Diet and Nutrition

Hypertrophy Cluster Training (HCT-12) – Key Principles to Growth

There’s a reason why the book Eat Less and Exercise More never made it to the top of the bestseller lists, yet “Lift Progressively Heavier Weights and Eat Consistently” is the mantra of every successful lifter. People do not like the simple reality about what it takes to improve their bodies.

The depressing truth is that the majority of gym goers and Internet posters have just not achieved the overnight growth they expected.

They agonize over the most intricate details of time under tension, insulin regulation, muscle protein synthesis, carbohydrate source, protein source, nutrient timing, testosterone and growth hormone spikes, cortisol manipulation, being anabolic, rep ranges, exercise selection and so on.

All that this vacillation accomplishes is to prevent them from acknowledging that their own lack of commitment and consistency is the reason they don’t even look like they lift. I blame the Internet as well as our innate desire for a shortcut, there’s too much information at our fingertips. Combine ignorance with wanting to believe and you’ve got a recipe for zero results and 90% of all the posts on bodybuilding websites (the 10% being Wannabebig 8) ).

So here we are, with what we believe is the best muscle building program out there, but we can’t in good conscience just pile on more info. Rather than ram it down your throats with promises of huge gains, we’re going to give you the science behind why it works, so you’re not only armed with a program for getting as big as you possibly can, but you’re also able to critically evaluate what everyone else out there is trying to sell you.

“I would not give a fig for the simplicity this side of complexity, but I would give my life for the simplicity on the other side of complexity” (Oliver Wendell Holmes), which is a cool way of saying — the more I learn, the more I realize that only a few things truly matter.

We’re not going to stop you jumping straight to the HCT-12 Training Program. After all, if you want to be the biggest you’ve ever been, you’re going to have to put it into practice, but like Oliver Wendell Holmes said, if you bear with us, and push through to the other side, everything in the bodybuilding world will become a lot simpler, and your physique will never be the same again.

Download the HCT-12 Bodybuilding Program (3.29MB)


The human body, your body and mine, are the result of millions of years of evolution. In the 100,000 years or so that we’ve been around, our environments have changed, but the internal mechanisms responsible for growth and the stimuli to which they react have not.

The mechanisms that allowed us to adapt to our surroundings, to the tasks that kept us alive and nourished, have not changed, and will not change in your lifetime. So barring external agents that can manipulate our DNA and/or hormonal status (i.e. drugs), what works for getting people bigger is the same now as it was and always will be.

Muscle growth (hypertrophy if you will, but let’s keep it simple) is an adaptive process that is stimulated by a very specific set of demands, they apply to you, me and every able bodied person on the planet. You’re just not that special!

We’ll get to the mechanisms of growth shortly, but just so we’re clear, the process of adaptation is an evolutionary survival trait. We react to stressors both acute (short term) and chronic (long term), with acute and chronic processes. When cold, we get goose bumps, our hairs stand on end trapping air for insulation, and then we shiver to generate heat if this isn’t helping. When hot we sweat, to cool our skin through evaporation.

When regularly faced with a heavy enough object that makes us struggle to move it, we develop bigger, stronger muscles to make sure we can move it with less effort next time. And that is it, Specific Adaptation to Imposed Demand, as it applies to growth.

Muscle growth is an adaptive process that is stimulated by a very specific set of demands


Your muscles are comprised of Motor Units (MU) — the collective term for the motor neuron (a nerve) and all the muscle fibers it innervates/controls.

The motor neuron is connected to the spinal cord which in turn connects to the brain; collectively, the Central Nervous System (CNS). Include muscle in there and we get the Neuromuscular System, in this context we’ll simply refer to this as the Nervous System.

When the Nervous System (in response to a load) sends a signal to the muscle to contract, the motor neurons instruct the attached muscle fibers to shorten and tighten, creating tension. The greater the load, the greater the number of motor units needed, the greater the contraction, and the greater the tension (it is this ‘tension to which the term Time Under Tension refers).

When muscle fibers contract they deplete cellular energy, and if they contract hard enough and long enough cellular energy depletes completely (AKA fatigue). Wernbom et al show that cellular energy expenditure affects growth, possibly because the reduction in cellular energy renders the muscle fiber stiffer (less elastic) increasing the potential for damage.

