Exploring the Natural Muscle Growth Debate

Most people try to solve the “natural or not” question with one quick test: look at a physique and decide whether it sits below or above an imaginary line.

The surprising part is not that this fails. It is that the line moves wildly depending on who is judging.

One person draws the cutoff around Will Tennyson. Another draws it near Simeon Panda. Some viewers even argue that The Rock is natural, and millions bought the Liver King story until it unraveled into a reported $10,000-per-month steroid cocktail.

This article follows the video’s unique, investigative angle: instead of pretending there is one perfect visual tell, it uses history, science, and common sense to get closer to an answer that actually helps everyday people set realistic goals.

The “natty line” problem, and why eyeballing fails

The “below the line equals natural, above the line equals enhanced” framing is tempting because it is fast. It also matches how social media works, scroll, judge, move on.

But this approach breaks down for a simple reason: people are not comparing the same things.

Some viewers focus on size. Others focus on leanness. Others lock onto skin texture, facial puffiness, or “3D delts.” And many comparisons are distorted by lighting, angles, filters, pump, dehydration, and posing.

A key insight in the discussion is that trust has become a fitness problem. When enough influencers misrepresent how they got their physique, the audience stops believing almost everyone. That skepticism is understandable, and it can also become corrosive, because it pushes people toward extreme conclusions like “anyone impressive is on steroids.”

Did you know? Trust can be influenced by labels and expectations, even when the underlying reality has not changed. Research on perceived authenticity shows that whether something is labeled “natural” or “artificial” can shift how much people trust it, independent of the actual content (Collabra: PsychologyTrusted Source).

That does not mean skepticism is wrong. It means snap judgments are fragile.

What to look at instead of “vibes”

A more grounded approach is to combine multiple clues, especially ones that can be checked.

Short version: you want a case, not a vibe.

History check: when steroids entered the picture

Before you argue about what is “possible naturally,” it helps to know when the relevant drugs even existed.

The video walks through a timeline that is surprisingly concrete.

Testosterone was first isolated in 1935 by a Dutch pharmacologist, Ernst Laqueur, using an approach that sounds almost unbelievable today: processing thousands of bull testicles to extract the hormone. By the early 1940s, clinicians were experimenting with testosterone for what they called “male menopause,” meaning symptoms like low mood and low sex drive.

Here is the key turning point: testosterone was not widely used as a performance enhancer until people realized what it could do in sport.

The discussion highlights the 1952 Olympics in Finland as a moment when suspicion spiked, after Soviet weightlifters suddenly dominated with three gold medals. Then, in 1954, anabolic steroid use entered bodybuilding lore when Dr. John Ziegler injected John Grimek at the York Barbell Club.

Why does this matter for your training and health?

Because “pre-steroid era” physiques act like a natural experiment. If the drugs were not available, the bodies you see from that time are strong evidence of what humans can build without modern anabolic help.

Pre-steroid physiques as reality checks

Steve Reeves is used as a practical example: a 1947 physique at 6'1", 215 lb, estimated 10 to 12% body fat, at age 21. The reason he is featured is not that he was the biggest, but that people across the spectrum tend to agree his look is achievable naturally.

Then the argument gets even stricter: go earlier than 1935.

Eugene Sandow, photographed in 1897, around 5'9", 185 lb, roughly 10% body fat, is a clear “no steroids existed” example. Sandow also reportedly recommended very light weights (5 to 10 lb for 10 to 15 reps), which is a reminder that training knowledge and equipment were far from optimal.

The implication is subtle but important: if these physiques were possible with worse tools, it is unlikely they represent the absolute ceiling of drug-free development.

FFMI, the jackedness yardstick (and its limits)

If “eyeballing” is unreliable, you need a metric.

The video centers on FFMI, or fat-free mass index, which estimates muscularity relative to height. It is calculated as lean mass divided by height squared.

This is not a magical number. It is a way to compare people of different heights using the same language.

The 1995 FFMI study that shaped the debate

A major part of the argument comes from a 1995 study (Kouri and colleagues) that recruited lifters from gyms in Los Angeles and Boston, asked whether they were natural or enhanced, then urine tested participants to reduce lying. Researchers measured height, weight, and body fat using hydrostatic weighing, and then calculated FFMI.

The headline finding became famous for a reason: among 74 verified natural lifters, not one had an FFMI above 25. Every lifter at 25 or higher was using steroids.

That created the now-common “FFMI 25 natural limit” idea.

What the research shows: In this dataset, FFMI above 25 was not observed in verified natural lifters, leading authors to suggest that only rare individuals might exceed 25 without anabolic drugs.

But the video does not stop at the headline.

It points out two details people often ignore:

So FFMI is useful, but it is not a courtroom verdict.

Why “25” is not a brick wall

The discussion cross-checks FFMI 25 against pre-steroid champions.

Using pre-steroid era Mr. America winners (1939 to 1949), several winners appear to exceed 25, including one listed around 25.5, and multiple others above 25 from 1943 to 1949.

The practical takeaway is not “FFMI 25 means natural.”

It is this: FFMI 25 is uncommon drug-free, but not impossible, especially when you look at elite performers, large populations, and measurement uncertainty.

A second cross-check comes from a 2017 study on Division 1 and 2 college football players, where the average FFMI for offensive linemen was about 25.1, and some players exceeded 25. The video acknowledges the obvious caveat: drug testing exists, but it does not guarantee zero PED use.

