Maximum Genetic Muscular Potential – The Models And Their Limitations

Ripped Body builder with muscle posing

Key points:

  • There are limitations to the maximum drug-free muscular potential models out there.
  • It’s useful to be aware of them, but you shouldn’t necessarily cap yourself at what these calculators would peg you as being capable of achieving.
  • As fun as it would be, it is not possible to simply make a calculation to determine whether someone is ‘roided to the gills or not.

The guy you see below is legendary Korean bodybuilder, Kim Jin Ho. This photo was taken of him at the Bodypower Pro show in Birmingham in May, a qualifier to get into the Mr Olympia competition 212lb division. Mr Olympia is bodybuilding at the highest level. The contestants are not tested for drug use. He is 5’4, and weighed 178lbs on that day. He won.

Is it possible that he is natural?

Muscular bodybuilding posing bicep flex

Four weeks ago when a mutual friend of ours insisted that he was, I scoffed at this idea. – Certain models of maximum muscular potential would suggest is he is significantly over his genetic limit. And though in fairness they weren’t developed for people of his stature (very short), he’s simply too far over it for him being natural to be plausible. Or is it?

I may now have changed my tune.

Why I’m Writing This Article Now

Ken and I have built our Japanese language sister site,, into the most popular fitness information site in Japan. We are highly trusted, but with such a big readership I feel there is a big burden of responsibility on our shoulders to get things right.

It came to my attention recently that I had screwed up – we released a translation of an article on genetic muscular potential that left people open to steroid accusations as we hadn’t discussed the limitations. In honesty, I wasn’t aware of them until recently but I should have been more careful. We fixed the error a couple of weeks back by providing an extensive update, and influential industry friends here kindly shared the shit out of the updated version once again on social media.

Now, when it comes to my English readers 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.

There are some historical exceptions and limitations to the models that I’d like to discuss. And we’ll finish with our man Mr Kim as an example.

Maximum Drug-free Genetic Muscular Potential Models

The Models In Question:

Lyle McDonald has made an excellent analysis of both in his own article on genetic potential and pretty much concludes that when glycogen and water weight are taken into account, that they come out at roughly the same level regarding maximum muscular potential. I’m not going to go into more detail on it, you can read that here.

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 centimetres – 98-102) = Body weight in kilos.

This is likely to be the formula that my Facebook chum Gregory O’Gallagher, at the ripe old age of 23, has used to conclude that he is, “pretty close to the brink of what is achievable naturally for my height.“. He really needs to reel his neck in (and trust DEXA scans less) as he’s doing himself a grave injustice here by placing limiting beliefs on himself, which is something I’ll come to later.

Anyway, if you’re,

  • 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 a 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.

Mr America Winner FFMIs - 1939-1959

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.

Applying the Formula – An Example Case

Kim Jun Ho - Bodypower Pro 2015 Lineup - iPhone Snap

So let’s go back to Mr Kim Jin Ho. He was on stage at 178lbs (~81kg), ~5’4 (163cm) in height.

  • This puts him with a FFMI of 29.5, with an adjusted (for height) FFMI of 28.4, which is just 1.1 points above the biggest of the Mr America Winners of the 1939-1944 (almost certainly steroid-free) period.
  • He is 46, so he has a very long training history, and many years to potentially put on muscle.
  • He had a normal voice, his jaw/forehead looked normal, and he doesn’t have the distended gut. (So, no hallmarks of human growth hormone use.)
  • Shredded, but didn’t have the overpowering traps/delts, and no acne marks on his back. (So, none of those obvious signs of AAS use.)

So is he natural?

Well, I wouldn’t bet my life savings on it, but it’s certainly possible. Regardless, this misses the point of this article…

The Point Of The Article

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 in all likelihood, 28.0. Add in some minor advancements in training, nutrition, and supplementation, along with some scepticism 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 a 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 a 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 over the body. Believe in yourself and have the mindset that you can, and you may just do so.

Update 30th Sept. 2015: Here’s an excellent article by Greg Nuckols over on on how to calculate YOUR Drug-Free Muscle and Strength Potential.


Thank you for reading. 

Productive discussion, correcting errors in my logic, etc. are welcomed in the comments. Accusations or name calling are not, and will be deleted without hesitation. I just can’t be bothered with it.

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About the Author

Andy Morgan

I am the founder of, this is my sincere effort to build the best nutrition and training guides on the internet. Some readers hire me to coach them, which I've been doing online, via email, for the last six years. If you're interested in individualized, one-on-one nutrition and training coaching to help you crush your physique goals, let's start the conversation.

62 Comments on “Maximum Genetic Muscular Potential – The Models And Their Limitations”

  1. Carl Juneau, PhD says:

    Great post! Been a while since I’ve seen anyone add to this discussion in a meaningful way. I’ll share in this week’s bodybuilding science review newsletter.


