The following is an excerpt from The Overload System for Strength by Christian Thibaudeau & Tom Sheppard.

To better understand why the overload system is so effective, and the reason behind the selection of the methods used in this system, we must talk about the various factors that can increase your strength and, to some extent, your muscle mass.

Getting stronger can actually be accomplished through several different paths. That’s why you have strong people who can have completely different looks. You have massive muscular lifters who are strong, almost skinny wiry lifters who can lift a lot of weight, thick lifters, and lean and hard ones. There really isn’t one type of body that is required to be strong. That might be one of the reasons why training for strength is so cool: While not everyone can develop the huge muscles of bodybuilders (especially drug-using bodybuilders), everyone can get significantly stronger. Throughout history, there have been the more compact and big-boned (not to say rotund) strong lifters, like Louis Cyr (5 ft 9 in. and as much as 330 pounds [150 kilograms]), Paul Anderson (5 ft 10 in. and as much as 360 pounds [163 kilograms]), Doug Hepburn (5 ft 9 in. and as much as 300 pounds [136 kilograms]), or Anthony Ditillo (5 ft 6 in. and as much as 300 pounds [136 kilograms]).

And you also had the mesomorph lifters who were muscular on a big and wide body and seemed to be born to be strong. This body type included Hermann Görner (6 ft 1 in. and over 265 pounds [120 kilograms] in lean condition); George Hackenschmidt, who actually invented the bench press and hack squat (a lean 225 pounds [102 kilograms] on a 5 ft 10 in. frame); Steve Stanko, who at 5 ft 11 in. and 225 pounds (102 kilograms) was both a member of the U.S. national weightlifting team and a Mr. Universe winner; and John Grimek (5 ft 8 in. and 215 pounds [98 kilograms] in lean condition), who was also a member of the U.S. national weightlifting team and a Mr. Universe winner. Heck, you even had ectomorphs (lanky, thinner, with long limbs) develop elite strength, with Bob Peoples (5 ft 9 in. and 165 pounds [75 kilograms]) being a prime example.

The point is that strength can be increased by optimizing several systems; everybody can significantly increase their potential, whereas not everyone can become huge. With the overload system, we are aiming to maximally develop all the facets that contribute to strength, with the goal being to get every individual as strong as they are capable of being regardless of their body structure.

Muscle Mass

All else being equal, bigger muscles are capable of producing more force than smaller ones. As such, increasing muscle mass will get you stronger. However, not everyone is as strong as they look (we will see why in the nervous system subsection). You do have large and muscular bodybuilders who don’t lift heavy. That might be because of an inefficient nervous system, excessively conservative protective mechanisms, lack of joint stability, or simply a choice of training style.

However, anybody who gains muscle will get stronger provided that the other factors contribute to strength do not lessen. The way I like to explain it is to say that your muscle mass represents your strength potential. The bigger your muscles are or get, the higher your potential to produce force is. Whether you are strong or not is a matter of being capable of using a large proportion of this potential. How much of your potential you can use depends on several factors, including neurological efficiency, level of protective inhibition, joint stability, and technical efficiency. Having big muscles is like having a large factory with lots of employees: it certainly should allow you to be more productive, but to do so your employees must work hard and work well together.

Neurological Efficiency

The nervous system, in large part, dictates how much of your strength potential you can use. The nervous system controls how many muscle fibers are recruited, how fast they twitch (firing rate is a huge part of strength production), how coordinated the fibers within a muscle work together, and how synergistically the muscles involved in a movement are recruited.

Let’s get back to our “muscle = factory” analogy. If the factory and the number of employees you have represent your muscle mass, the various neurological factors refer to how well your employees are working. Being able to recruit a lot of muscle fibers and make them twitch rapidly (high firing rate) represents how many of your employees actually show up to work and how hard they work. If you have lots of employees but they are lazy, you won’t live up to your production potential. If your employees work hard but the workers at a similar workstation do their own thing and don’t work well together, you still will not live up to your production potential. It’s the same thing with your muscles: Intramuscular coordination is how coordinated your muscles fibers are when doing a movement. The better their coordination is, the more of your potential you can use.

