What’s My Maximum Muscular Potential?

This question has been asked multiple times over on many bodybuilding forums and message boards since the inception of the internet.  While this question’s answer depends solely on an individual’s genetic ceiling, there’s one very comprehensive resource I’d recommend to anyone in search of reaching their genetic potential for maximum muscular growth.

The resource I am referring to today is an ebook called Your Muscular Potential by Casey Butt Ph.D.  He runs the website Weightrainer.net and has devoted insurmountable hours to the study of maximum muscular gains in the drug-free physique athlete.

Casey holds a degree in mathematics, a degree in physics and has his PhD in artificial intelligence for controls engineering.  He’s spent the last 18 years in a mad obsession with weight training and altering his body composition through bodybuilding.  He also admitted that he wasted his first 10 years of weight training by following the shoddy information found in muscle magazines.

If you’re anything like me and have become obsessed with maxing out your gains in the name of science, sound training principles and pure, hard work, then this is the perfect book for you.  And at a mere $9.95 (not an affiliate link), it’s a steal.  Hell, just give up 3 of your lattes this month.  You’ll save on about 1200 kcals and have an awesome resource in your hands (err, on your hard drive).

So what’s in the book and why should you purchase it?

Training Expectations

This is probably my favorite part of the book.  Since I’m a big fan of objectivity and being realistic when it comes to setting physique and strength goals, this part of the book really got my jollies off.

In this section, Casey gives you a bunch of fancy formulas (not found on his site) to predict your genetic maximum muscular potential based on physiological factors such as height, wrist and ankle circumference.  From his research, there tends to be a precise correlation between bone size and maximum muscle gains.  In short, the thicker your wrists and ankles, the more aptly you are to pack on the most mass.

Before we go any further, Casey does address the commonly asked question skinny guys ask about the hardgainers potential.  What classifies someone as a hardgainer and what can they expect in terms of maximum muscle gains over their lifetime?

While wrist and ankle circumference play into the maximum muscular equation, muscle belly length plays an equally important role.  From the book:

You can make a self-assessment of your muscle belly lengths by checking to see if you have longer tendons attaching your muscles to the bones than the average trainee of your height. In other words, do you have big gaps between the ends of your muscles and the bones to which they attach? If you do, then you have short muscle bellies in the muscles in question.

However, just because you have a small bone structure doesn’t mean your muscle bellies will be short.  There is a small percentage of the population who break these rules; they are called the genetic outliers.  Congratulations if you are one.

Elite Drug-Free Bodybuilders and Genetic Freaks

In this section, Casey gives even more equations and measurements of the elite-level bodybuilders and what some might call genetic freaks. One of the famous names you will recognize in this section is Reg Park, who even to this day has an incredible, respectable build.  His size is nothing compared to the drugged up freaks but I’m sure most of us find the natural look to be more in line with our ideals of looking great naked.

What I do find interesting is while Reg Park and others he mentions in this section were indeed of the elite status, they still failed to reach the maximum muscle measurements in all categories (chest, biceps, forearms, neck, thighs, calves measurements).

He also mentions that this section should be taken with slight skepticism because while the equations are based on the measurements of elite-level drug-free bodybuilders, some of their claims are questionable given how easy it is to pass a drug test.

This is my favorite part of this section.  In Casey’s words:

It cannot be stated strongly enough that it is completely unreasonable for the genetically typical trainee to think that he can reach the level of development described in this section. Few world-champion drug-free bodybuilders do so, nor do even the majority of anabolic drug-users.

In the next section, Casey then explains what the Greeks believed to be the most attractive measurements and compares them bodybuilding standards and the standards of the general population in terms of what constitutes a beautiful male physique.

How To Set Training Goals

This is probably the most valuable part of the book in my opinion.  Here, Casey suggests that a majority of the population will do well just to reach what he outlines for maximum muscular size and measurements in section one, Training Expectations.  If after years of solid training and muscle gains you surpass the size and measurements described, set your standard higher and onto reaching the Elite-Level of even Genetic Freak level.

To give you an example of what someone might expect in terms of maximum size according to section one, I took some measurements and will give you my results for illustrative purposes.

Height: 68 inches
Wrist Circumference: 7 inches
Ankle Circumference: 9 inches

The calculations from section one puts me at about 186lbs at 10% body fat for my maximum muscular potential.  There are a few more equations that come with the purchase of the book and here are my readings for those (all are based upon body fat being at 10%:

Muscular Potential: 190.8lbs
Hardgainer Potential: 181.3lbs
Championship Physique:
“Freak” Physique:
Sexiest Physique(Greek Standards) :

The picture at the top of the page and the half-naked one on my about page were taken about 2.5 years ago so it looks like I reached the Greek Standard for the Sexiest Physique a few years back.

Remember, these are just estimations and only time and hard work (plus genetic limitations) will determine if I can surpass the potential of 186lbs at 10% body fat.

Just keep in mind, only a small fraction of the population will ever reach these numbers and some will have to resort to drug use to hit the elite-level.  I don’t care how much Anaconda you take, you still have to accept these facts backed by the mounds of data and research Casey has bestowed upon us.

In the next section he gives “real-world” examples and compares his size and his accomplishments to those like John Grimek, Ron Lacy, Layne Norton and Tommy Jeffers.  This is all respectable to individual measurements in wrist, ankle circumference and height.

Summing Up

If you are solely interested in reaching your maximum muscular potential and want a resource that is backed by research, Your Muscular Potential is the way to go and I can assure you will not be disappointed.