    1. Thank you, Carl. 🙂

  2. Hos Delgado says:

    Andy, as far as I know, the very first known reference to anabolic steroids in a bodybuilding magazine is dated 1938 – in a magazine called Strength and Health, there is a letter addressed to the editor of Strength and Health. So there is a destinct possibility that in the late 40’s there might have been some experimentation kept strictly between the elite bodybuilders of the time.

    Ref: Hoberman JM, Yesalis CE (1995). “The history of synthetic testosterone”. Scientific American 272 (2): 76–81. doi:10.1038/scientificamerican0295-76. PMID 7817189.

  3. Matthias Flehl says:

    Are there studies or better formulas out there related to muscle growth respecting the age?

    I mean there should be a tremendious difference in building muscles between a joung boy starting with 15 years and a men starting with 30 or 40 or 60 years when they work out in similar intensity and all other conditions like nutrition, sleep and stress are the same.

    1. Hi Matthias.

      I recall the one (but can’t find the link), and I believed it showed that adaptations to training (muscle growth) get less as we age. The real question is whether this matters at all, and I’d say no. You’re not getting any younger, so it’s pointless worrying that you’re not getting the gains you would have. Higher lean body mass levels are linked with longevity and quality of life in old age (being able to sit and then stand from the toilet by yourself for longer) and studies show time and time again the positive effects of strength training in the elderly.

      Let’s do a little more mental masturbation here. At 15 we will take advantage of the growth spurt, so let’s set that aside for a moment and consider 20-60 instead. The difference we’re talking about is a gradual reduction in recovery capacity, more injury considerations, and an increase in the lower threshold of protein intake in one sitting for MPS to take place (~20g – ~35g, meaning fewer meals with more protein per sitting are better, or just keeping protein intake high a good idea). The latter is irrelevant outside of extremely high meal frequencies or low protein intake, the injury part we have no control over (what’s done is done), so we get to the first item – recovery capacity.

      Recovery capacity and adaptions to training will be different in different people. Some blessed, some not, most of us average. Forget that. Will YOU get the same training effect, all things being equal at 50 as you would 20? Not quite.

      However, all things aren’t equal. You probably sleep better now, have access to better information, training modalities, money (should you need to see a trainer to guide you around any injuries) and your quality of diet is probably higher. You probably have a lot more commitments which make hitting the gym harder too… Well, I guess it’s swings and roundabouts.

  4. George says:

    I also forgot to give a massive thank you as I was originally 90kg and managed to lose 6kg using your cutting calculator and principles leaned from your site over a 4 month period. (Intermittent fasting and carb cycling). I had the added bonus of some abs for the first time in my life too 😉

    1. Awesome, really happy to read this George. Keep it up. 🙂

  5. George says:

    I’m sorry but I refuse to believe these figures. I’ve been working out on and off for a few years but only serioisly in the past year. I’m 5’10 and 86kg with about 10% Bf (Jackson pollock method) . I believe I am still a beginner in terms of lifting weight as my squat is only 110kg and benching 90kg on the 5×5 program. I’m still gaining strength and size each month. I have always been a bit heaver than other people my size and build even before starting working out but I have small wrists and ankles and am not big boned. Anyway these calculations mean that I am at the upper end of my limits which is totally ridiculous!

    1. Absolutely George. You’re an outlier, didn’t say there weren’t any. Ignore this article.

  6. Trent says:

    Hi Andy,
    Many of the pages I found for adjusted FFMI added a coefficient for height; ie adjusted FFMI = FFMI + 6 x (height – 1.8).

    I just had a read of the pubmed extract, and the ratio is REVERSED! 🙂

    That is “We then added a slight correction of 6.3 x (1.80 m – height) to normalize these values to the height of a 1.8-m man”.

    So the formulae for adjusted FFMI = LBM/(Height^2) + 6.3 x (1.8-Height).

    In my case, LBM = 92kg and Height = 1.91m
    therefore adjusted FFMI = 92/1.91^2 + 6.3 x (1.8-1.91)
    = 24.52

    much more reasonable than the suggested 26 which occurred when the coefficient ended up with a positive value adjustment.


    Kind Regards,


    1. Cool glad you found it Trent.

    2. Nathan says:

      Trent, in the study text it’s actually 6.1, where the abstract 6.3 (likely a typo). Every online calculator I’ve found appears to get this wrong. Based on how I’m reading the study, the taller people had a higher FFMI, even with less muscle development, so their adjusted formula reduces the number for tall people and increases it for short people. They explain this by pointing out that taller people are usually also wider/thicker, and the standard FFMI formula is 2-dimensional, not 3-dimensional. I’d love to know where all this went wrong. Since most online calculators seem to use the same source code, one mistake seems to have been copied quite a number of times.

  7. Trent says:

    Thanks Andy,
    I note though, the adjusted FFMI suggests adding to the index for heights above 1.8m.. ie adjusted is FFMI + 6*(height-1.8).. In my case, this takes my current 25 up to 26…

    I’ll have a DEXA done in a couple of weeks to make sure my numbers on BF% & LBM are correct… but i’m unlikely to have bf >12%, being i’m only 13 weeks post comp (INBA physique) and haven’t been binging or on a massive surplus….