What that means to us is that not only does the load need to be heavy enough to create the requisite tension, but that the load needs to be lifted repeatedly enough (i.e. fatigued) to fully stimulate growth.

When enough tension is applied to the muscle fibers for enough time, chemical messages are sent to the nucleus of the cells (where your genes are) within the muscle, and instructions (held in your genes) are sent back detailing how to create that particular muscle protein from the amino acids in the blood, this is called muscle protein synthesis. Amino acids from the bloodstream are integrated in to the muscle fibers to increase their cross-sectional area, increasing their strength potential, so that the stress of the next training session won’t be as disruptive.

The size of the muscle is determined by the total size (or cross-sectional area) of all the muscle fibers within it and the cross–sectional area of a muscle fiber is directly proportional to its strength capacity. A bigger muscle is a stronger muscle. Growth is the result of adding new proteins to the muscle and keeping them there.

Muscle Protein Synthesis increases over a few hours after lifting, peaking at 24 hours and returning to normal over the next 48 hours, so 72 hours after lifting promoted Muscle Protein Synthesis, it reverts back to normal.

The body is in a constant state of flux, and in the muscle this pits Muscle Protein Synthesis (anabolism) against Muscle Protein Breakdown (catabolism). For most non-lifters the effects of this competition are evened out over time with neither overcoming the other. In other words, they neither build nor lose muscle (homeostasis).

Growth depends on Muscle Protein Synthesis outpacing Muscle Protein Breakdown, or if you like, the rate of anabolism has to be greater than the rate of catabolism (Tipton and Ferrando 2008). This small lead accumulates over the weeks, months and years to make your muscles visibly bigger.

Lifting increases Muscle Protein Synthesis, so does eating protein (amino acids). Lifting with amino acids in your bloodstream (after eating protein) increases it further; the effect is synergistic and they do this through the same pathway. This pathway or signal chain is called Akt-mTOR (Goldspink and Yang, 2001, Goldspink 2002, 2003, Ratkevicius, 2008).

Of the two, tension has the largest effect on Muscle Protein Synthesis. This may seem obvious but then some people do believe that just eating protein will give them big muscles. It won’t. They need a reason to grow.

If the stress imposed by lifting is progressively increased the muscle will further adapt (by getting bigger and therefore stronger), but if that stress isn’t repeated, then new muscle isn’t required, so it will be lost to Muscle Protein Breakdown.

Similarly if the stress is repeated but does not progressively increase then the muscle will go through a process of accommodation, and will become more efficient. For the body, efficient means less energy consuming and the muscle will remain capable of performing the task but become smaller.


I detailed above that the higher the load, the greater the tension, the greater the number and size of the Motor Units recruited to lift the load and the greater the potential growth.

In the gym, that load works out to be between 70% and 90% of 1RM (Rhea et al. 2003, Peterson et al. 2004,2005 and Wernbom et al. 2007), which translates to a rep range of roughly between 15RM and 5RM. So getting stronger anywhere between 70% and 90% 1RM (15RM and 5RM) is going to effectively stimulate growth.

We can however narrow it down further by looking into the two factors responsible for strength production:

1) Muscle Fiber Recruitment – We covered this above in Motor Unit Recruitment.

2) Rate Coding – In part this was covered above. Messages sent by the Nervous System control muscle contraction. Rate Coding refers to how fast those messages are sent. The faster they’re sent, the stronger the contraction.

Up to about 80-85% 1RM, you’ll be relying on Motor Unit Recruitment. Above that, Rate Coding Kicks in (i.e. no further Motor Units will be recruited), the fibers will just be made to contract harder. So at around 80-85% 1RM you’ll recruit every Motor Unit you have, which for all intents and purposes means all the muscle fibers. Below 80-85% 1RM, the largest Motor Units are activated only as the muscle fatigues (toward the end of the set). Given the largest MUs have the greatest potential for growth; it makes sense to recruit them from the first rep. So that narrows our rep range even further to between 5RM-8RM.

We’ve defined the minimum tension (weight/load) required for growth, but we also know that this weight needs to be lifted a certain number of times.  Based on decades of training and scientific data to corroborate what we already knew, we get a sliding scale of about 60 total reps per body part at the lighter load of 15RM all the way down to 15 total reps in the 5RM range.

