Is Muscle Shaping Possible?

(Australian Ironman magazine article by Ben Minos – click here to view PDF of actual article)

Concentration Curls for bicep peaks?  How about stretch position exercise for a longer select that muscle belly?  Is it really bodybuilding myth, all can we actually change the shape of our muscles?

Modern science has you believe that genetics is the only factor determining muscles shape.  Truth is we don’t really know how or why muscle growth occurs. Our knowledge and understanding of the pathways involved has grown considerably in recent times, but ultimately, the area of muscle growth is still poorly understood. Could it be that our lack of understanding has blinded us from some
effective training methods and techniques that could help us reach our full potential?  For muscle shaping to be possible, we need to understand and accept a few key notions.

Hypertrophy versus hyperplasia?

The heading should actually read hypertrophy plus hyperplasia equals growth.  It has long been accepted that muscle growth can occur through hypertrophy (an increase in size of the individual fibre),
and for a long period it was thought that this was the only mechanism through which growth occurred. There is, however, substantial evidence that hyperplasia (an increase in fibre number) occurs, and maybe more prevalent (especially in body builders)  than what we once thought.

Several studies have looked at the occurrence of hyperplasia not only in humans, but in animals as well.  You may have heard by now the infamous Jose Antonio study in which a weight was attached to
the wing of a bird.  This study had been completed before, but Antonio’s model differed from the previous models in that his weight was then progressively overloaded.  The total number of stretch days
was 28.  Using this approach, Antonio managed to achieve the greatest gains in muscle mass ever recorded in an animal or human model of tension induced overload.  Not only was there are 334 per cent increase in muscle mass, but up to a 90 per cent increase in fibre number.  Dr. Jose Antonio has completed his doctorate in this area and has been at the forefront in research regarding hyperplasia.

He also points to another study that showed that elite body builders and power lifters had upper arm circumferences 27 per cent greater than normal sedentary controls, although the cross sectional area of their triceps muscle fibers were not different from the control group. Yet another study showed that bodybuilders displayed thigh circumference measurements 19 per cent greater than that of control
subjects, yet the average size of their muscle fibers were not significantly different from the controls.  Some researchers counter these findings by suggesting that many bodybuilders or other athletes have the same sized or smaller muscle fibers verses untrained controls is because of greater genetic endowment of muscle fibers.  In other words, they must have been born this way.  Antonio points out that, if this were true, then the prolonged periods of intense training performed by elite body builders and other strength athletes has produced at best average size muscle fibers.

More research found that swimmers deltoid muscles were greater in size than the controls, even though they had smaller type 1 and IIA muscle fibers. There has been significant research conducted involving direct counts of muscle fibers and they have also shown that both exercises and stretch overload result in significant increases in the number of muscle fibers. The real question then is not whether or not hyperplasia occurs but under what circumstances doesn’t occur? The first assumption on our pathway to muscle shaping: hyperplasia is real and does occur in the human body.  Especially in body builders. We don’t as yet understand why or how it occurs, but there is substantial evidence to support its existence.  It is, therefore, reasonable to assume that hypertrophy is not the only mechanism at play, but can also occur with concurrent hyperplasia of muscle fibers.

The Structure of Muscles

An extremely important, but often surprising fact is that individual muscle fibers rarely run the entire length of a muscle.  Your muscle belly is actually made up of a sequence of 2.5 to 10 centimetres (one to four inch) segments of muscle fibres linked together. If hyperplasia occurs through the splitting of a cell and then the proliferation of a fibre, what would happen if the hyperplasia were to be concentrated in one specific region of the muscle belly?  The muscle fibers found in the middle of the muscle belly and the same as those found at the ends.  What if some of the fibres in the middle of the muscle belly underwent hyperplasia?  Would they magically migrate to another region of the muscle or spread themselves out evenly amongst the other fibres? No.  They were pretty much split and stay in the same area as where they started.  The second point that is critical in understanding how changing your muscle shape can occur is that you can’t simply think of muscle fibres as being synchronous with the actual muscle itself.

Form Follows Function

Another key concept is to understand that a muscle’s structure will always follow it’s function. For years it has been understood that neural adaptations in strength are highly specific to the activity being performed. Why are your physiological or muscular adaptations any different? The S.A.I.D. principle gets thrown around often enough. That is Specific Adaptations to Imposed Demands. Well, how about specific growth occurring in key muscle fibres in response to specific joint angles, muscle lengths and tension demands of the exercise being performed? It’s been shown that the motor units, and subsequent muscle fibres, being hit by one exercise (for example the squat) are not the same motor units and fibres being targeted by another exercise (such as the leg extension). This is why it is encouraged practise by bodybuilders to hit a muscle from a variety of different angles in order to the fullest muscular development. If this wasn’t the case, you would only ever have to do one exercise for each body part to failure in order to get total muscular development. Ironically, this is already the accepted way of training muscle groups such as chest, where we know that if you exercise on an incline, this shifts the emphasis to the upper fibres. Is it unreasonable then to predict that you can emphasise different aspects of other muscles in the body depending on what angle and position you hit it? For example a shortened position for extra demands on the biceps muscle belly?