    Has anyone ever calculated a formulae for muscle mass index, ie maximum genetic potential of muscle mass based on height, size, bone density etc?

    Perhaps this will be a good question for Eric Helms (he’s co-presenting camps with Layne Norton in Sydney this April, I’m lucky enough to have gotten a place to attend)..

    Thanks again.


  8. Trent says:

    HI Andy,
    Nice article and a good read in the comments too – it’s great to see your engagement with your readers and fans!

    Anyway, on the FFMI; is there a way to “adjust for height” for tall blokes?

    I’m 191cm, and run a LBM of 92kg at the moment; that’s a FFMI of 25.2..
    100% natty, 35 years old and training for only 3 years.

    I wouldn’t call myself genetically gifted, growing up as a very skinny, lanky kid & teen.. Whilst my 3 years of lifting has seen me reach half-decent lift 1RM results (Sq 185kg, Dead 245kg, Bench 120kg)..

    I still have a good number of years ahead of me and still have room to grow.

    I think part of the problem with the formulae is no coefficient for bone density/mass – especially as a taller person further builds on this through compound lifting..

    Keep up the great work – btw your page helped me with my first introduction to training back 3 years ago.. Links from Fitocracy brought me to your site, and I used your training recommendations in hand with IF to hit sub 9% for the first time in 2013..

    1. Thanks Trent, glad the site has been so helpful to you.
      – Yes, this is called an adjusted FFMI. Just google it and you’ll see guides come up.

  9. Victor says:

    I don’t believe the guy in the example is or could be natural.
    All the point made in this article, as well as in the Eric Helms one, is based in the assumption that the FFMI of the Mr Americas is remotley acurate which i don’t think is the case.
    Look at the FFMI of John Grimek: it goes from 24 to 26.9 in the timespam of one year. Assuming he is 1,75 tall, he would have gained 9kg (20lbs) of lean mass in that time. 9kg of muscle in one year is a great acomplishment for a begginer, it’s just impossible to put that much in one year (or at all) on top of an already Mr America winning physique.
    Also, if you look at photos of these guys, for example Steeve Reeves and Jack Delinger side by side (, they look they have the same degree of muscularity. There’s no way one FFMI is 23 and the other 28.
    These FFMI of former Mr Americas are completely urreliable to draw any valid conclusion.
    A FFMI of 25 is actually great in real life (outside the internet). Its someone with very good genetics who trained hard for years, someone that look big to most people and will be acused of juicing frequently. Most wont reach a FFMI of 25 naturally. There should be some freaks capable of reaching 26, but more than that? I don’t buy into it, specially considering how financially and professionay rewarding is to be a fake natural bodybuilder, trainer or youtuber nowadays.

    I agree with Casey Butt when he says : “The truth is 20 pounds of real, permanent muscle would transform your body. Most magazines and websites make it seem like 20 pounds of muscle is nothing …like your grandmother could gain that much. The reality is, if you gain 20 pounds of muscle this year everyone will notice and they’ll probably whisper behind your back that you’re on steroids – my friends did and I didn’t gain nearly that much in any one year. Gain 30 pounds of muscle (above your normal, healthy adult weight) and you’ll be carrying as much muscle as a world-class drug-free bodybuilder.”

    1. Victor, thanks for commenting. I’ll reply in order.

      1. Re: Grimek. He made a jump from 24 to 26.9 FFMI in a single year, 1940-1941 – the years when we’re fairly sure steroids weren’t available. Essentially the question is, “What possible explanations are there for the 2.9 jump in FFMI (~20.7lbs in stage weight difference) in a single year, other than steroid use?”

      Well, back then people were less consistent with individual stage condition (how shredded they were), and the levels of conditioning expected were not what they are now. A less lean, more hydrated and glycogen filled Grimek on stage, with a year of solid training behind him, could easily explain the 20lb increase, and perhaps overall size was more important than being leaner back then, to a point.

      2. An interesting point. I have assumed that the FFMI figures are correct, for lack of choice really. I would’t try and read too much into a single photo, with different angles.

      3. “There should be some freaks capable of reaching 26, but more than that? I don’t buy into it.” – Fair enough, I disagree though. (The math of why I think it’s possible is covered in the article.) There are more people in the sport now, so the chances of one of the few people in the world with potential to reach 26+ starting it are higher. And though the financial rewards of becoming a fake natty are going to overpower a lot of people’s morals, some people won’t do it simply out of principle, knowing they have to look at themselves in the mirror each day.

      – A man walks out of the coffee shop leaving his briefcase behind. You look to see if you can find a name on it, and it pops open, revealing $10mil in cash inside. Now, a lot of people are going to silently take the money and disappear. – Not everyone though.