In summary, the effective rep ranges are between approximately 4RM and 15RM for between fifteen and sixty total reps respectively per bodypart.

Because the goal is to maximally stimulate every fiber, our program utilizes the rep range where all muscle fibers are used right from the first rep, which is 5RM to 8RM (anything heavier tends not to introduce fatigue in the way it is required). Being more specific our program focuses on 6RM.

We know that getting stronger anywhere between 1RM and 15RM will make you bigger, and spending time in the lower and higher rep ranges will provide major benefits. For example, a focus on strength in 1RM to 4RM range will carry-over to the higher rep ranges, a focus on the higher rep ranges will improve energy supply and waste removal for the muscles. This means that every program is a compromise. You can’t focus on all the rep ranges all the time and expect to progress, but our program does focus on the rep range that produces the most growth, most of the time.

One interesting and notable exception to the rules above is if you are particularly strong. I don’t have a definition for strong, maybe it’s absolute, maybe it’s relative, but there’s a big difference between repping out 20 reps with something small and pink and a couple hundred pounds or more (depending on the exercise) a la Kroc rows.

This doesn’t violate the principles above however, perhaps the minimum intensity threshold is met with any reasonable rep range if you are as strong or nearly as strong as you can humanly get (i.e. your strength deficit is small), but you have to have spent years of effort and got that strong first. Either way, if when attempting high rep ranges like this, people don’t gasp in awe at the weight you’re using, safe to say, you should stick within the recommended rep continuum.

Growth is stimulated by adequate load and work. Muscular failure doesn’t really come into it. The loads we’ve discussed have been between 5RM and 15RM, which by definition is the maximum amount of weight that could be lifted for either 5 repetitions or 15 repetitions. A true 5RM (or 15RM for that matter) does not reach failure; you succeed in lifting the weight but could do no more. Failure attempts to go beyond this and have you really struggle for that sixth rep but not succeed. Some advocates push you even further than that, with forced reps, etc.

HCT-12 utilizes the rep range where all muscle fibres are used right from the first rep, which is 5-8


You fail for different reasons. At the heavy end of the scale (1-3RM), you fail because you cannot sustain the neural drive (the messages your nervous system sends to the motor neuron in the Motor Unit), not because the muscle is fatigued, there isn’t enough time for that. Up towards the lighter end (15RM or more), metabolic effects (cellular energy depletion and waste product build-up) cause you to terminate the set. In between these two points you get a sliding scale of both.

Is there any point to failure? According to the research, there’s not much difference between getting close and actually failing (Drinkwater et al. 2007,) but failure does negatively affect hormonal and neural status, making inroads into your recovery. Depending on the program you choose, it’s your call.

However, I do think that it is critical to have experienced training to failure as part of your education as a lifter, at the very least as a way of understanding your body and recognizing the difference between when you are giving up and when your body has given up.

Some programs advocate failure. It is the goal. Some push beyond it with rest-pause, forced reps, etc. Some programs avoid failure and some lie in-between.

We recommend stopping when you know another complete rep (or maybe two) isn’t in the cards. Because the load is heavy enough to maximally stimulate the muscle from the first rep and the number of reps high enough to provide the appropriate fatigue, there is no need to eat into your recovery by going to failure.


Based on the research into Muscle Protein Synthesis and Adaptive Remodelling we know that after 72 hours pretty much everything has returned to normal, which gives us a guide as to when a muscle is ready to be trained again. Keep in mind, it is a guide and is not absolute.

Between once every 5 days and twice a week is about right (Wernbom, Rhea et al) if you’re training within the appropriate parameters. Some can tolerate more, some tolerate less, but most of us sit squarely in the middle. As you get very strong, the number of times you can train a bodypart weekly is likely to decrease.

We give you three variants of the program; two where each bodypart is trained on average every 1.5 days and another where you train each bodypart twice a week. Both will get you bigger than you have ever been before, but which you choose is dependent on your time constraints and ability to recover. On the face of it, the more frequent variation is better (because the muscles are being stimulated 25% more often) but if you can’t recover from it, it isn’t better at all.