And even if your employees work hard and work well together, you could still come up short of your potential if the various workstations are not in sync. This is called intermuscular coordination and refers to how well the various muscles involved in a movement are working together.

As you can see, if you want to use a large proportion of your strength potential, you must optimize your nervous system. When it comes to producing high levels of force, you must be frequently asking your body to produce a lot of force. Strength is a skill. You can have the body necessary to be strong, but if you don’t practice heavy lifting, you will never reach anywhere close to your full potential.

Protective Mechanisms

Continuing the factory analogy, even if you do have a lot of employees who work hard and well together, you could still come up short of your production potential. If the supervisors are extremely worried for the safety of their workers, they could impose several security protocols and limit the production speed to reduce the risk of injuries among the employees. This would, of course, limit production in the name of safety. And it’s a good thing. Just like we don’t want any serious work-related injuries, we don’t want to pull or tear a muscle or tendon because we are producing more force than is safe for our body. But when a factory’s supervisors are overly conservative, they could very well limit production potential for no good reason.

It’s the same thing with your body. The muscle protective mechanisms (mostly the Golgi tendon organs) are extremely conservative in the normal human body. They allow the average person to use (under normal circumstances) 30 to 40 percent of their muscle strength potential. That’s why under situations of high adrenaline, you can produce a lot more force than you normally would: the adrenaline doesn’t suddenly add muscle to your body; it inhibits the protective mechanisms and allows you to use more of your strength potential.

Now, the more experience you have with producing force (either from training or physical work) and the more force you are asked to produce, the less conservative your protective mechanisms become. Weight-trained (think “bodybuilding style”) individuals might be able to use 50 to 60 percent of their muscle potential; strength training (more focused on heavy lifting) will increase that percentage even more. In fact, elite strength athletes are likely able to use 80 to 90 percent of their potential.

While any type of weight training will gradually reduce the sensitivity of the protective mechanisms, the heavier you go, the faster and more effective the process is. The caveat is that if the heavy lifting leads to trauma or injury, it could backfire and have the opposite effect. Overload exercises are thus more effective at inhibiting the protective mechanisms because they use more weight than you can use on the full-range movement. And even though you are using more weight, if you are using good mechanics, the risk of injury is actually lower because most muscle or tendon injuries occur when the muscle is in a lengthened position.

Stability

This is actually another part of the body’s protective mechanisms. The more stable a joint is, the more of your strength potential your body will allow you to use. On the other hand, if a joint is unstable, you will be limited in how much force your muscles will be able to produce. To quote the great Fred Hatfield, who squatted 1,014 pounds (460 kilograms) at age 45, “You can’t shoot a cannon from a canoe.”

I see two main types of stability: passive and active.

Passive Stability
Passive stability is created by having, and pardon the scientific lingo, lots of stuff around a joint to create a compression. The compression puts pressure around a joint and stabilizes it. It is kinda like wearing knee wraps around your knees to make them more stable in order to lift more.

What is this “lots of stuff” I speak of? It could be intramuscular glycogen, water, and fatty acids blowing up a muscle to make it bigger and press more against the joint. It could be water outside the muscle, or it could even be fat.

By the way, the main reason that you lose strength on multijoint movements when dieting down is because of this loss of passive stability. When you do a fat-loss phase, you reduce calories and (most likely) carbohydrates. You often decrease sodium intake (not necessarily voluntarily, just by eating less sodium-dense foods). The result is that you lose a little bit (and eventually a lot) of that “lots of stuff.” You decrease intramuscular glycogen, water, and fatty acids; retain less extracellular water; and lose fat around the various joints.

Active Stability
Active stability is when you create a more stable joint by contracting the muscles surrounding the joint. We often talk about “stabilizer muscles,” which is really a misnomer because there is no such thing. Stabilizing (or fixating) is a muscle function, and every muscle is capable of doing that function. Furthermore, a muscle can stabilize in one movement but act as a prime mover in another one. Heck, it can even stabilize in some parts of the range of motion and be a prime mover or synergist in another part!

That’s why movements seen to be working the stabilizers (e.g., isolated rotator cuff exercises) really do have a limited impact on improving your strength potential unless these muscles are inhibited or extremely weak to start with.