      4. I absolutely agree with your last paragraph.

      1. Victor says:

        Andy, while i don’t agree completely i can see tour points.

        You are right about the variability of the conditioning these guys presented at contest day. The carb intake and short use of very high volume in the weeks prior to competition sure could have an effect on lean mass. But 20lbs would be more what a fighter varies in lean mass with weight-in dehydratation. Still possible, just not likely in my opinion.
        It’s just that one would expect that the top genetic gifted individuals, with no access to drugs, training with the same goal, would end up somewhat in the same ballpark of muscle mass. But the values vary so much, even in the same individual, that makes me very suspicious of the acuraccy of the measurements. Also because i don’t see that crazy variation in old photos or videos. But i could be wrong.

        Let just forget the number aspect for a moment. The old school guys had a very different look, this is not only a matter of body fat percentage, you didn’t see the “full muscle”, “thin skin” pumped look. Look at Clancy Ross: Acording to the chart, his FFMI is over 26, even then doesnt have “that look”.

        I agree that there are many individuals that refuse to pull the fake natty routine due to their morals. Unfortunetly these guys are often the guys who have their advice discredited as trainers because they are being compared to drug assisted standards of muscle mass, or are the guys losing a natural bodybuilding competition because they are competing against users.

        Just as a closing thought: I live in Brazil, fitness is a big thing here , lots of gyms, so a very large talent pool. But at the same time, while selling steroids is a crime here, the possession is not, and its not as much seem as a morally reproved thing as in some other countries, and even some supplement sponsored competitors admit using. So here people talk more openly about it, and people are more realistic about what can and can’t be achived naturally. Its interesting that here you almost don’t see these huge naturals genetic freaks that appear so frequently in the US.

  10. Fest says:

    Hey, sorry for offtopic but could you tell me what comment system are you using? Btw. great blog 🙂

    1. It’s just what comes as standard with WordPress.

  11. Ark says:

    Hi Andy,

    I couldn’t find an option to leave a comment for the latest complete diet guide with pdf. Just want to thank you hugely!!
    All my friends are abusing printers now to get it on paper:) And this is Super Cool!

    Thanks again. Your web site is getting into perfection inevitably:)


    P.S. Are you planing to do something similar for the training guide by any chance?

    1. Haha, awesome! 😀
      Not with the training guide. We recently did a translation of Eric Helms Youtube training pyramid series for the Japanese audience. Ken did an awesome job and I was planning on translating it back into a version for RippedBody with Eric’s permission, but he said he plans on releasing his own e-book version, so out of respect I said that I wouldn’t do it. I may end up helping him write it though as the layout and ordering is already largely done (and was a big task when taking it from video to text.)

      None of this will be happening any time soon though, so I’d check out Eric Helms video series for now.

      1. Ark says:

        Will do! Please keep us posted when Eric”s text version will come out!
        Hope you will be enjoying the rest of the summer!


        1. Cheers, will do, and you too Ark.

  12. Seth says:

    Andy, thanks for the ideas. I am going to be starting my bulk on August 1, so I will be taking in more food for sure, and will change up my workout to see if I can find something that will work better during this bulk. Since I was on my cut for summer, I have just focused on going heavy, but I think I kept volume to high when I should not have. I guess for me, it just takes about 1.5 – 2 hours of lifting before I start feeling fatigued, or like I am hitting a wall…..

  13. Seth says:

    Hey Andy,
    So Kim you are saying is natural, even w/ the amt. of definition he has? I mean those quads are insane.

    I guess for me, I am just getting to the point where I am disheartened/frustrated.
    I am 6’1″ (lanky, very small wrists and ankles), been lifting since I was 17 yrs old, I am 37 now.
    I did a lot of basketball, volleyball and stuff in my 20’s and late teens.
    And since 2013, I have started IF as well as really giving my workout sessions 100% energy and focus.
    But it just seems like I will never get to ~180 lbs, w/ <8% BF
    And my high end weight lifting seems to be limited by my joints at this point. Once I start going heavy, then I start feeling it in my joints.

    Looking at some posts by Gregory, perhaps I need to back off my workouts some…
    He seems to do 3x/week.

    Worth a try I guess.

    1. Seth, thanks for the comment and questions.
      “So Kim you are saying is natural…?”
      – Nope, I’m saying it is within the realm of possibility that he is.
      Looking at some posts by Gregory, perhaps I need to back off my workouts some…
      He seems to do 3x/week.

      – It’s good to look at what some else is doing and draw inspiration from it, but you want to get to a point where you know how to find tune your own training. Joints ache? Options: Eat more / reduce training load (use lighter weights, higher rep sets, but maintain volume) / reduce volume or frequency. Change one variable at a time, so you can effectively gauge efficacy, then fine tune from there.

