- There are limitations to the maximum drug-free muscular potential models out there.
- It’s useful to be aware of them so that you don’t set yourself silly expectations and just get fat when bulking, but don’t allow them to place limiting beliefs on what you are capable of as you get close to these numbers.
- As fun as it would be, it is not possible to simply make a calculation to determine whether someone has taken steroids.
I am guilty of linking far too many people to a couple of articles on genetic muscular potential over the years, believing the formulas and calculations discussed within to be the definitive word on the subject of what a drug-free athlete can achieve.
They are not. This article is here to correct that.
MAXIMUM DRUG-FREE GENETIC MUSCULAR POTENTIAL MODELS
The models in question:
- Martin Berkhan’s Maximum Muscular Potential of Drug-Free Athletes calculation.
- Casey Butt’s Your Muscular Potential.
THE BERKHAN MODEL OF MAXIMUM DRUG-FREE GENETIC POTENTIAL
Though I’d highly recommend that you read the article, Martin’s formula for determining the maximum that a drug-free trainee will weigh when in “stage-shredded” condition (i.e. 5-6% body fat) is as follows:
(Height in cm – 98~102) = Bodyweight in kg.
This works out as follows:
- 173cm tall (5’8), your stage-shredded maximum will be ~75kg (165lbs).
- 178cm tall (5’10) your stage-shredded maximum will be ~80kg (176lbs).
- 183cm tall (6’0) your stage-shredded maximum will be ~85kg (187lbs).
- 188cm tall (6’2) your stage-shredded maximum will be ~90kg (198lbs).
While this is not a bad rule of thumb for estimating what a seriously hard-working trainee will achieve over a lifetime, it doesn’t take into account the genetically blessed exceptions to the rule. We’ll look at these exceptions now.
USING FFMI TO DETERMINE WHAT CAN BE ACHIEVED AS A NATURAL BODYBUILDER
Eric Helms wrote an excellent guest article for Alan Aragon’s Research Review recently, What can be achieved as a natural bodybuilder? Alan decided that it was such an important piece that he published it for free, and I’d encourage you to read it. (For those that won’t be bothered, from here to the table graphic below is a quick summary.)
Eric writes about some famous research from 1995, that looked at the fat-free mass index (FFMI) of steroid using and non-steroid using bodybuilders.
FFMI = fat-free mass in kg ÷ (height in meters)²
In the research 83 users, 74 nonusers FFMI were calculated and then compared. The average FFMI of the steroid users was ~25, of non-users it was ~22, and on the extreme ends a handful of non-users reached a FFMI of ~25.
To put that into more meaningful figures, the average height of the men in both groups was ~180cm (5’11), average body-fat percentage ~13%. The average weight of the steroid users was 92kg (202.5lbs), vs the non-users which was 82kg (180.5lbs).
The maximum FFMI of the non-user group was 25; for the steroid-using group it was 32.
From this research, it was suggested that the genetic ceiling for a natural trainee was a FFMI of around 25.
Comparison With The Berkhan Model
Here’s how the Berkhan model looks when the predicted figures from his model are converted to FFMI:
- 173cm (5’8), 75kg (165lbs) @5% = 71.25kg lean mass = 23.8 FFMI
- 178cm (5’10), 80kg (176lbs) @5% = 76kg lean mass = 24.0 FFMI
- 183cm (6’0), 85kg (187lbs) @5% = 80.75kg lean mass = 24.1 FFMI
- 188cm (6’2), ~90kg (198lbs) @5% = 85.5kg lean mass = 24.2 FFMI
We can see that the Berkhan model figures are lower, and the math works out to be ~6.5-8lbs (~3-3.5kg) lower than an FFMI of 25.
RESEARCH VS HISTORY
Eric then goes on to talk about the FFMI data of the Mr America winners from 1939-1959, spanning a period where steroids were almost certainly not used, to a time when they were, that was also discussed in that study.
Using Table 2 from Kouri et al, high scepticism is indicated by the winners in the green box, while moderate scepticism is indicated by the winners in the orange box. If we accept the 1939-1944 winners as natural, the average FFMI is 24.9, with the highest reported at 27.3. Applying moderate skepticism and accepting the 1939-1953 winners as natural, the average FFMI is 25.6, with the highest reported at 28.0. These means are not much different from the 1939-1959 group mean. In fact, the authors analysed the FFMI’s to determine if they were increasing over time. They noted: “there was no significant trend towards increased FFMI among the Mr. America winners over a 20-year span from 1939 to 1959.” Thus if drug use was occurring, perhaps it wasn’t frequent or effective enough to significantly affect the aggregate FFMI.
One thing worth mentioning, as it’s an issue I’m sure people will raise: ‘golden age’ bodybuilders usually carried more fat on stage than guys today (8-10% was more common than the 5-6% we expect now) which means their FFMIs were overstated a bit. On the flip side, awesome leg development wasn’t expected or desirable (compare Arnold’s legs to literally any pro BB today), which probably more than makes up for the difference. (i.e. if those guys were competing today, they’d probably have 3-4kg (~7-9lb) less fat, but at least 3-4kg more muscle on their legs and ass.)