Spend any time looking into the rep ranges, number of sets and frequency of most popular programs (which I have) and it’ll be pretty obvious that while there are lots of successful and very different looking programs, dig a little deeper and you’ll find they all share the same principles.


Getting really strong (I have no definition, just think record breaking strong) is not a case of simply having big muscles; it’s about thick, strong connective tissue and joints, favorable muscle insertion points and leverage, nervous system efficiency and so on. So not everyone has the capacity to break world records — big deal.

Arguing that getting stronger does not mean getting bigger is forgetting the physiological basis for increasing the cross-sectional area of the muscle (growth) and that is increased strength production. Beyond enhanced nervous system efficiency, strength comes down to structural changes. You are going to need to get bigger to get significantly stronger.

So limit strength isn’t necessarily the goal when trying to get bigger, but getting stronger is. If you don’t get stronger, you won’t get bigger, but opponents of this fact, seem to forget that the 1RM isn’t the only measure of strength. Increasing your reps from six to seven with 200-pounds is getting stronger. Increasing the weight from 200-pounds to 210-pounds for six reps is getting stronger.

If you work to get significantly stronger you will get significantly bigger; it’s the only way the body knows how, but that doesn’t mean strength training. Bottom line — size is a result of long-term strength gains. We understand that, which is why our program emphasizes it.

Get significantly stronger and you will get significantly bigger; it’s the only way the body knows how


Progression is necessary if you want to exceed your current development. Getting bigger means getting stronger and, as we showed earlier, that doesn’t have to mean focussing on increasing your one-rep max.

When you start lifting, strength increases come quickly (or at least they should) and by and large, these increases will occur linearly (i.e. every session you’ll get stronger).

Clearly this isn’t sustainable, five-pound increases on your squat every week would result in a 250-pound increase in a year and within another three years you would be squatting over 1000-pounds. So strength gains become non-linear, you get peaks and troughs, but over time an upward trend is what you’re looking for. Some programs advocate caution, focusing on very small increases on sub-maximal loads allowing for slower more sustainable progress. Bear in mind also that muscular growth, is generally non-linear too. You don’t often see your legs proportionately increasing in size with every addition of ten pounds on the bar.

There are various ways to progress, single, double and triple progression, increasing only the reps, only the weight, only rest between sets and so forth, but I prefer a less formal approach — Autoregulation.

This term may or may not be new to you. It’s meaning is in fact as old as weight training itself. In Mel Siff’s Supertraining he discusses APRE (Autoregulating Progressive Resistance Exercise) a method whereby your next session’s load is determined by an adjustment table based on your current session’s performance. Charles Staley’s EDT is an example of autoregulation, as is Mike Tuscherer’s Reactive Training Manual, but I think ex-Mr. Olympia Frank Zane (in his 1977 Bodybuilding Seminar) explained it best over thirty years ago, when someone asked him, “Do you have a certain poundage you will always try to use each workout?” His response:

“No. It’s all by how I feel. Let’s say I am doing dumbbell presses. Now the first set I’ll start with sixty-pounds for twelve reps, then seventy-pounds for eleven. Maybe to eighty. Now depending on how the eighties feel, I’ll either stay with the eighties and do a couple of sets, or move up to eighty-five or ninety-pounds. IT’S ALL IN HOW I FEEL AT THE TIME. If I am ready for a new weight, then it just happens.”

There are lots of ways to autoregulate, (see the programs referenced above) but for our purposes we’re going to keep it very simple and rely entirely on the cues our bodies give us each time we train. You can either map out progression (i.e. plan to increase the load at a predetermined time), that could be every session, or every fifth week, or you can allow it to happen when your body is ready for it — autoregulation.

An assumption in the predetermined approach is that you can force progression; you can’t. Just because you plan to increase your bench by five-pounds next session doesn’t mean your body will play along. You’ll progress when your body is ready to. All you can do is provide the initial stimulus, eat accordingly and hope your body has adapted in time for the next session.

Planned progression also implies that performance is consistently high, but we all have good, okay and bad days and our performance generally follows suit. With our version of autoregulation we train to the best of our abilities on the day, like Frank Zane explained above, which can sometimes mean performing far worse than the last session but, just as importantly, sometimes means performing far better than expected. Remember it is a trend upwards we’re looking for. You’ll get the full autoregulation protocol, when you get to the HCT-12 Training Program.

