Maintenance-Compatible Muscle Mass (MCMM)

How Much Muscle Can the Body Sustain — Not Just Grow?

We have spent decades asking the same question: How much muscle can I build?

But when I see muscular people developing metabolic problems or becoming unhealthy, I think there is another question we need to ask particularly when we talk about healthspan:

How much muscle can my body sustainably maintain?

Analogy: Think of it like a middle-class family buying a luxury car. They may be able to purchase a second BMW or Mercedes. But they may choose not to, because buying it is one thing. Maintaining it is another.

This question led me to propose a concept I call Maintenance-Compatible Muscle Mass (MCMM).

As if the world needed another acronym! But stay with me. The reasoning is more important than the acronym. MCMM is my attempt to look at muscle not simply as something we build, but as something the body must continuously fuel, maintain, repair, recycle and regulate.

Muscle Is Living Tissue

Muscle is undoubtedly one of the most valuable tissues we possess. It improves strength, movement, glucose disposal, physical independence and functional capacity. As we age, preserving muscle becomes increasingly important. But muscle is not a static structure. Every gram of muscle contains enormous amounts of biological machinery that is constantly working.

Inside a muscle cell, mitochondria are producing ATP. Ribosomes are translating mRNA into proteins. The endoplasmic reticulum is involved in protein processing. Lysosomes break down cellular material. Proteasomes remove damaged or unwanted proteins. Autophagy recycles cellular components. DNA repair machinery monitors genetic damage. Membranes transport nutrients and waste. Immune and inflammatory systems constantly survey the environment.

And all of these systems require resources. A cell is not simply a bag of muscle proteins. It is an extraordinarily expensive biological factory. The larger and more active the tissue becomes, the more biological infrastructure is required to support it.

This is where the conversation about muscle becomes much more interesting.

The Muscle You Build Becomes a Maintenance Obligation

Most muscle building programs follow a relatively simple philosophy:

Stimulate → eat → recover → adapt → repeat.

Mechanical tension stimulates signalling pathways. Nutrients provide substrates. mTOR activity increases. Ribosomes increase protein synthesis. Muscle grows. But once the muscle has been built, the biological process does not stop.

Those proteins have to be maintained.

  • Old proteins have to be broken down.
  • Damaged proteins have to be identified.
  • Misfolded proteins have to be removed.
  • Cellular components have to be recycled.

Mitochondria have to be maintained. Waste has to be cleared. And new proteins have to be manufactured to replace what has been lost.

In other words: Building muscle creates a maintenance requirement. And this maintenance is not performed by one system. It requires the coordinated activity of mitochondria, ribosomes, proteasomes, lysosomes, autophagy, immune surveillance and numerous other cellular processes.

That is why I believe simply saying “more muscle is better” is an incomplete argument.

The Cellular Trade-Off

Here is where my Balance Theory becomes relevant. The cell has limited resources and competing priorities. When we repeatedly stimulate anabolic pathways such as mTOR, we are essentially telling the cell:

Build. Grow. Synthesise.

At the same time, pathways associated with energy sensing and cellular conservation, including AMPK, help the cell respond to energetic stress and regulate processes such as mitochondrial function, autophagy and metabolic homeostasis. These pathways do not operate independently.

The body has to decide where resources go. More construction creates more material that eventually needs quality control. More cellular activity creates more metabolic by-products. More tissue creates more maintenance. And maintenance itself requires energy. This does not mean that mTOR is bad or that AMPK should always be high. Quite the opposite. We need anabolic signalling to build and repair tissue. The issue is chronicity and balance.

Biology rarely works on the principle that “more of a good pathway is always better.”

The question is whether the stimulation remains compatible with the rest of the system.

It Is Not Just About Energy

This is an important distinction. When I talk about the maintenance cost of muscle, I am not simply talking about calories.

The body needs much more than energy.

It needs the machinery to use that energy.

It needs functioning mitochondria to produce ATP.

It needs ribosomes to manufacture proteins.

It needs proteasomes to remove damaged proteins.

It needs lysosomes and autophagy to recycle cellular components.

It needs immune surveillance to identify problems.

It needs signalling systems to coordinate all of this.

It needs adequate recovery to restore the system.

Therefore, the question is not simply:

“Can I eat enough to maintain this muscle?”

It is:

“Can my entire biological system continuously support the muscle I have created?”

That is a very different question.

When More Muscle Becomes a Different Problem

Imagine two individuals with similar training histories. One maintains a very muscular physique but requires large quantities of food, continuous high-volume training and significant nutritional intervention simply to remain there. The other carries slightly less muscle, trains moderately, eats ordinary food, recovers well and maintains stable metabolic and physiological markers.

Who has the more sustainable system?

I am not suggesting that the first individual is necessarily unhealthy. I am suggesting that maximum muscle and sustainable muscle are not necessarily the same thing. The first individual may have reached a level of muscularity that is possible to achieve, but expensive to maintain. The second may be closer to their biological equilibrium.

This is where I introduce Maintenance-Compatible Muscle Mass.

What Is MCMM?

I define Maintenance-Compatible Muscle Mass (MCMM) as:

“The amount of muscle mass an individual can sustainably maintain while supporting healthy energy metabolism, protein turnover, cellular repair, recovery, physical function and metabolic health without requiring excessive physiological or nutritional support.”

The key word is sustainably.