Still, it would be a stretch to assume every large athlete is enhanced.

Important: FFMI depends on accurate body fat estimates. A small error in body fat percentage can move FFMI meaningfully, especially in lean people. Treat FFMI as a range, not a single definitive point.

How fast can muscle grow naturally? The transformation trap

Size is one argument. Speed is another.

The video uses a specific example from influencer culture: a claim of going from 134 lb to 184 lb in three years at roughly the same body fat.

That kind of before-and-after is exactly where “fake natural” debates explode, because timelines feel more suspicious than physiques.

The analysis here is more nuanced than “possible” versus “impossible.”

Typical muscle gain ranges (and what they miss)

The video cites a practical table for realistic muscle gain rates in men:

That creates a 3-year range of roughly 17.5 to 42.5 lb of lean mass for many men.

So a reported 50 lb of lean gain in three years is above the typical range.

But “above typical” is not the same as “impossible.”

The underweight baseline explanation

Here is the common-sense twist: starting very underweight can inflate transformation math.

The video references an average FFMI around 19.8 in a sample of healthy untrained men, and contrasts that with a starting FFMI of 17 in the example. At 5'11", that gap could mean the person began well below a well-nourished baseline.

In everyday terms, some early “muscle gain” is actually:

That is why the video treats the timeline as “suspicious but possible,” especially when paired with normal FFMI and normal blood work.

Pro Tip: If you are comparing your progress to online transformations, calculate your own baseline first. If you started underweight or were dieting hard, your first goal can be restoring to a healthy weight and consistent intake before you judge your “muscle gain rate.”

Expert Q&A: “Can blood work prove someone is natural?”

Q: If an influencer shows normal blood work, does that prove they never used steroids?

A: Normal labs can add context, but they are not definitive. Some drugs clear quickly, and timing matters, so a normal panel does not rule out past use.

A more useful approach is to view blood work as one piece of a bigger picture that includes FFMI, timeline, photos, and consistency of claims.

A. Patel, MD, Internal Medicine

Common sense and outliers: why freak genetics are real

One of the most human parts of the video is the reminder that extreme variation is normal in a world of 8 billion people.

Someone is the tallest. Someone is the shortest. Someone is the hairiest. Someone is the strongest responder to training.

So the question becomes: if rare outliers exist in height and longevity, why would muscle-building outliers be impossible?

The genetics study that reframes “fairness”

A classic training study is used to make the point: hundreds of men and women ran the same 12-week biceps program, and MRI measured growth. Most gained around 20%, but some gained nothing, and some gained 40 to 55%.

Same program. Wildly different outcomes.

This framing changes how you should interpret social media physiques.

It is not that genetics explains everything. It is that genetics can explain enough that “I have never seen it” is not a strong argument.

A reality check using two extremes

The video contrasts a high natural outlier with an enhanced legend.

Those numbers are not close.

That gap is the practical reason FFMI is helpful for wellbeing: it can protect you from chasing a fantasy that quietly pressures you into risky choices.

And it can also protect you from the opposite trap, assuming your genetics are “bad” because you do not look like a rare outlier.

Resource Callout

»MORE: Build a realistic “natural potential” worksheet. Track height, weight, estimated body fat, and strength trends for 12 weeks, then reassess goals based on your own data rather than influencer comparisons.

Practical targets: what “natural” might look like at your height

After the history and science, the video lands on a practical answer.

For an average male who trains hard, eats appropriately, and stays consistent, a realistic long-term target is often FFMI 22 to 24, with 25 as a possible upper end for some people with strong genetics and time.

That is the “common sense” conclusion: most people can become impressively muscular, but not infinitely muscular.

Translating FFMI into real-world body weights

Using the video’s examples at around 12% body fat, an FFMI of 24 roughly corresponds to:

These are not promises. They are ballpark targets that can help you plan.

And planning matters for health.

If your goal weight implies you would need to stay extremely lean year-round, or gain at an aggressive pace, that can increase the risk of disordered eating patterns, chronic injuries, sleep problems, and body image stress.

How to use this information without spiraling

You do not need to compute FFMI every week.

But you can use the framework to keep your expectations grounded.

Pattern A, quick checklist you can apply today:

A short closing thought: the most useful “natty limit” is not a number you use to accuse strangers online. It is a number that helps you stay patient with your own body.

Expert Q&A: “Is FFMI a good goal for health?”

Q: Should I chase an FFMI number to improve wellbeing?

A: FFMI can be a helpful reference, but it is not a health score. Cardiovascular fitness, sleep, nutrition quality, injury risk, and mental health matter just as much as muscularity.

If tracking FFMI increases anxiety or pushes extreme dieting, it may be better to focus on strength progress, energy, and sustainable habits.

L. Chen, RD, Sports Dietitian

A note on incentives and “fitness certainty”

The video ends with a nutrition app promotion, which is common in fitness media. That is not automatically bad, but it is worth remembering that confident claims can be amplified when money is involved.

Healthcare research has long discussed how conflicts of interest can influence recommendations and guideline development (NCBI BookshelfTrusted Source). Fitness content is not clinical practice guidelines, but the same human incentive problem applies.

You can appreciate the framework and still keep your critical thinking turned on.

Key Takeaways