  14. dan says:

    hi andy. just wondered do you just give clients cals and macros to follow or specific meal plans? also still a little confused on progressive overload. if load increases but volume decreases is that overload? many thanks

    1. Hi Dan, thanks for the questions.
      1. Macro targets, as that is simply a more accurate way of counting calories. More on how I do it here:
      How To Count Macros – A More Flexible Approach
      2. Yes and no. Check out this excellent video by Eric Helms as that will explain it for you. I plan on putting together an article based around it in the coming month.

  15. Da Cruz says:

    Hey andy. How should my macros look if i choose eating maintence?

    If my i need 2k “calories for coma” x the factor ( 1.5 for example ) and also eating 20% plus in the days i train and 20% less in the days i rest. How many protein and fat should i eat? i know the rules for the macros on cutting and bulking but not for maintence.

    Can you tell me? and things i’ve said are right?

    Thanks and great article!

  16. Mario says:

    Awesome work Andy, one of the best articles I’ve read on the topic! In the past I’ve mainly used Casey Butt’s calculator as made some great points in his “Your Muscular Potential” book.

  17. Tim says:

    I always wondered why these so-called natural genetic freaks don’t enter drug tested shows and blast everyone off the stage. They always seem to claim natural but stay in non-tested shows?
    Also if you really delve into Casey Butts study and work out your numbers you’ll be surprised at the actual size he talks about. It’s actually not a limitation but a target that few will ever achieve.

    1. Hi Tim, thanks for the comments. As for your question, well, either because they know they’ll win (thus it takes the fun out of it), or they know they’ll get caught. Just note, there are ways to still use drugs for part of the year and get around tests. Even in the different ‘tested’ divisions/competitions you’ll see that the FFMIs of the winners scale with how strict the testing is. Eric Helms had a video on that actually somewhere, though I don’t seem to have saved the link.

  18. Andy,

    I enjoyed the article, but there are a few points where I am confused or skeptical.

    1) As far as I can tell, synthetic testosterone was being tested in humans in 1937, so why are we so certain that it wasn’t being used by bodybuilders in the early 1940s?

    2) John Grimek gained 20lbs of LBM between 1940 and 1941 after already being advanced enough to win Mr. America? His 1941 FFMI is also the first one to cross the 25 barrier. I’m inclined to think that his improvement there is suggestive of someone who has started taking testosterone.

    3) You make the point that records in other sports have consistently improved with time, but I think that a lot of that is due to improvements in equipment and the increasing prevalence of PEDs.

    1. Hi Shem, thanks for the questions.
      1. Read Eric Helms article, he has this specific thing covered.
      2. I agree, this is a weird outlier or typo, or it could have implications for your point above.
      3. I’d agree that this is related.

      1. Shem, I’ve had more of a think about this point regarding Grimek.

        He made a jump from 24 to 26.9 FFMI in a single year, 1940-1941 – the years when we’re fairly sure steroids weren’t available. Essentially the question is, “What possible explanations are there for the 2.9 jump in FFMI (~20.7lbs in stage weight difference) in a single year, other than steroid use?”

        Well, back then people were less consistent with individual stage condition (how shredded they were), and the levels of conditioning expected were not what they are now. A less lean, more hydrated and glycogen filled Grimek on stage, with a year of solid training behind him, could easily explain the 20lb increase, and perhaps overall size was more important than being leaner back then, to a point.

  19. Excellent article Andy!

  20. Ryan Saplan says:

    Great article Andy. This is the first article I’ve read of yours. I got pointed here from a PTDC email. Great stuff.

    1. Cheers Ryan! Welcome. 🙂

  21. Chris says:

    Hey! I completely agree with your discussion pertaining to absolute upper limits. We may have improved in some fields, the genetic pool is larger (finally a black powerlifter. and he is not shabby: ) – d´accord.

    But I think your perception or wording is still distorted statistically: We have no evidence-based obligation to encourage ppl to “look or believe that they can reach beyond an 25 FFMI” – its has no practical sense: Because youre talking as if an FFMI of 25 or beyond was feasible for 5% of the population. Or 1%. It is not. It rather is for 0.1%, maybe 0.01% or 0.001% (yes, thats 1 in 10,000 and 100,000 people, respectively). And those who can indeed surpass that are people that run around jacked just by hitting end of puberty or a couple of weeks after picking up some weights. Just as Greg Nuckols here did in the strength department, outperforming a lot of hard-training people with shitty-to-none specific training (albeit hard work) at his 16th (or was it 15th?) birthday. So theyll NOTICE they are something very, very, special – just like you couldve been a semi-blind soccer scout experiencing 16year-old Messi playing: you wouldnt have overseen him. They dont need this information. And the others? Well, they WILL all cap at 25 or lower. “they” meaning 99.9 to 99.999 % of the population. That means for me: you. You ALL.

    Youre not even American, but still it has a slight smell of: “Think there are no boundaries – and there will be none!”. All right, yes we know motivation is very important. But you know, we dont need it delivered that way: I think your audience
    a) have a slightly optimistic and unrealistic view of their capabilites anyway, as has every non-depressed person and
    b) we´re an intelligent audience because we read a highly intelligent author, you.