MCMM is therefore not:

  • the maximum muscle you can build
  • the maximum muscle you can maintain through aggressive supplementation
  • the maximum muscle you can maintain by continuously increasing food intake
  • or the amount of muscle that simply looks aesthetically impressive

It represents something different: the amount of muscle that remains compatible with the capacity of the whole organism.

MCMM and Ageing

This concept becomes particularly relevant as we age. Ageing is accompanied by changes in mitochondrial function, anabolic responsiveness, protein synthesis, cellular quality control and recovery capacity. The machinery does not necessarily stop working.It may simply become less efficient.

Now consider what happens when we add more tissue to the equation.

  • More muscle means more proteins to maintain.
  • More proteins mean more turnover.
  • More turnover means greater demand on synthesis and degradation systems.
  • More cellular activity creates metabolic by-products that have to be managed.

And all of this must occur while the ageing organism may already be experiencing declining efficiency in some of these systems. This does not mean that older people should avoid building muscle. Quite the opposite.

Muscle is one of the greatest functional reserves we possess. But perhaps the objective should shift from:

“How much muscle can I build?”

to:

“How much functional muscle can my system sustainably support?”

That distinction may become increasingly important with age.

MCMM Is Individual

There cannot be a universal MCMM number. It cannot simply be calculated from height, weight or BMI. Two people with identical body weights can have completely different capacities to maintain muscle because of differences in genetics, mitochondrial function, training history, nutrition, recovery, hormonal environment, metabolic health and cellular efficiency. One person’s sustainable muscle mass may be another person’s excessive biological burden.

Therefore, MCMM is not a target number.

It is a framework. It asks us to consider the relationship between the muscle we possess and the biological systems required to maintain it.

The Bigger Question

This is ultimately why I believe MCMM fits naturally within my proposed Balance Theory. The body is not a collection of independent pathways that can be maximised one at a time. Energy supports construction. Construction creates maintenance. Maintenance requires energy. Repair requires machinery.

And the machinery itself has to be maintained. The objective, therefore, should not necessarily be to maximise muscle, mitochondrial activity, protein synthesis or any other individual pathway. It should be to find the point where these systems remain compatible with one another.

That leads to a different definition of muscular success. The biggest muscle you can build is not necessarily the best muscle you can carry. Perhaps the better goal is the amount of muscle that gives you the greatest functional advantage while remaining compatible with your body’s ability to fuel, repair, regulate and maintain it.

So, How Do You Know Your MCMM?

Here is another analogy.

If building muscle was the only thing the body needed, there would be no need for stretching, yoga, fascia work, movement science, mobility, relaxation or recovery. The fact that we need all of these tells us something important: the body is not designed simply to build. It is designed to build, adapt, regulate, repair and maintain.

So how do you know where your Maintenance-Compatible Muscle Mass lies?

As a professional trainer, I believe I had figured out my own MCMM more than a decade ago. Not because I had calculated some magical number of kilograms of muscle, but because I noticed something much more important:

I could continue training for years without recurrent injuries, maintain my body composition and health markers, and sustain my muscularity without relying on supplementation or an extreme diet.

That, to me, is a much more meaningful definition of sustainable muscle.

So here is my proposal for identifying your MCMM.

1. Can you train consistently without constantly breaking down?

You should be able to train for years without your body repeatedly telling you to stop through niggles, pain or injury. That does not mean you should never take a break. I take breaks too – sometimes for months. But there is a difference between taking a break because you choose to and being forced to stop because your body cannot keep up. I may move from resistance training to cardio, yoga, walking or simply doing less. Boredom is perfectly acceptable. Constant breakdown is not.

If your muscularity requires you to repeatedly push through injuries, take prolonged recovery periods or constantly manage niggles just to preserve it, perhaps you should question whether that level of muscle is actually compatible with your system.

2. How much muscle can you maintain without extreme inputs?

Build your muscle. Then step back. Can you maintain it with ordinary food, sensible training and normal recovery? And yes – I would even say, drop the whey. If removing supplements or dramatically increasing your dietary manipulation causes your muscularity to disappear, then perhaps what you built was not entirely maintenance-compatible with your normal lifestyle. This does not mean supplements are inherently bad. It simply means that MCMM asks a different question:

What can your body maintain without extraordinary assistance?

3. What happens when you eat to fullness?

This is an interesting experiment. Eat normal, satisfying food rather than deliberately restricting calories to preserve a particular physique. Then observe what happens to your body weight and composition over time. If your weight continues climbing, something in the equation is changing. Perhaps your training stimulus is no longer sufficient for your current intake. Perhaps your energy intake is simply exceeding what your system requires. Perhaps your activity has changed. The point is not to demonise food or calories.

The point is to observe what your body can naturally regulate and maintain.

So What Does Your MCMM Look Like?

If you can:

  • Train regularly without recurrent injury or constant niggles
  • Eat home-cooked food as we do, with occasional junk
  • Maintain your muscle without depending on supplements
  • Maintain relatively stable body weight and body fat
  • Recover adequately and remain physically capable
  • Maintain healthy metabolic and other relevant health markers

Then the muscular structure you can sustain under those conditions may represent something close to your Maintenance-Compatible Muscle Mass.It may not be the biggest body you can build. It may not be the physique that wins a bodybuilding competition. And it may not even be the physique you could achieve by manipulating every variable in your favour. But it may be the physique your entire biological system can afford to maintain.

And perhaps, when we talk about healthspan, that is the more important number.