Are Your Genetics Preventing You From Building Muscle?

Curious to know exactly just how jacked you can possibly get? Read this article and test out these formulas to get an idea of your genetic potential!

I’ve got some bad news…

You’re likely not as big as you think you are.

Let me rephrase that – you probably haven’t hit your genetic ceiling yet when it comes to lean mass accrual.

I know, I know, all your boys keep telling you that you’ve “gotten huge” but the mirror lies and egos get inflated quickly.

Not to mention, most people don’t know what they’re doing in the gym. Yeah sure, some happen to gain a little size but truth be told, they either got lucky, had a good mentor, or picked the right parents. However, to maximize genetic potential, you need to dial in a variety of factors and most don’t understand how all those variables fit together.

Now, I’m not going to delve into each of those individual factors as this short piece would quickly turn into a novel.

But, if you’re curious, I did touch on them briefly in this piece: How to Build Muscle: 5 Step Guide to Lean Gains

Instead, I want to provide some realistic guidelines on both muscle growth and genetic potential so that you can make informed decisions relative to your goals.

Let’s dive in…

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First Thing’s First

If you’ve read other literature on this subject then I’m sure you’ve seen terminology such as fat free mass index (FFMI), maximum muscular potential (MMP), or maybe even social media validation correlation (SMVC) – aka the number of likes and comments you’ll receive on each subsequent progress picture.

Just kidding about the last one, social media support is transient and overrated.

Related: 3 Unhealthy Habits Preventing You from Losing Fat

Anyways, if you’re like most folks, odds are you’re looking for someone to get to the point and drop all the sciencey mumbo jumbo. Normally I prefer to delve into the details because as I’ve said before, “some people just want the Kool-aid, other people want the recipe for the Kool-aid”.

However, for the scope of this article, I’m going to keep things brief and leave you with mostly practical takeaways. This topic is complex at best and mind boggling at worst, so I’ll spare you the details.

Can Your Genes Influence the Size of Your Jeans?

Genetics is the metaphorical trump card which everyone pulls to explain their lack of progress.

While fat loss is much less likely to be a genetic problem (side note: put away your Pubmed studies on the correlation between FTO genetic SNPS and obesogenic individuals, that’s another article for another time), differences in lean mass are much more likely to be genetically determined.

There are a variety of formulas one can use for determining their genetic potential but as I said at the start of this piece, let’s keep it simple for now.

Dr. Casey Butt’s Formula

Dr. Butt designed this formula after studying bodybuilders from the pre-steriod era of 1939-1959 where individuals typically exhibited FFMI’s above 25. A FFMI above 25 is thought by some to be a general indication of steroid use based upon the work of Kouri et al. in 1995.3

Estimated Normalized FFMIs of Mr. America Winners, 1939-1959

However, after analyzing anthropometric measurements from many of the previous Mr. America winners, it’s clear that a FFMI above 25 is indeed possible and occurred quite frequently before the popularization of steroids. After studying the data over the course of two decades, Dr. Butt devised his own formula utilizing height, ankle, and wrist circumference to predict muscular potential.

Future research went on to validate Dr. Butt’s conclusions as seen below:

“Wrist breadth is potentially the best discriminator of an association between frame size and amounts of fat and muscle, independent of stature. Broad wrists are negatively associated with total body fat and positively associated with fat free mass and vice versa”.1

“The variables which correlated most highly with actual frame size were body mass, ankle breadth, hand length and chest breadth, respectively. These variables were also positively correlated with fat-free mass (FFM)”. 2

If you want to calculate your own muscular potential, simply input your data below:

Dr Butts Muscular Potential Formula

Dr. Butts also proposed body part specific formulas which would (hypothetically) allow one to estimate the circumference of a genetically maximized muscle. Based upon your height, ankle, and wrist circumference values from above, your body part specific calculations (in inches) are as follows:

Butt's Maximum Muscular Potential per grouping

Martin Berkhan’s Formula

If you want an even simpler model, Martin Berkhan, founder of leangains proposed that one could hypothetically determine their “stage weight” (i.e. upper limit of body weight if in contest shape @4-5% body fat).