While you may (or may not) find the statistics to be discouraging, it will allow oneself to be more realistic with your potential for long-term gains in muscle and size.

26 thoughts on “What’s My Maximum Muscular Potential?”

  1. Interesting article. It made me think that siblings could be completely different too. My sister literally looks at a dumbbell and gains muscle (hate her!). ;) Me…not so much. My two sons are total opposites as well. Even at their young ages, (10 and 6) you can tell the bodily differences in them. My older one is a classic hardgainer while the younger one is built like a football player, lol.

  2. hey, this article’s a great tool. Turns out I’ve been way off base as far as my goals are concerned. I was working with a goal weight of about 150 lbs shredded (i told you the resources in past emails) and in reality i got a way to go, especially since all of my measurements are basically identical to yours and i only weigh a buck 50. Oh well, guess its time to eat me some sammiches! :)

  3. This is very interesting stuff indeed.

    You and I already discussed this via email, but I apparently lean toward the genetic freak end as my wrist and ankles measure about what yours do but I’m a good deal shorter.

    As of right now, I’ve dieted back to 190 pounds and I’m getting pretty lean again. (at my biggest I was 205 and probably 15% bf) Lost most of the fat, (and sadly some muscle, as evidenced by the drop in squat numbers) to get down to 190.

    I am getting married this summer, and my goal is to see if I can gain another 5 pounds of muscle and lose another 5 pounds of fat by then (a 10 pound body recomp). The trouble is that I’m an Oly lifter, and so my main priority is always how much I lift, not what I look like. But, it would help my lifting if I can be a leaner and more muscular 187 pound-class lifter.

    That said, I’m pretty sure the only way I can gain that kind of mass is to put it into my upper body. My lower body is already ridiculous! But, I never really work my upper body very hard. I just half-ass some stuff at the end of my Oly work. I would bet if I dedicated myself to building a bodybuilder’s upper body, I could be very lean at 200 pounds, and at 5’6”, that’s freaky.

  4. I am wondering if anyone has an opinion on what casey butt has to say about strength limits in the bench, squat and deadlit?

    • I’m not sure what to think of it. I have a small frame, 6.5 wrist and 8.75 in ankle. I struggle to put on mass so my strength gains probably won’t be the stuff of legends. Using the Hardgainer calculations the Bench goal seems just about right.

      I will say the Deads and Squats feel a bit low though. I think the lifts I would be able to attain are the ones for a normal lifter.

      I’m guessing you can’t be neatly tied in to one “frame” and you’ll likely experience that your body responds to different lifts, based on what I’ve read. The hardgainer goals are probably something you should shoot for at the very least.


  5. I use the finger test for women, but that’s another test entirely.


    I can fit 3 fingers quite easily between my bicep muscle belly and the crook of my elbow. Genetic freak fail.


  6. Hey JC, I like the underlying issues of this post. I strongly believe that we should all set the goals that we want but remember that we have unique physiques and not be disheartened if we cannot look like Mr Muscle magazine.

    My natural build is tall, slender, thin wrists, long muscle tendons. It is by no means ideal for body building, more triathlon and athletics perhaps. Years ago I spent time with wrist curls and neck raises. They work to some extent and of course boxers etc show us that you can build size around your bone structure in these areas but I have discarded these exercises now in favour of compound lifts. I’ve been training for 13 years and my adult physique has fluctuated but I will always have longer limbs, and I work with that now, not against it.

    So I say, don’t be limited by your ‘natural skeleton’ because we can all use exercise to sculpt our bodies but remember to cherish your unqiue physique and not beat yourself up too much. I actually wrote about this over on LMD Fitness, all be it without the scientific formulas but it is quite nicely linked to this post – http://www.lmdfitness.com/training/your-unique-physique-2/

    Cheers JC and co

  7. Nice! You finally came round to posting about this.

    It’s too bad that Casey hasn’t done a similar study with female bodybuilders. That said, the female body is different enough that the measurements used on males may not hold. Still, though the numbers may not be useful, the principle of muscle belly length and thus potential for muscular development still holds.

    @Eric. If you’re talking about biceps, then two fingers is quite a fair bit. O well, at least you’re better off than me (I can fit 3!).

  8. I love when things make sense due to math and science. I will be checking this ebook out for sure. Thanks for sharing.


  9. Pretty interesting but being a woman, I guess for me it does not pertain & I don’t want to get bigger anyway.. just stay tight as possible as I age.

    Just a side note as I did not comment to your previous post because I am so NOT the norm & can overtrain & still gain. In 6 months of lifting just a tad heavier & not heavy compared to a woman lifting heavy, I gained some decent size in my arms, back & shoulders where I was trying to gain.. and I do tend to overtrain, I hate to say cause I love the weights so much. I am not the norm though so ladies, don’t get scared! :-)

  10. Awesome. I’ve visited Caseys site via Lyles article, interesting stuff. And for $9.99… cheap price to pay to get your head on straight about realistic progress & expectations.

  11. Hi JC-
    I know women can expect roughly half the gain as guys, but when I tried his online calc it didn’t make sense at all. Does he addess the wimminz in the book?

    • Erin, I’m sorry but the only time teh wimminz(this gave me the lolz) are mentioned in the book is in the chapter where he talks about the ideal(Greek) physique.

  12. This may go without saying, but I recommend people read the book and not just plug in the formulas. I have the measurements of a little girl but Casey goes into how I may not actually be a hardgainer, even with a small frame, because other conditions are met.

      • LOL, muscle bellies, that just sounds funny…. they are not extremely long but they aren’t short. I can fit two fingers just perfectly. Still takes me forever to gain though.

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