A cell has the capacity to alter it’s shape as well as it’s volume in response to a need for altered force production. Muscle cells are no different. Unfortunately, to date, little research has been conducted addresssing the questions of cell shape or regional growth.

Does Growth of Fibres Happen in Series or Parallel?

One thing we do know, however, is that a cell’s shape is regulated by work. Remember, a muscle cell is three dimensional; therefor, a cell is abel to double it’s volume either in width or in length. The addition of sarcomeres end to end in series makes the cell longer, whereas the addition of sarcomeres side by side in parallel makes the cell wider.

Again, little research has been done in this area, but, judging by how growth is governed in the rest of the body, we may be able to assume that growth in series and/or parallel may occur, depending on the demands placed on the muscle and the special circumstances in which they occur.

How is Muscle Shaping Possible?

So, what does all of this mean as far as muscle shaping goes? In order to change the shape of a muscle we have to remember:

• sufficient evidence for hyperplasia exists
• muscle fibres are short and are not synchronous with the whole muscle belly
• a cells shape is regulated by work
• growth may happen in series and/or parallel

According to the sliding filament theory, when a muscle shortens beyond it’s optimal length, there is overlap of the contractile units leading to a situation where not as many cross bridges or linkages are able to form. This leads to a decrease in the amount of tension able to be developed and a subsequent loss of muscle force in these positions. This is one of the reasons why you are weaker near the top of a lying leg curl; the hamstrings are in a shortened position.

Adding Peak

How does your body then adapt to produce more force in these shortened positions (neural adaptations aside)? By adding more fibres in the region where the tension demands are greatest of course! Take the concentration curl for example. In this exercise the muscle is in a shortened position, so, as you move through the range of motion, the tension demands are the greatest in the middle of the muscle belly. And, what does it mean to have your body add more fibres ‘in parallel’ in the area where more force production is being demanded? Why you would end up with a bigger biceps peak of course!

Even if hyperplasia wasn’t possible, your body would still preferentially increase the myofibrillar density in the actual fibres where the demand for force was the greatest. Remember that some fibres are only a few cm’s in length. Well the fibres that are concentrated around the centre of the muscle belly would get preferential hypertrophy. Better yet, what would happen if both occurred at the same time? A mix of both hypertrophy and hyperplasia? this is actually the more likely scenario as there is sufficient evidence to support that both occur, especially in bodybuilders.

The key to remember is that adaptation is specific to the area of the muscle where the tension demand is most concentrated. Your body will increase the myofibrillar density (increase fibre size) in the fibres that are congregated around this area, or, will add new fibres (in series and/or parallel) specifically around this critical zone (hyperplasia). With each fibre only being a few cm’s in length, this can change the shape of the overall muscle, So, biceps peakm here we come.

Adding Length

What about stretch position exercises? A similar phenomenon occurs when the muscle is lengthened beyond it’s optimal position. You’re left with a situation where too few cross-linkages are to form because now they are too far apart. So, lengthening the fibres beyond their max position, not enough cross-linkages can bind to generate adequate force. How does your body adapt this time? How about the area of greatest stress i.e. at the ends of the muscle belly, aka the musculotendinous junction? More fibres added at the ends and what does this create? A fuller, longer muscle. There is already evidence to suggest that it is more the eccentric component and stretch position that favours hyperplasia. And it makes sense that this proliferation of cells happens at each end.

The key to this theory is that adaptation will occur more focally and specifically in the area where the tension developed/demanded is greater. In the instance of a shortened muscle, this would be nearer to the centre of the muscle belly. Your body becomes stronger and more efficient at developing tension in this position through hypertrophy and/or hyperplasia of the muscle fibres that congregate in this region of the belly, thus giving you more of a peak, aka biceps peak, from exercises such as concentration curls.

In the case of the lengthened position, where the tension tends to be greater nearer the ends of the muscle belly, at the musculotendinous section, yuor body adapts by the addition of myofibrils and even brand new fibres at these critical zones. What’s the adaptation? A longer, fuller muscle.

This has also been shown in a study where stretching a rabbit’s leg made the mRNA accumulate at the tips of the elongating fibres as they grew longer.

The truth is we don’t know the exact mechanisms or conditions in which muscle groth occurs. We also don;t know if this growth is series or in parallel and what unique mechanisms, if any, stimulate which. As with everything else in the body, form will follow function, so one day we may find that hypertrophy and hyperplasia may be specific to certain demands places on a muscle and regionally specific to these demands.

There is no question as to the importance of genetics in determining muscle size and shape. But that doesn’t mean we don’t possess the potential to change and adapt to enviroment stimuli.

Weight training may provide that special stimulus that allows us to indeed change the shape of our musculature. You may never get the biceps peak of an Arnold, but you may want to give him a run for his money.