CRITICISMS OF THE 25 FFMI GENETIC CEILING
1) There were guys with a FFMI over 25 that were almost certainly not on steroids. You can see from the table, one guy had a FFMI of 27.3, and another with a FFMI of 26.9, and if we lower our scepticism just a bit, we can take it all the way up to 28.
2) If we’re going to take a FFMI of 25 (or even 27.3 or 28) as the absolute limit of what’s attainable naturally, we would also have to assume that the most genetically elite people imaginable are included in that sample, which is not likely. Yes, those guys had physiques that were on par with the top drug-tested bodybuilders today (and some lifters of that era, including 26.9 FFMI Grimek, put up weights that are still very impressive by today’s standards), but lifting and physique sports have grown considerably since the ’40s and ’50s.
There is certainly the possibility that there are some people better suited for gaining muscle mass currently participating in bodybuilding and strength sports now, unless we can be sure that the bodybuilders from the ’30s and ’40s represent the absolute pinnacle of attainable human muscularity. However, the records in every other sport have progressed over time as better genetic specimens have entered the pool of competitors (I’d suggest The Sports Gene by David Epstein for more information), so I’m not sure why we’d assume levels of muscularity in drug-free bodybuilding would be any different.
3) We also have to assume that we’ve made no progress whatsoever in terms of training, nutrition, and supplementation. The cynic in me believes that we really haven’t made that much progress in terms of training for hypertrophy since a) periodization doesn’t seem to play much of a role, and b) the biggest determining factor for muscle growth just seems to be training hard and doing a bunch of hard sets, with other factors playing a much smaller role. Basically, getting big isn’t rocket science – it’s mostly about hard work.
However, I do think we’ve made some progress in terms of nutrition and supplementation. I mean, take something as basic as creatine – those guys didn’t have access to it unless they were eating a lot of raw red meat. Will it make a night-and-day difference? No. But it has been shown to pretty reliably help people gain a little more muscle mass.
It’s essential to keep these models and their limitations in mind when you plan your bulk. This helps to ground us in reality rather than fantasy land, ensuring that we don’t fall into the ‘dream bulk’ trap, gain a ton of fat, and waste a lot of time and effort dieting it off again.
The Casey Butt / Berkhan model calculations are probably best described as roughly an average of what’s attainable for most reasonably “blessed” people.
A FFMI of 25 is the number usually thrown around as the upper limit, even for someone with great genetics. But as we’ve seen, there are people who go beyond that.
We know that a FFMI of at least 27.3 is attainable naturally, and there it’s almost certain that there are people beyond this.
Add in some minor advancements in training, nutrition, and supplementation, along with some skepticism about whether the most elite of the elite genetically were competing in bodybuilding in the ’40s, and I think it’s pretty likely that some people can attain an FFMI in the 28s naturally.
Can many people? Absolutely not.
Can most people reach the more conservative limit of 25? Nope. Your genetics are your genetics, and some people were simply dealt a better hand than others.
But an FFMI over 25 definitely doesn’t automatically mean someone’s using drugs. And if you have rocketed your way up to the genetic limits calculated by the Berkhan model in your first few years of training, there’s every reason to believe you are one of the few that has the potential to go on and exceed it.
So, don’t limit yourself based on these formulas. The mind exerts a powerful effect on the body. Believe in yourself and have the mindset that you can, and you may just do so.
Here’s an excellent article by my friend Greg Nuckols over on Strongerbyscience.com on how to calculate YOUR Drug-Free Muscle and Strength Potential.
Thank you for reading.
Maximum Muscular Potential FAQ
Maximum muscular potential isn’t calculable. There are models that claim to be able to predict it, which I introduce in this article, but they have severe limitations. It’s essential to keep these models and their limitations in mind when you plan your bulk. This helps to ground us in reality rather than fantasy land, ensuring that we don’t fall into the ‘dream bulk’ trap, gain a ton of fat, and waste a lot of time and effort dieting it off again.
Yes. As you advance as a trainee, you can expect diminishing returns to your training efforts. You’ll make the best gains during the first year of serious training, as long as you get your nutrition strategy right also. See my free guide: The RippedBody Nutrition Setup Guide.
FFMI (Fat-Free Mass Index) measures the amount of muscle mass someone has relative to their height. In other words, it’s a way to quantify how jacked people are.
It is calculated as follows: FFMI = fat-free mass in kg ÷ (height in meters)²
You can use FFMI to estimate how close you are to your genetic potential, which can help inform your training decisions.
It’s not known for sure, but it may be a surface area to muscle volume ratio problem related to energy and oxygen delivery.
Once muscle fibers get too big, it may be too energetically costly to build more protein and maintain the fiber as it is, and there may be something telling the fiber that it’s no longer economical to build.
For example, when muscle fibers get too large, they can start having a problem with inorganic phosphate accumulation which can affect contractile function. Additionally, mitochondrial density tends to drop, capillary density per fiber tends to be maintained, but per unit of cross-sectional area tends to decrease. (Source: Stronger by Science Episode 20: Reading Research, the Placebo Diet, Muscle Memory, and Alex Kolliari-Turner)