    And we have a great website to reach our capabilities: (Sorry Greg, can only brown-nose your website on your website. 🙂 ).

    1. Chris, thanks for the comments. First time? Anyway, a good start and some interesting points.

      I think that your point b works to counter a.
      “I think your audience have a slightly optimistic and unrealistic view of their capabilities anyway…”
      – I’d say that this is accurate for 95% of the fitness webshites out there, but the readers of this site have a higher knowledge level and more realistic view on things.


      Because the information here is very detailed and thorough. It’s what people need to be successful, but it’s not the short cut that people are hoping for when they start out. Thus, the detailed guides act as a nice audience filter – those looking for a quick fix or have unrealistic expectations don’t bother to stick around if they stumble on it, but those that have been jerked around for years feel like that have found a home when they find it and read the level of detail and lack of bullshit in the guides.

      “You’re not even American, but still it has a slight smell of: ‘Think there are no boundaries – and there will be none!'”
      Have a re-read of the closing section of the article. I don’t think that the wording is distorted, think it’s quite clear. The problem is that a small minority of people are always going to read into things that haven’t been written to suit their own preconceptions.

      Note the conversation between Gregory O’Gallagher and I (see older comment), the Facebook chat. – It’s quite clear that despite reading this he was happy to conclude that he was done with his genetic potential at 23. And it took me 30 minutes in the Facebook chat to get him to see it any other way. Some people really need a kick up the arse and to believe in themselves more. Because belief really does affect outcomes:

      ‘Strong’ is Determined by the Size of Your Pond

      Bear in mind what I’ve said and let me know if there is anything you feel strongly about. – Imagine that I were to give you the editorial keys to the kingdom here, what sentences would you change, and exactly what words would you change them to? I’m not promising to change things, but I do take comment feedback into consideration when editing and improving the site.

      1. Chris says:

        Hi Andy!

        Thanks for answering. Yes, I posted for the 1st time on your site. Have read a lot of it – great info. Its… I dont see the need in general to address a problem only 1:1,000 people like Gregory affects. On a website directed to an, albeit filtreed and intelligent, but still general audience. To be honest, I really didnt think someone who is close to a 25 FFMI stops trying to improve because he deems it impossible to cross that boundary – even if he currently is say at 24.5 and still improving. So yes, you may have saved Gregory and similar people from underachieving by this article.

        In the signal-detection paradigm, such an article minimizes false negatives – people like Gregory – while raising the number of false positives – ppl who keep on trying to cross 25 even if its worthless for them. Granted, nothing really bad happens if they try and fail. But given the clear statistics – 1:1000 vs 999:1000 – this at least for me is an easy cost-benefit decision not to bother about the 1:1000 and not to give false hopes to the 999:1000.

        Maybe an editorial suggestion is: you could put these numbers in the arcticle to clarify the scope were talking about with this “problem” of not trying to cross 25. They may be off, I dont know of any in the research (have they done that?), but given the frequency of Mr. O participants divided by strength training indivudals, they might be even optimistic.

        On a similar topic, I strongly think there should be better research concerning muscular and strength potential. All the studies seriously lack in one or the other department, be it ecological validity, statistics. This is prominent in other baseline numbers as well: The only “strength standards” that are out there, are those Kilgore/Rippetoe tables that are copied and put on various websites. Well, its Kilgore/Rippetoes experience (dont even know if they even did proper studies) with Texan high school and college boys entering the Wichita Falls gym. Add to that Rippetoes exaggerations what his trainees are up to within these time frames – and thats the only “statistics” we have about long-term training strength results in free weight exercises!
        Thanks again Andy for your excellent work (even if I dont see the need for this article 🙂 ), I have learned a lot here!

        Sorry, I mixed up Gregorys FFMI. So Gregorys problem didnt even need this article as he wasnt close to 25 – but quite off with 23. Thats exactly what I meant: There are extremely few ppl out there who are near (e.g. 24,7) the 25 mark. (Most of them who claim they are, miscalculated their body features or dont fall within the ranges the researches defined for application of that cutoff. See the comment section of Lyle McDonalds article Andy cites.) So Gregory and others may need a general encouragement – but there is no need to discuss the validity of the 25 mark for 999 out of 1000 people.

        1. Chris, thanks for the replies.
          “So Gregory and others may need a general encouragement – but there is no need to discuss the validity of the 25 mark for 999 out of 1000 people.”
          Actually, I believe there is.

          I feel genuinely sorry for the handful of truly genetically blessed, exceptionally hard working natural trainees in the world that have refused to use drugs, and yet as they have crossed the barrier of what is deemed possible by these formulas, are immediately cast as drug users.

          The most fundamental purpose of this article is to help out these guys by pointing out that there are exceptions to the models.

          I can only imagine how they feel to be put in the same camp as the fake naturals that surround them. And even though this article may help more of those fake natties hide their drug use than it does these natural guys, that’s just how it is for now, until genetic testing comes around.