References:

Antonio, J. (1997) Muscle Fibre Hypertrophy vs. Hyperplasia Has the Debate been Settled? http://home.hia-no/~stephens/hypplas.htm

Russell, B, et al (2000). Form follows Function: how muscle shape is regulated by work, Journal of Applied Physiology 88:11127-1132.

Siff, M.C. (2003) Supertraining, 6th edition, Supertraining Institute, Denver USA

Stoppani, J (2006) Encyclopedia of Muscle & Strength, Human Kinetics, USA

Editor’s note: Ben is a physiotherapist and exercise physiologist. He owns a personal training business that specialises in Kettlebell Training, Bodybuilding & Nutrition.,

Secrets of Stimulating Growth

(Australian Ironman magazine article by Ben Minos – click here to view PDF of actual article)

How effective would your workouts be if you knew the precise mechanism that stimulated muscle growth?

Imagine you could maximise every rep and every set of every workout to get the most potent stimulus to shock your body into explosive growth. Over the next couple of months we will look at the different theories on what actually stimulates muscle hypertrophy, and separate those that are scientifically sound from those that are not. With this knowledge, you’ll then be armed with the latest scientific information to ensure that you are maximising your muscle growth each and every time you hit the gym.

Is there one best theory of growth?

Talk to a dozen gurus about the single best program for stimulating muscle growth and all of them will give you a different answer. HIT guys will preach that you can stimulate maximal growth with as little as one set to failure. Others say it’s not just the intensity of the load but the amount of work that’s performed with it that counts. Others will say that it’s the time under tension that’s important. Who do you listen to? Is there such a thing as a perfect workout?

Well, let me disappoint you from the start and say that we don’t actually know the exact mechanism behind muscle growth stimulation. That’s not to say that we haven’t been looking. Considering everything that we know about the process and the steps involved, and it is considerable (there are big, muscular physiques walking the earth after all) the actual stimulus for these pathways is relatively unknown. All that we really know is that the genes responsible for muscle growth respond to mechanical stress. That’s the fancy, scientific way of saying that you need to lift weights to get big.

Now that the laboratory geniuses have figured that one out, the race is on to find the best way to make that happen. The truth is there may be more than one way to pull the trigger of that gun. Training to failure more than one way to pull the trigger of that gun.

Training to failure

Is it essential to push the muscles to failure on your working sets? Is this the stimulus that really triggers your muscles to grow?

Some experts believe that unless you’ve pushed the muscle to at least concentric failure on your set, then you haven’t really performed a set at all. It is really those last couple of reps of your set that are the most beneficial and it is these that are responsible for stimulating growth. If the number of lifts you perform in a set is not maximal, then the mechanical work performed during that set is diminished. This means that if a motor unit is not stimulated and subsequently fatigued, then it is simply not trained. And if a motor unit isn’t fatigued, then your body has no reason to adapt and grow.

Let’s have a look at what happens during your typical set to failure. After the first few seconds of your set, some of the recruited motor units become fatigued, so new motor units are then recruited in order to continue. As they also become fatigued, your body tries to recruit more of the motor unit pool in order to cope with the workload demands. Then, once all the available motor units have been activated, fatigue will set in and you’ll reach muscular failure.

Just say your set lasts only six seconds. It will only be the motor units with an endurance time of under six seconds (your fast twitch fibres) that will get exhausted. All the fibres that are actually quite resistant to fatigue (some types of fast twitch and the slow twitch fibres) don’t get maximally stimulated at all. Fast twitch fibres, even though they have been stated to have more potential for growth, are not the most important for the bodybuilder.

Bodybuilders actually have a high proportion of slow twitch fibres that are fatigue resistant, i.e., they display slow twitch properties. Maximal stimulation of these fatigue resistant fibres becomes the most important factor for the bodybuilder. Unless you have a set that lasts long enough to stimulate all of the fibre types, both fast and slow, and unless that set is taken to absolute failure, then you haven’t recruited and fatigued all of the available motor unit pool.

If you haven’t pushed the set to failure, you still have motor units that haven’t been stimulated and as stated before, if a motor unit is not fatigued, then it is not trained. And if a motor unit is not trained, then the subsequent muscle fibres are not stimulated for growth.

This is the main principle behind the so-called high intensity approach to training. If the most important stimulus for growth is pushing the set to failure, then once this has been achieved, no further stimulation is necessary.

Even though the theory is compelling, is it the most important stimulus that triggers your muscles into explosive growth?

Unfortunately, there are a number of factors involved in the fatiguing of a muscle, and it has been estimated that even on a single set to failure, you may only be activating a meagre 30 per cent of the available motor unit pool. So much for maximal stimulation through one set. This can of course be overcome in a few ways, by incorporating such techniques as super setting, forced reps, drop setting, rest/pause, X reps etc.

Another way is to perform more exercises per session to ensure you hit the muscle from a number of different angles to maximise motor unit stimulation. Advocates of this approach usually incorporate one or more of the above techniques into their programs to increase their effectiveness.