Now, given most people don’t walk around at 4-5% body fat (~12-14% for women), it’s safe to assume that you can add 5-10lbs to that hypothetical “upper limit”. This would realistically put you at 8-10% body fat as a male or 16-18% as a female – in other words, you’re still going to look “jacked” compared to 99% of other individuals walking the face of this earth.

Simply input your informtation and you’ll get a hypothetical (key word here) upper weight limit provided you have all aspects of training, nutrition, and lifestyle in order.

Berkhans Formula for Maximum Muscle Potential

At the end of the day, genetics can be a somewhat disheartening topic. You may feel like you’ve been dealt the short end of the stick and there’s no chance you’ll ever be able to actualize your dream physique. If that’s the case, you have 2 options:

  1. Accept the status quo and decide there’s no point in working hard because the “genetic deck” is already stacked against you.
  2. Realize that you may need to shift your mindset. Realize that you may need to tweak your goals from time to time. Realize that you may have to work harder than most. Realize that you may not progress at the same rate at others. Realize that at end of the day, this entire process is about the journey, not just the end goal.

As the ever-wise Greg Nuckols once said when discussing genetics and muscular potential:

“…maybe you’ve been at this for several years and you’re pretty sure you just didn’t pick the right parents to get super big and strong.  If that’s the case, my best advice for you is to simply work on finding ways to enjoy training more.  Find a style of training that’s simply fun and helps you stay excited about training, and shift from worrying about outcomes to focusing on enjoying the process.”

Measuring and Maximizing Muscle

When it comes to muscle growth and retention, many people hold common misconceptions as well accepted “science”. Just because your buddy claims he put on 20lbs of muscle in 4 months doesn’t mean he’s actually telling the truth, or that he understands what he’s talking about for that matter.

Related: 4 Things I Wish I Would’ve Known When I Started Training

Muscle growth is a metabolically costly and time consuming process. You don’t just wake up one day and realize you’ve gotten huge. If it were that easy, 90% of the people you see in the gym would actually look like they lift. But, given that’s not the case, you need to be realistic about this process, as well as your weekly, monthly, and yearly goals.

If we look at muscle growth on a macro scale (yearly), we can utilize a fairly simple but accurate model proposed by Lyle McDonald:

Years of Proper Training Potential Rate of Muscle Gain per Year
1 2lbs/month (20-25lbs total)
2 1lb/month (10-12lbs total)
3 0.5lbs/month (5-6lbs total)
4+ <0.5lbs/month (2-3lbs total)

Now, that may seem a bit disheartening to some, as you now realize that transformation stories of “50lbs of solid muscle in 10 months” are mostly bogus. Certainly, there may be some instances where an individual maximizes the upper end of potential growth.

But, in those situations, it’s typically because the individual may have started underweight or a significant portion of their accrued “weight” is actually stored glycogen, intracellular water concentrations, and food bulk in the GI tract.

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This can potentially account for 8-10 pounds over the course of a mass gain phase. So, while one may be lead to believe that they gain 30lbs of lean mass over the course of a year, it’s likely closer to 20-22lbs.

We typically see this to be the case when someone is in a deficit as well; someone may lose 6-10lbs in the first week and think they’re maintaining a massive caloric deficit when in actuality are just lowering glycogen levels and food bulk in the GI tract.

Alan Aragon proposed a similar model but broke it down on a meso scale (monthly) and allowed for a bit more individualization relative to frame size which is a good indicator of muscular potential.1

Training Experience Potential Rate of Muscle Gain per Month
Beginner 1-1.5% of total body weight
Intermediate 0.5-1% of total body weight
Advanced 0.25-0.5% of total body weight

Both models are simple but provide an excellent framework upon which to judge your current rate of muscular growth. Measure your bodyweight 3-4 times per week and see how the number changes. Slowly scale calories up or down relative to the current rate of change.

This is a lifelong journey, not a sprint. No one cares what kind of body composition change you incur if you can’t maintain it. Live for longevity.