume (by increasing weights) over time; reps higher than 12 will increase your work capacity, allowing you to do more work (again read: volume) in the gym and recover faster between sets and reps. Plus, the pump and burn you’d get from sets of 15-20 are hard to match with lower reps.

6. Never Exercise a Sore Muscle

There are two big reasons why this isn’t true:
1) Exercise is actually a great—possibly the best—way to get rid of lingering soreness [9].
2) Within reason, a sore muscle isn’t much different from a fully-recovered muscle.

If the pain is severe, you’ll see diminished performance and force-production from sore regions of the body [10], but you can still do light work in the gym, improve recovery, and continue trekking down the muscle-brick road.

And keep in mind that avoiding ever training a sore muscle cuts down on either the intensity of your workouts (so you won’t get sore) or the frequency of your workouts (like a once-per-week muscle-group split, or even skipping sessions because you’re still sore). Both options are unnecessary and antithetical to the point of what you’re doing: to build muscle, you have to train hard, and you have to consistently accumulate training volume over time.

7. Thou Shalt Train to Failure

Taking every set to the point of failure (where you can’t do any more reps) simply isn’t necessary to build muscle. In fact, you don’t have to take any of your training to failure. As a style of training, many studies have validated that training to failure works [8], but so does leaving reps “in the tank” at the end of a set, which is likely a better long-term approach [11].

Here’s why you should limit or avoid it: If you train to failure, your training will be more exhausting, require more rest between sets (or require you to use much less weight), and leave you with no wiggle-room for a planned progression in the weeks or months to come. For example, if you can only do 10 reps, and you do 10 reps, you can’t be certain you’ll be able to increase to 11 or 12 reps next week. Beginners may be able to, but an intermediate or advanced trainee will quickly get stuck and see their returns from the gym diminish. If you did 7-8 reps instead, you know that next week you could do 8-9, and the week after that 9-10. You gave yourself more time to get stronger, and were just as productive.

Furthermore, you’ve skipped out on the extra problems that training to failure entails, like needing a competent spotter for safety, pounding pre-workout to stave off the inevitable burnout, and the aches, pains, and injuries that are more likely when you take exercises to the max.

8. Your Workouts Must Be Long

We’ve all seen that muscle-head: He’s in the gym six days per week, and no matter what time you go, it’s like he’s always there. Maybe you go up to him and ask how long he trains, and he says “4 hours” with a proud smile. He has to train that long, he explains, because he needs to get just so jacked. It’s the only way.

Luckily, he’s wrong.. Many research studies have created lots of hypertrophy with bare-bones, short-and-simple workouts that couldn’t take longer than a half hour. Is that a solution for the long-term? Certainly not, and it is true that the longer you seek to gain muscle, the longer your training sessions may need to be. But the quest for higher volumes of training (per session) need to be balanced against the suggested downsides of gruesomely long training sessions: burnout, decreased effort and motivation, and perhaps even a suppressed immune system [8]. If someone is always taking longer than 90-120 minutes to train, they’re probably making up for poor programming and exercise selection, and wasting lots of time in the gym. This is the “smoke ‘em out” plan for muscle-growth, and it isn’t optimal or necessary.

The bottom-line here is: sessions can be short, and the gains still be sweet.

9. Thou Shalt Confuse Thy Muscles

We’ve all heard the speech, probably in an Austrian accent, where we are commanded to train with lots of variety, both within and between sessions, in order to “shock” our muscles into growing. The argument goes like this: Your body will seek comfort, normalcy, and homeostasis; so long as you can continue training in ways your body doesn’t expect, it will be forced to maximally adapt because it’s a new stimulus each time.

But let’s be clear: The only part of your body that can “expect” something to happen is your nervous system (the thing reading this article). Your muscles adapt to stimuli, and while throwing a new stimulus at your muscles every time you train will make your workouts hard, it won’t make them more effective.

The appeal to authority (“Well, Arnold did it!”) doesn’t help, since the claims here aren’t supported by any good science. What’s more, you can find examples of other successful bodybuilders with the opposite philosophy (like Ronnie Coleman, who famously did the same back routine for years). Ultimately, you shouldn’t concern yourself with their training philosophies, since they were taking “supplements” that you (probably) aren’t taking!

Never underestimate the power of consistency. Yes, variation is an important part of program design, but consistency and adherence are more important. If you think using lots of different exercises is fun and doable, then go for it. But if you only have an hour in the gym three times a week, focusing on a more meat-and-potatoes plan of a few core movements and accessories will take you a long, long way.




[1] Antonio J, Peacock CA, Ellerbroek A, et al. The effects of consuming a high protein diet (4.4g/kg/d) on body composition in resistance-trained individuals. Journal of the International Society of Sports Nutrition (2014). 11(19).

[2] Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition (2013). 11(20)

[3] Campbell B, Kreider RB, Ziegenfuss T, et al. International Society of Sports Nutrition position stand: protein and exercise (2007). Journal of the International Society of Sports Nutrition. 26(4): 8.

[4] Chow LS, Albright RC, Bigelow ML, et al. Mechanism of insulin’s anabolic effect on muscle: measurements of muscle protein synthesis and breakdown using aminoacyl-tRNA and other surrogate measures. Am J Physiol Endocrinol Metab (2006). 291(4): E729-736.

[5] Leveritt M, Abernethy PJ, Barry BK, et al. Concurrent strength training and endurance training. Sports Med (1999). 28(6): 413-427.

[6] Bell G, Syrotuik D, Socha T, et al. Effect of strength training and concurrent strength and endurance training on strength, testosterone, and cortisol. Journal of Strength & Conditioning Research (1997).

[7] Tsitkanou S, Spengos K, Stasinaki AN, et al. Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy. Scand J Med Sci Sports (2016). (Online publication ahead of print.)

[8] Schoenfeld BJ. The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength & Conditioning Research (2010). 24(10): 2857-2872.

[9] Cheung K, Hume PA, Maxwell L. Delayed onset muscle soreness: treatment strategies and performance factors. Sports Med (2003). 33(2): 145-164.

[10] Clarkson PM, Nosaka K, Braun B. Muscle function after exercise-induced muscle damage and rapid adaptation. Medicine and Science in Sports and Exercise (1992). 24(5): 512-520.

[11] Willardson JM. The application of training to failure in periodized multiple-set resistance training programs. Journal of Strength & Conditioning Research (2007). 21(2): 628-631.