Training to failure is one of the more popular theories on hypertrophy advocated in the media, and one that has devotees the world over, especially in bodybuilding circles. But there is another theory behind muscle growth, and this one is the generally accepted theory in scientific circles.

The energetics theory of hypertrophy

At any given instant, each muscle cell in your body possesses only a fixed quantity of energy. This energy then has to be distributed between protein metabolism and mechanical work.

Your body is always in constant protein turnover, meaning it is always breaking down old proteins and replacing them with new ones. This process of course requires energy. Performing mechanical work, or muscle contractions however, also requires energy. During your workout, while you are performing a set, the body is naturally going to divert all of its resources into producing mechanical work. This then leads to an acute shortage of cellular energy for protein metabolism.

This ‘starvation’ of energy that occurs during strenuous activity is thought to be the trigger for the subsequent ‘binge’ (called supercompensation) that takes place during your rest period between workouts.
It’s much like a crash diet experience: you lose some weight, then after you come off the diet, you end up heavier than before? Think of this on a smaller scale happening to your muscles as a result of your workouts.

This follows a similar and more positive line of thinking that bodybuilders have been preaching for years. Your workout needs to perform enough work to cause sufficient breakdown of muscle tissue and then your body needs to repair itself during your rest and recovery days. Does the saying ‘you don’t grow at the gym, you grow during rest’ sound familiar?

So, the trigger for growth and the subsequent amount of supercompensation that needs to take place is dependant upon how much ‘work’ is performed during your workouts. Quite simply, the more work you perform, the more muscle breakdown, the more compensatory growth takes place to deal with this increased stress. That’s why the volume of work as well as progressive overload from workout to workout is so important for continued success.

This theory doesn’t discount the all-important factor of intensity however. It is definitely acknowledged that there must be some ‘critical threshold’ that must be achieved in order to provide a potent enough stimulus for all of this to occur.

The weight needs to be big enough to cause a significant shortage of energy (muscle breakdown), but small enough so that enough work can be performed at this weight.

Too big a weight and only a small number of reps can be performed; too little a weight and a lot of work can be performed without any significant damage caused. Although we don’t know what this critical threshold is exactly, it is generally accepted that it is somewhere in the vicinity of around 70 per cent of your 1RM. This would be around your 10-12 repetition max for most people.

Therefore, it’s not only the force that the muscle produces (intensity) but also the amount of work performed (volume) that is crucial. Maximising both intensity and volume are critical for growth!
As stated in the last section, if the number of lifts performed in a set is not maximal, then the mechanical work diminishes somewhat. However, if the amount of work is relatively close to maximal values, then the difference is not really crucial.

Let’s say you lift a weight 10 times, but you could’ve really reached 12. There isn’t really that much of a difference as far as degradation and stimulation goes! This is also compensated for by shortening rest times between sets. That’s why bodybuilders have shorter rest periods than the more traditional strength type of lifting sports such as powerlifting.

This is the more traditional approach to bodybuilding, where volume is just as an important factor as intensity. Bodybuilders will generally perform a lot more volume per session than strength athletes who focus mainly on the intensity side of the equation.

The take home message for all of you out there? If you are not pushing the set to absolute failure and beyond (i.e., HIT style), then you are going to have to perform more work in order to stimulate those fibres and perform enough work to squeeze out an adaptive response (i.e., increase the volume).

Time under tension

Time under tension theory states that the number of individual reps that you perform is not of great importance, after all, your muscles can’t count. Rather it’s the time that the muscle stays under tension that’s the more important factor.

You’ll obviously still need to be lifting some respectable weights, but just as long as you are able to perform enough work and keep the muscle under tension for at least 20 seconds and up to around 60 seconds, then you’ll see growth over time. As you can see, this is quite a high range and the intensity of the load would vary quite a bit.

Let’s have a look at two examples. Just say you were squatting 100kg. On one set you completed five reps with a 2-0-2-1 cadence, which means that you took two seconds to lower yourself, no pause in the bottom position, two seconds to drive up and one second pause at the top. With each rep taking five seconds, this adds up to a total time under tension of 25 seconds.

Then, on another set, you perform squats again with 100kg, but this time, you completed 12 reps with a 1-0-1-0 cadence, that’s a one second descent, no pause, one second ascent, no pause at the top. This set would take you 24 seconds, a similar time under tension.

Now, this theory states that if the weight is the same, and the time under tension is the same, then the training effect will be the same. Now, without discussing the science behind it, I hope that you can appreciate that the training effect of the above two examples would be dramatically different from each other.

There looks to be more importance to stimulating hypertrophy, than just keeping the muscle under tension for some designated time period. When approached from a different angle, however, this theory can be construed in a slightly different manner. At the end of the day, it is really stating what the above theories have already told us: you just need to lift a heavy enough weight, but be able to perform enough repetitions with it to make any significant difference to your body.

So what really triggers muscle growth?