Ex-Mr. Olympia Frank Zane – If I am ready for a new weight, then it just happens.


Following on from progression is the subject of periodization. Periodization is planning, planning to train different athletic or strength qualities (strength versus strength endurance versus speed-strength, etc.) at different times without losing (or minimizing the loss of) the training effects of the previously trained quality.

Why? Because the body has a finite capacity for recovery, not every aspect of your sport can be trained with equal focus simultaneously, so you have to plan. Louie Simmons popularized periodization for powerlifters with his Westside Conjugate System.

For our purposes, we don’t need to worry about how our weights work affects our 400-meter sprint time, nor how to plan tapering down to a fight, meet etc. Getting bigger is lifting, which makes things a little simpler. We don’t need to concern ourselves too much with overly complicated periodization.

Our program focuses on 6RM for each exercise. This is the range where the muscle is most exposed to the required stimulus and fatigue. If I had to choose one rep range for the rest of my life, it would be around 6RM. Fortunately we’re not so constrained, and can train above and below this, so we can introduce an element of periodization into the program.

Focusing on the 1-5RM range will get you stronger, making you neurally more efficient and carrying over to the higher rep ranges. As getting progressively stronger is the foundation for growth; this is a good thing. You will, of course, get bigger in that rep range too, so focusing on it for awhile is no bad thing depending on your program. However, we feel that training in the 6RM range that we’ve programmed focuses enough on strength without needing to overlap by going into the lower rep ranges.

Higher reps however, do provide a growth stimulus and improve energy supply to the muscle — also a good thing. They also allow for a break from the heavier weights that 6RM demands, giving the connective tissue (and you in general) a chance to fully adapt before hitting it hard again.

I prefer to refer to this sort of simple periodization in terms of deloads at least in regard to our program. Some programs incorporate deloads but don’t stipulate when you should deload, nor what you should do in that period, leaving it up to the individual. The pitfalls of this approach, are that the very dedicated lifter may by-pass the deload completely, running him or herself into the ground, or that the lazy will look for any excuse to deload. Our program is a little more rigid, enforcing a change in pace.


How long should a training session last?

Well if you’ve followed the guidelines then the length of your session is really dictated by the number of sets and reps you do. Basing it on anything else (i.e. acute and transient hormonal fluctuations) is irrelevant. If you’re not group training, lifting equipped, having to warm-up and load over 600-pounds on the bench/ squat/ deadlift like a powerlifter, and if your focus is on size then anywhere between forty to ninety minutes is about right. Our program can be done in under an hour.

Full Body versus Split

The point is to train the whole body over a given period of time, typically a week. Don’t well-designed Full Body programs do that, and doesn’t a well conceived split?

Both factions of supporters cite imbalances (focus on chest and biceps for splits, and a small arms on Full Body splits), lack of results (most idiots cluttering up the gym are on a split, no really big guys or pros use a FB) but ultimately and as I state in the intro, this is down to user error (lack of consistency and effort). Most people in the gym don’t look like they lift and are by and large going through the motions, irrespective of what approach they SAY they use.

If your goal is size and you are follow a proper program, then a split is the way to go. It allows for the appropriate frequency and spreads the workload across more days, allowing better focus and recovery. Our program is a split.

Exercise Selection

First off there are thousands of exercises to choose from, so there is no way you can use them all, and you could spend every single day for the next few years just trying them out.

Secondly, it should be obvious, that as progression is key, you should be favoring (not completely excluding) exercises that allow you to progress (i.e. shoulder press versus something that for one reason or another you’re simply not going to get a hell of a lot stronger with, such as the lateral raise).

Traditionally, these exercises are barbell or dumbbell based, but the fact is you could do as well with progressively heavier rocks, but they’re a pain to hold and don’t come in small weight increments; so impractical and not versatile. Bars and dumbbells are versatile and adjustable.

Let’s not forget machines either, they allow progression in small increments and the good ones allow a lot of weight and feel really good. And as I said above, tension on the muscle is tension; barbell, rock, tire, machine. If it progresses over time, you’ll grow.