          The 1 in 1000 suggestion sounds reasonable, if not optimistic. But as it’s not a genuine statistic, and we can’t put numbers in the article, I won’t include it. Gotta stick to the facts here. I appreciate your thoughts though.

    2. Hey Chris. I thought the ending was pretty clear about what the majority of people can expect.

      “I think it’s pretty likely that some people can attain a 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 a FFMI over 25 definitely doesn’t automatically mean someone’s using drugs.”

      It addresses both what you can most likely expect (the middle of the bell curve – somewhere below 25), but also what you can expect to see from others (the tails of the bell curve, likely somewhere quite a bit beyond 25).

  22. dan (dwfitness) says:

    hi andy, interesting article, i will be a little more open minded from now on. the point on traps/shoulder development for aas users is interesting. I thought that was just a myth, do you know of any studies that support the theory?

  23. […] refers will differ depending on various conditions such as the athlete’s training experience, genetic potential, nutrition, sleep, and rest, etc. For example, a beginner may be able to add 2.5kg to their squat […]

  24. […] Related: Maximum Genetic Muscular Potential – The Models And Their Limitations […]

  25. […] your physique after dieting. If you are looking to improve and haven’t reached your likely genetic ceiling then this guidance is for […]

  26. […] there are outliers, the best industry estimates of genetic maximum muscular potential of drug-free trainees suggest that the maximum a ‘reasonably genetically blessed’ stage competitor can expect […]

  27. Thanks to Gregory for letting me share this Facebook chat. I think there are some good points made.

    Gregory O’Gallagher
    Could you edit my reference in your maximum muscular potential article? Never said I hit my genetic potential. Only that I was near it. Which is still the case even if 7.7% was actually 9 or 10.

    Andy Morgan
    Was intended as a friendly jovial jab, nothing more than that.
    Permission to explain?

    Gregory O’Gallagher

    Andy Morgan
    I saw a status update a while back:
    “Pretty much the brink of what is achievable naturally for my height.”
    But now that I spent 20 minutes looking back through your wall to see if I got things wrong, I saw that you made an edit later that day so I’ve edited the post now above.

    Anyway, point is, I didn’t see your edit. But I did see the post later that day starting: “I think a huge mistake a lot of the best natural fitness models have made is that they get to a point where they look really good! But it’s never enough for them and they want to keep growing (past their natural limits).”

    So onto the purpose of why I put you in the article:
    You’ve grown exceptionally well given your age (I got it wrong I see, you’re a little younger than 27 right? Is it 25?) and you still have a lot more potential to grow. But you seem to believe that you don’t, which is incorrect. You could be huuuuge if you believe in yourself and keep pushing.

    Gregory O’Gallagher
    Cool thanks for clearing that up. I kinda summarize my stance on that in this post. . I like my current size. Not too worried about getting a lot bigger.

    Andy Morgan
    And you’re 24 was it? I see you saying that you mentioned your business goals were finished a year early.

    Gregory O’Gallagher
    24 in September. But I’ve been training since 14

    Andy Morgan
    I did some math for you. A gain of 9lbs would bring you to a FFMI of 25. (If we trust the DEXA, but I reckon you’re more like 9-10% though and you just look leaner cause you carry a lot of muscle.)
    That would add 2-4lbs.
    And, I reckon you could go way past 25, if you wanted to of course. But I agree, is it worth the effort with all the decreasing returns on your time investment? – Possibly not.

    Gregory O’Gallagher
    Yeah I believe 9 lbs
    But your last statement is exactly that
    I’m not a physique competitor
    Just trying to maintain a great physique that I think inspires people

    Andy Morgan
    ^ I hear you.

    Gregory O’Gallagher
    I think some followers get discouraged if we appear to be too big or jacked or even lean…
    Since it doesn’t seem attainable to them
    And that’s one of my angles. Enjoying fitness and letting fitness be a secondary goal in life while you conquer shit

    Andy Morgan
    Fair enough then.

    The points to be careful about are probably two-fold:
    1. Don’t allow yourself to believe that you’re done, cause if you do, it will actually limit your gains in the gym from now on. Great link at the bottom of the post about that.
    2. Careful of letting people believe that you would need to take drugs to be bigger – cause you put limits on them also. Perhaps better to just say that you’ve made a conscious decision to just maintain a nice balance between training/work and life, rather than putting in all the incremental effort (gym time mainly, due to the increase of volume in the gym needed to drive adaptations from here) with smaller rewards that you don’t really care about as you’re not a physique competitor, and don’t want to look too far from your target demographic.

    Gregory O’Gallagher
    Yeah gotta understand my mindset
    I’m different
    I push like a mother f*****.
    Saying Im happy with where I’m at allows me to enjoy the process
    I still PR like crazy
    And nah… If that’s the impression you’re getting. You have completely missed what I’m doing
    I’m not a bodybuilding coach

    Andy Morgan
    If you’re PRing then it’s likely you’re growing.