The main triggers for muscle growth from all of the above theories can be summed up as follows:

• Intensity of the load: you need to choose a weight that will cause activation of a large amount of the motor unit pool, but light enough to allow for sufficient work to be performed with it.
• Achieve muscular failure: this allows maximal activation of the available motor unit pool and ensures you are maximally stimulating as many muscle fibres as possible to induce a training effect.
• Total amount of mechanical work: you need to perform enough reps per workout to induce sufficient breakdown to allow a large ‘rebound’ effect during your rest periods.

The main trigger to stimulate hypertrophy therefore becomes using a weight above a certain critical threshold, say around 70 per cent of your 1RM, trying to activate as many muscle fibres as possible, and then ensuring that the set lasts long enough so that you have fatigued these fibres and performed enough work to elicit a training response.

You can provide this stimulus by performing fewer sets at a high intensity, or more sets at a moderate intensity. You can also use set extending techniques to push past short-term fatigue such as drop sets, rest/pause and forced reps. Not only will this ensure that you are tapping into more of the motor unit pool, but this will again increase protein degradation beyond what the body is used to and again stimulate super-compensation.

All of the above theories stimulate growth, so you should still get results regardless of the theory you subscribe to. Just don’t believe anyone who preaches that they have the one magic answer to the great hypertrophy problem.

Next month, we’ll explore other factors that contribute to stimulating muscle growth and how you can achieve maximum effectiveness in your workouts. We’ll uncover some of the lesser-known theories that, on their own, may not be the most potent stimuli, but when teamed up with the theories covered in this issue, make for formidable growth.

Multiply Your Mass With 2 Types of Muscle Growth

(Australian Ironman magazine article by Ben Minos – click here to see PDF of actual article)

With so much focus on mass and muscle hypertrophy, cutting-edge nutrition approaches and the endless supplement varieties, why are we still so very general in our approach to training?

Three sets of eight reps; it’s the usual advice, trying to pick a weight that allows us a minimum of six reps and a maximum of 12, hopefully reaching concentric failure on the last rep. This is the best rep range for building mass, or so it has been preached for years.

You and I both know that the body will respond completely different to a stimulus that allows only six full reps, compared to a weight that lets you pump out 12. The weight is different, the stress on your muscles is different and the time under tension is different. In fact, the type of growth that you’re stimulating can be quite different.

What most books and articles fail to mention as well as the gym rat, who claims to be the expert in all things mass, is that there are in fact two different types of hypertrophy, two very different ways that you can increase the size of your muscle fibres.

The problem for most people is that when they train, they’re (unknowingly) focusing on only one type of hypertrophy. Think about it, if you’re only stimulating one type of hypertrophy, you’re only getting half the picture, meaning that you’re only getting half the growth. So, if you want to effectively double your chances of building some serious mass, you’ll need to understand some key concepts.

Multiply your growth

Hypertrophy can actually be classified under two different types: myofibrillar hypertrophy and sarcoplasmic hypertrophy. Myofibrillar hypertrophy, often termed functional hypertrophy, is an increase in the muscle size by an increase in the number and size of the contractile proteins of the muscle. This form of hypertrophy is accompanied by an increase in strength.

Sarcoplasmic hypertrophy, or non-functional hypertrophy involves an increase in the muscle size by increasing the size of the sarcoplasm or non-contractile component of the fibre. Increasing this component won’t lead to any increase in tension that can be developed, therefore, you’re not actually getting any stronger, even though your muscle is bigger.

Speak to most people, even personal trainers, and they’ll tell you that a stronger muscle is a bigger muscle. If you get stronger you get bigger right? Well, not always. Why do you think bodybuilders are among, if not the biggest, most muscular athletes in the world, but aren’t necessarily the aside, an increase in sarcoplasmic hypertrophy can account for much of this deficit.

So what exactly are these different forms of hypertrophy and how can they be maximised into your training to give you the most developed, muscular physique?

Myofibrillar hypertrophy

Don’t let the name scare you, all this means is that the muscle fibre has increased its size by increasing the density of the myofibrils, the scientific term for the contractile proteins in your muscle.

Your muscle is made up of different substances. The functioning parts of the muscle – the parts that are actually responsible for producing muscle force – are made up of contracting proteins. These parts of the muscle fibre are called myofibrils. If you increase the number and size of myofibrils within the fibre, two things happen. One, you’ve obviously now grown bigger, and two, because the myofibrils are responsible for generating tension in the muscle, the muscle can now generate more force as there are more units to contract. And this of course leads to an increase in strength. So, think of myofibrillar hypertrophy as an increase in muscle size that coincides with an increase in strength.

That is why this form of hypertrophy is often called functional hypertrophy. For this reason, it’s the form of hypertrophy that sports people are most concerned with, as there is no size increase without strength benefits. More specifically, you are not putting on any unnecessary bulk.