If you’re particularly strong and not concerned anymore with loading 400-pounds on the bench press and just after size then you have paid your dues, a machine might be better. Yes, you are a special little flower after all. This is one of those areas in lifting where you get to say, “I’m different, I prefer Hammer Strength shoulder press to military press, and I feel it more in my shoulders.”

There is no ONE perfect exercise for everyone that will proportionally develop the target muscles, and while any variation of a press (barbell, dumbbell, machine, rock, neighbor), will place tension on the pressing muscles, your special individual body type will determine what pressing muscles are under most tension and which therefore will grow the most.

So after some experience, (and by experience I mean seen significant growth using one approach, not brief passing attempts at lots of approaches), feel free to see which variation of a lift gives you the best effect. Our program is based on compound barbell and dumbbell movements, but you have the option of choosing preferred machine variants.

Isolation Exercises versus Compound Exercises

Again, I’m not fussy. Liberally apply common sense and most of your exercise choices will be compound movements, with some strategically placed isolation exercises. It could not actually be any other way. I doubt you could effectively train the whole body without resorting to compound exercises. If I’m wrong, someone please tell me how?

Should isolation work (or focus work, as you can’t truly isolate a muscle) be excluded? Maybe; if you’re a bewildered novice faced with thousands of exercises, then keeping it very, very simple is best, which is why Full Body approaches are so often advised for beginners.

This leads me on to the asinine argument of functional vs non-functional muscle/strength/exercises. Loosely speaking, the contractile components (myofibrils) make up approximately 80% of the muscle fibre, the other 20% is sarcoplasm; a watery substance comprised of the same sort of stuff required by every cell to function.

You may have come across discussions on myofibrillar versus sarcoplasmic hypertrophy and how bodybuilders tend to be weak and puffy (they are not) and powerlifters dense (sometimes they are, sometimes they are not). Well these two terms are trotted out as a reason for that.

Given that approximately 80% of the muscle fibre is contractile protein, anyone (bodybuilder or powerlifter) whose muscles have grown will have hypertrophied the same tissue. The other 20% is speculative. Aside from one Russian rat model translation, sarcoplasmic hypertrophy does not exist. I’m not saying there isn’t a mechanism for the growth of non-contractile tissue, possibly to keep up with the energy demands of contractile tissue, but as it makes up less than a fifth of muscle fiber and therefore a fifth of your growth potential, I know where I’d focus my time.

If you can point me to a large bodybuilder who is weak relative to his size, then I can point to the same bodybuilder and guarantee he is significantly stronger than when he started — he just didn’t have a great capacity for maximum strength development.

As stated above, it would be the devil’s own job to fully train the body through isolation work only, so beyond that extreme, anyone who is well developed from top to toe, isn’t going to have arrived that way through machine flyes only and is going to be very much stronger than average, very much stronger than when he started and able to express that strength in meaningful/ functional ways such as lifting sofas, shopping, insert spurious “bodybuilders can’t do this activity” here, etc.

If being able to run ten miles, jumping through flaming hoops while bench pressing on the off chance you will one day need to pull kids from a burning building is your goal, or you’re after more non-specific feats of strength then maybe you should be focusing your training on all eventualities. Good luck with that.

In our program we’ll use whatever comes to hand, focusing on compound movements, but not neglecting body parts that respond optimally to a combination of compound and isolation (arms for instance). In the program, we give you clear guidelines about what exercises to use.

HCT-12 focuses on compound movements, whilst not neglecting isolation movements


You made it through!

The lesson you should have learned is that muscle growth boils down to a few simple principles that every program must obey. If you dig deeper and the foundation of a program is not constructed from these principles, you’ll know with certainty that it will not work.

The internal processes of muscle growth are seriously complicated, people devote their lives to it, but the external processes that kick it off, the things in your control can be distilled down to a few principles: Get stronger in the right rep ranges, eat appropriately, commit to the program and consistently work hard at it. This is advice often thrown at the inexperienced or confused but, without context although well meaning, is worthless.

We’ve kept you back long enough. We think you are now ready for our program. If you think you are, then come on through to Hypertrophy Cluster Training – Training Program!

Discuss, comment or ask a question

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