    Gregory O’Gallagher
    People seem to think they can get huge naturally.. Looking at all these fake Barrie’s

    Andy Morgan
    Point two is in reference to what you wrote on the Instagram image.

    Gregory O’Gallagher
    That f**** with their concept

    Andy Morgan
    I’d agree, there is a problem with fake natties.

    Gregory O’Gallagher

    Andy Morgan
    And on balance, more people have an overinflated view of what they can achieve than those that are the other way round.

    Gregory O’Gallagher
    But yeah I hear you

    Andy Morgan
    That article is only targeted at the latter guys though – I’m hoping to free their mindsets.
    Guys that have inflated views of what they can achieve won’t be reading my stuff at all.
    Right, I have a proposal.

    Gregory O’Gallagher
    But yeah best not to impose limits at all
    And just see how far one can go
    But then not getting discouraged

  28. Tom Øberg Framnes says:

    Exceptional as always Andy. Always looking forward to reading your next installments, and also appreciate the honesty as too many, are too biased and stubborn to admit the error of their previous ways.

    I remember when I first contacted you back in 2013, when I was first getting into leangains/IF and i remember i got declined with personal consultation, as my expectations and goals was beyond naive to achieve at a first time setting.( wanted to achieve 5% sustainable bodyfat year round like Martin Berkhan) I couldn’t see it then, but now three years later after failing/prevailing I know now what you meant Andy. And I’m happy that you declined me, because it made me figure out things that I honestly think, no, I know, that I needed to figure out for myself.

    It made me into a better athlete, instructor and trainer and I just wanted to let you know, that I’m as well neither too stubborn to admit the errors of my way.

    I ended up making all the wrongs that you mention in your articles, everything from crash dieting, implementing too low calories/ too long fasts, binge and fast type of approaches etc. until I decided to back to the drawing board. Reset, and start back on it. Ended being on a one year bulk throughout 2014. Managed to put on 6 kgs of mass, but as many do on their bulk, I probably gained a bit too much fat lol. I see that now, and have learned from it respectively.

    I’m now at the end of my second cut, started out at around 20 percent BF 2 January. My goal hasn’t changed lol, still want to get as sustainably lean as possible, but this time I’ve done it correctly. Slow but steady. Moderate deficit. Controlled refeeds and some cheat days when leptin/ Kortisol has been trough the rough and have been plateauing for too long. Haven’t experienced too much of it though, so I guess I’m lucky. Again thanks Andy for giving out so much, and I truly appreciate everything that you and your peers do to contribute to this industry that is packed with nonsense and BS.

    1. Tom, thank you.

      To maintain professional integrity it’s necessary to decline people sometimes. Despite my bet efforts to explain reasons, whenever I do this it’s nearly never taken well, and I kinda feel like a dick.

      So I most appreciate you taking the time to comment here. 🙂

      1. Tom Øberg Framnes says:

        My pleasure Andy. 🙂

        Sometimes making the hardest choices is always difficult when one is trying to do it out of honesty and integrity.

        And sometimes( most of the time, I know ) people just don’t understand that a NO, can be given out of the best intentions FOR their sake, not yours.

        That’s what’s separate you and your peers from the rest of the bunch. You desire to help and want results, but not by any means necessary
        ( especially those of the unrealistic/ un-obtainable kind)

        So we the community are the ones who are in true gratitude, and I just wanted you to know that. 🙂

        1. Sincerely appreciated Tom!

  29. Szoták András says:

    Hah, my first thought when I’ve seen the dude was “Wow, he looks very good for a pro (read: not natural), big but still appealing to the eye. ” Then proceeded to read the article.

    1. He’s looked insane in person. Outmuscled by 35lbs by everyone at bodypower and still walked away with the win because his conditioning, shape, and symmetry were all insane.

      He’s not someone I’d believe was drug free with no reservations (since I don’t personally know him), but I will say that he’s been BBing for over 20 year, and if he’s been on gear this whole time, he’s not showing any side effects from it.

      1. Ryan Saplan says:

        Greg, with your comment, it makes me wonder how people suffer from near to very little side effects from steroid use. I know alcohol is a lot different, but it makes me wonder because I’ve had a few clients that have made claims to never have had a hangover (and they drink like fish). I on the other hand, get an allergic reaction to wine. And a glass of bear will usually give me a mild hangover the next day.

        1. Just my thoughts Ryan,
          “…it makes me wonder how people suffer from near to very little side effects from steroid use.”
          – There are drugs to manage the side effects. (Otherwise people end up with non-functioning balls.)

          That aside, different people are different. – I am a special flower Ryan, like you. Allergic to a load of stuff I shouldn’t be, but unfortunately am. Apples, peaches, strawberries, pears… they mess me up. Greg Nuckols – blow some pollen in his face and it’s your chance to down the gentle giant in a fit of sneezes. I’ve watched some Japanese people drink two sips of wine and literally fall off their chair at the dinner table.

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