It’s important for some athletes to be as light as possible, but also as strong as possible. Neural adaptation aside, this is the most important form of hypertrophy for athletes. It is also a critical form of hypertrophy for bodybuilders as it also increases the density of their muscles. So if you have larger myofibrils and more of them per unit area, you have a denser, harder muscle.

Powerlifters are the perfect example. They are renowned for their dense, thick physiques. They achieve this by lifting heavy, and any form of hypertrophy that occurs is purely functional. They don’t want to get bigger for the sake of it; they want any increase in size to be accompanied by an increase in strength.

Look at the physique of a bodybuilder such as Johnnie Jackson. Johnnie Jackson is infamous for the amazing strength he possesses as a bodybuilder. How did he build this hard dense physique? Through heavy lifting and focusing on the basic compound movements.

The take home message for you is that if you want to build thick, dense, hard, quality muscle, then focus on building myofibrillar hypertrophy. You increase the density of the muscle by increasing the density of the contractile components, and the only way to do this is by lifting heavy and lifting hard. No, we’re not talking about heavy bicep curls. The best way to stimulate functional hypertrophy and strength is to focus on your heavy, basic compound lifts: that is, squats, deadlifts, presses and chins.Now that you know the science of why, never neglect your compounds.

Myofibrillar hypertrophy is best stimulated with heavier weights and lower repetitions, so we’re also not talking about sets of 12-to-15 reps here. Keep the reps lower (four-to-eight) and your sets a little higher (four-to-six) in order to achieve some meaningful strength and size.

Sarcoplasmic hypertrophy

Sarcoplasmic hypertrophy is completely different. With this form of hypertrophy you can actually increase the size of the muscle fibre without getting any increase in strength.

The sarcoplasm of the muscle is a gooey, fluid filled matrix that occupies the muscle cell and is made up of substances such as intracellular fluid, mitochondria, stored substrates such as carbohydrates and fats, among other things.

For our intents and purposes, just think of the sarcoplasm as the part of the muscle fibre that doesn’t contribute to the force production of a muscle contraction. It’s all the other substances that occupy the muscle cell that don’t directly contribute to force production.

By increasing the amount of sarcoplasm in the muscle you can actually have a bigger muscle without increasing the number of contractile units within the fibre. If the number of contractile units stays the same, but the sarcoplasm increases, the relative density of the muscle actually decreases. You have now actually decreased the muscle cross sectional area, so you are left with a bigger muscle that hasn’t gotten any stronger.

This is why bodybuilders are often chastised for having ‘California muscle’, all show and no go. They possess more size than the average person, but not the absolute strength to match their size. But as we all know, bodybuilders aren’t powerlifters, and the weight you lift doesn’t matter when you’re up on stage posing. As a good friend of mine always says, “no one cares how much you deadlift at the beach”.

Bodybuilders should be praised for discovering how to maximise hypertrophy through all different methods and not just the one-dimensional approach of ‘you must get stronger to get bigger’.

Obviously sarcoplasmic hypertrophy is not ideal for the sportsperson or athlete. Increasing bulk with no gain in strength or performance is not desirable in most sporting endeavours, so if you’re training for athletics, this type of hypertrophy may not be for you.

For the rest of you who are seeking a bigger, more muscular physique, this form of hypertrophy must be maximised along with myofibrillar hypertrophy if you want to sport the most masculine and shapely physique you can.

You can manipulate sarcoplasmic hypertrophy through a number of different methods. Unfortunately, we aren’t able to cover them all here, but using techniques such as drop sets, extended sets and higher rep training, can also have a significant effect on sarcoplasm. One of the better-known examples of transient sarcoplasmic hypertrophy is when you get a really good pump. Blood flow is increased to the muscle, the capillaries fill up with blood, blowing your muscle up like a balloon and forcing some fluid from the blood and extracellular fluid into the muscle fibres. The volume of the sarcoplasm has increased (sarcoplasmic hypertrophy), your muscles are bigger, but aren’t any stronger.

If you want to train effectively for some sarcoplasmic hypertrophy, keep your rep ranges a little higher e.g. around the nine-to-15 mark, even going as high as 20-to-25 on some exercises and muscle groups. Sets may be a little lower to accommodate for the increase in volume.

Along with training techniques, the sarcoplasm can also be influenced by a number of other factors such as nutrition and supplementation.

It is often stated that creatine can dramatically add weight in the initial stages of loading through intracellular fluid retention. So not only does creatine assist in myofibrillar hypertrophy through an increase in strength, it also has a profound effect on sarcoplasmic hypertrophy through increasing the amount of intracellular fluid.

For every gram of carb that your body stores, it also stores three grams of water, so carb loading can often have a profound effect on increasing sarcoplasmic hypertrophy.

Maximising each form of hypertrophy

The most obvious way of maximising each of these is by not getting bogged down into the three sets of eight reps mentality, and experimented with different training techniques, rep ranges, intensities and supplementation.

With the difference between these two types of hypertrophy, you can see that the stimulus required to maximise both varieties will be quite different.

The main guidelines have already been detailed, but just to recap: for myofibrillar hypertrophy you should look to have a good blend of heavy compound exercises with lower rep ranges focused on building functional strength.

To maximise the sarcoplasmic component you should also incorporate a number of other ‘traditional’ bodybuilding techniques such as high rep sets, drop setting, supersetting, and x-reps. Look at various forms of supplementation and keep your nutrition sound and pretty soon you’ll be training just like the pros.

The bottom line is, you can’t expect to train with one type of training technique and demand that it be the ultimate way to stimulate growth. It should be obvious to you now that there is no one best method to stimulate complete growth. If there’s more than one way for your muscle to hypertrophy and get bigger, it’s going to require more than one type of stimulus.

Make sure that you focus on your heavy compounds for each body part, but also back that up with isolation movements, hitting the muscle from different angles and with a variety of bodybuilding exercises and training techniques.

Don’t get me wrong, it’s not as though both of these types of hypertrophy are mutually exclusive, meaning that the two different types don’t happen in total isolation. But you can change the relative focus of the type of hypertrophy you stimulate by changing the relative focus of your workout parameters.

Attack your growth from all possible angles, with as many different training parameters as possible, don’t just slip into a rut of the same routine. The most effective bodybuilding programs are ones that maximise and stimulate all areas of growth, and this is accomplished only through consistently exposing the body to different stimuli and variations in exercises and training techniques.

If you only use one type of training, you’ll only get one type of response. You want maximum muscle and more mass? Then take action, mix up your training, and double your chances of getting huge.

Maximal Stimulation For Maximal Growth

(Australian Ironman magazine article by Ben Minos – click here to view PDF of actual article)

How inefficient would your training be if you were only recruiting a fraction of all your available muscle fibres? Well, many of you are.

We all know that a muscle cell can’t grow if it is never properly stimulated. Many of you, unknowingly of course, are probably not even tapping into most of your muscle fibres when you train, meaning that you are only getting partial muscle stimulation, and therefore, only part of your potential growth.

It doesn’t matter how hard you push and how much weight you lift, if you only activate the same muscle fibres every session, you aren’t going to get near as much growth as if you tapped in to all of the available fibres.

Bodybuilding great Milos Sarcev has a popular saying: “Partial range of motion equals partial development; full range of motion equals full development”. I’m going to take it one step further. Partial stimulation of muscle fibres leads to partial growth; maximal stimulation of the muscle fibres equals maximal growth. If you want maximal growth, then you need to find a way to stimulate and activate all possible muscle fibres.

What is a motor unit?

A motor unit is considered the functional unit of a muscle and consists of a nerve and all of the muscle fibres that the nerve innervates. Each muscle fibre, however, is innervated by only one nerve branch. That means that the only way that a muscle fibre can be activated is via the activation of its corresponding nerve branch. A nerve may supply only a small number of muscle fibres, while another nerve may supply thousands of muscle fibres. But, each muscle fibre is only ever innervated by one single nerve branch.

This is an extremely important concept. It’s only when the nerve is stimulated that its corresponding muscle fibres are able to contract. Each motor unit acts on an ‘all or nothing’ principle.

Think of it as a light switch in your house. All the electricity comes from the same source, but a light only switches on when you turn on its activating switch. It doesn’t matter how hard or soft you flick the switch, the light either switches on or off. The most important point concerning the human body is, you can turn on the kitchen and bathroom lights all you want, but that still doesn’t make your bedroom light switch on, and if your bedroom light is never switched on, it will never get bright.

Specificity of motor unit activation

Although we now know that the only way for specific muscle fibres to get activated is to stimulate the specific motor unit that supplies those fibres, there’s still more to this story.

Motor unit activation is very specific to the actual movement that is being performed. Motor units behave in a specific way that is the same for every person. Firstly, they are recruited in order from smallest to biggest. Some motor units may be made up of a few hundred fibres, while others top up into the thousands. And, it’s always the smaller ones that get activated first, and if the demands are great enough, the bigger ones are called into play. Your body wants to be as efficient as possible, so it will only use just as much force as is necessary to carry out an action.

Motor unit activation is also very specific to the type of movement being performed and the manner in which it is carried out. This is referred to as the specificity of motor unit activation, and it is a very important concept when you look at training for various sports.

Different joint angles, different movement patterns etc., all equal different motor unit activation, which in turn means the activation of different muscle fibres. Athletes need to mimic movement patterns in their chosen sport as incorrect training can lead to alterations in neural activation, timing and patterning, and can cause a subsequent decrease in performance.

Athletes need to mimic the same neural pathways, the same metabolic processes, the same movement patterns, and speed of movement that they encounter in their specific sporting situation. That’s why you never try to improve your golf swing by swinging a heavier club; this will actually cause an alteration in the neural pathways activated. The key word I used was mimic. You must imitate the movement patterns, not simulate.

You should always treat strength training as a skill. The more you practice, the better you get. Strength is very specific. The goal of the strength athlete is to repeatedly mimick the movement pattern of their sport so that they become more efficient with that movement. They ‘groove’ the right action by consistently stimulating the exact same motor units in the exact same way, every single time.

If you make minor changes to even your foot position or grip width, or wear different shoes, use lifting straps or a lifting belt, this drastically alters your neural recruitment pattern and can actually lead to a decrease in performance. This is why you don’t see sprinters training on a bike, or Olympic lifters doing a lot of leg presses. They would activate a completely different set of motor units and train a different set of muscle fibres than what they use in their sporting situation. What a waste of time!

Why Bodybuilders need to learn the rules… and do the opposite!

There’s a great difference in training for a neural adaptation (athlete) compared to training for a metabolic or physiological adaptation (bodybuilder). As a bodybuilder, your main goal is for complete and optimal muscular development.

From the above discussion, you can see that if you perform, say, the bench press, the exact same way with the same grip width, always with a barbell, with the same speed, in the same rep range, to the same spot on your chest, with the same groove over and over again, you will only activate a certain neural pathway, and therefore, only a certain number of motor units will ever be activated.

If motor unit activation is so specific, then the muscle fibres that you subsequently activate are very specific also. Therefore there is an incomplete muscle fibre activation. You have all of these other muscle fibres belonging to different motor units that never get properly stimulated at all. You have a goldmine of potential growth just waiting to happen in fibres that you have never even tapped into.

The problem is, a lot of bodybuilders get caught up in the above scenario, usually out of habit, maybe out of laziness, or quite simply, they just don’t know any better. Most are too concerned with ‘how much they bench’ with little concern as to whether or not it is stimulating the most amount of chest fibres to maximise growth.

If you’re like most, you’ll use the same exercises, the same grip, the same weights, the same reps and the same equipment, workout after workout. This leads to the same motor units getting activated, which equals the same muscle fibres getting stimulated in the same way, meaning no new meaningful gains in these activated fibres and absolutely no activation in the other unstimulated fibres. Again, great if you’re a powerlifter looking to specialise in a certain lift, but it may not be the best approach if maximal muscle gain is your goal.

Remember, you need to at least switch the fibres on if you ever want to stimulate them to grow. Don’t fall in to the same trap that everybody else does. Don’t do the same old exercises in the exact same way on the same pieces of equipment every workout. If you do, you’ll have an untapped resource of muscle fibres that will never get stimulated. If these motor units remain untapped, that means that you’ll never stimulate growth in these fibres, which means that you’ll have substandard development and will never gain your maximal potential in size and strength.

What’s the solution?

Well, now that you understand the above principles, you can go ahead and exploit them.

To get maximal stimulation of more motor units, and therefore, more muscle fibres, you can vary bench heights, use different pieces of equipment, change grip positions and widths, use a belt, no belt, straps, no straps, raise the heel in squats, don’t raise the heel, change your foot position, change your shoes, don’t wear shoes… the list is endless. Even just a minor variation of your foot position can drastically alter the neural pathway used to perform a squat.

This would mean different motor unit stimulation, which equals different muscle fibres getting stimulated, which would lead to increased overall development. A whole new bunch of motor units (new muscle fibres) will get activated: ones that you were potentially missing out on before. This is great news, especially for those of you who may have stalled with their gains in either size or strength and are sticking to the same old routine and exercises.

Let’s use the squat again as an example. You could change the bar position, high bar, low bar, back squat, front squat, Zercher squat, hack squat (a true hack squat, not the machine). You can also change your foot position. You can elevate your heels up on to a block, you can point your toes in or out, you can position your feet close together or wider apart. You can even change your foot position with a concurrent change in bar position. All of a sudden a whole new world opens up to you with literally hundreds of combinations and possibilities. And with each new possibility comes a whole new variation in motor unit activation, resulting in different fibres being stimulated.

And you know what? It will provide you with a new mental challenge – a new goal to reach for. Just try and squat with your heels up and the bar slightly higher on your shoulders; immediately you’ll have to drastically decrease the poundage lifted.

You can also use different pieces of equipment such as smith machines, plate loaded, pin loaded, dumbbells, barbells, kettlebells… the possibilities are endless.

So now you’re on your way

There are a few caveats to the above. For example, I don’t just simply use variety for variety’s sake. It still has to be part of a properly planned program and implemented according to your individual goals. Another thing to remember: variations can be a great way to work on your weak points, but never at the expense of overall development. Become proficient in your basic lifts first – did I mention the squat? Then you can play around with some variations.

The bottom line is, use the laws of muscle stimulation to your advantage. You need to train for maximal muscle stimulation in order to stimulate the maximum amount of muscle growth and get the most complete, all round development. The only way you can do that is to exploit the above principles.

For maximal fibre stimulation and growth, you must hit your muscles from every conceivable angle and with every variation with a full range of motion. In doing this, you will ensure that you activate as many different motor units as possible and stimulate the maximal amount of muscle fibres for maximal muscle development.