There are more effective ways of improving active stability during heavy lifting.

  • Isometric work or stato-dynamic work. This type of workout increases the recruitment of the synergistic and antagonist muscles to create more stability.
  • Lifting under conditions that require a greater effort to stay stable (e.g., tall kneeling overhead press, hanging band technique, loaded carries). Note that making the object you are lifting less stable is more effective than making the base less stable.
  • Eccentric work. When done by focusing on controlling the load (going down slowly), you develop the capacity to maintain tension throughout the range of motion, increasing stability. Plus, an eccentric overload activates the motor cortex more than other types of lifting, which will lead to faster motor learning and a more durable motor pattern.

Tendon Thickness and Resilience

It has long been known that tendons play a huge role in producing strength. Even the old-school lifters instinctively knew this to be true. They might not have known all the reasons why, but they knew that thick, resilient tendons were a huge part of being strong. In many old-school training books, they were typically referred to as “sinews,” and getting them strong was a big part of many programs.

There are many reasons why thicker and more resilient tendons are important for strength production. One reason, first and foremost, is because tendons attach the muscles to the bones that they are moving. We tend to think of lifting as moving a bar (or another source of resistance), but in reality, what we are doing is moving our skeletal structure to produce movement while we are holding an external load. Essentially, your muscles move bones, which creates movement and allows you to complete a lift. The heavier the weight you are moving is, the more force the muscles must create to be able to “pull the bone” and create movement. The more force is produced, the greater stress the tendons are under.

As I explained earlier, the body has protective mechanisms in place to prevent it from tearing itself apart through voluntary actions. I mentioned the Golgi tendon organs (GTOs) that are situated, as the name implies, in the tendons. When the GTOs sense that there is too much tension and force applied to the tendons, they will trigger an inhibitory mechanism that will prevent further force production. It can even go as far as promoting relaxation (loss of force production) through its action on the inhibitory neuron. This mechanism is extremely conservative in a normal individual and is easily triggered by tension or by a rapid and forceful stretch. As you become more experienced with lifting, especially heavy lifting, you will develop some desensitization of the reflex.

Another way of reducing this reflex is to make the tendons thicker and more resilient. Thicker and stronger tendons can withstand a lot more tension and also stretch to a lesser extent. Having thicker, stronger tendons has an obvious positive impact on strength production, but so does having stiffer tendons. A tendon that is more easily stretched will transfer less force from the muscle to the bone because it will dissipate some of that tension through the stretch. To illustrate, attach a rope to a weight. Put the weight on the floor and try to yank it up by forcefully pulling on the rope. It should not be an issue at all. Now try to do the same with an elastic band instead of a rope; it will be a lot harder to get the weight moving. The stretchier the band is, the harder it will be to move the weight. Not to mention that stiffer tendons have a stronger stretch reflex, which can also contribute significantly to force production.

Some people are born with naturally thicker tendons, which gives them a mechanical advantage when it comes to building strength, but you can also develop the thickness of your tendons by using a combination of accentuated eccentric actions and high rep exercises, especially if the high reps work the muscle over the fullest range of motion possible or emphasize the portion of the range of motion where the muscles and tendons are stretched the most.

Adrenergic Sensitivity

This is also a neurological factor, but it is mostly peripheral rather than central. As a brief explanation, adrenergic receptors interact with adrenaline to either activate or inhibit a certain tissue. The beta-adrenergic receptors, when turned on, activate the tissue. For example, if you activate the beta-adrenergic receptors in the muscle, you increase the muscle strength, power, and speed potential as well as muscle tone. If the beta-adrenergic receptors in the heart are activated by adrenaline, your heart rate and heart contraction strength increase, allowing you to deliver more blood, faster. This is useful for physical activity because it sends more oxygen for energy production to the muscles as well as clears out the metabolites (waste products) of muscle contraction faster. If you bind adrenaline to the beta-adrenergic receptors in the brain, you become more motivated, driven, competitive, and aggressive. You also speed up motor programming and muscle fiber recruitment.

Another important thing to understand about receptors is that they can vary in their response to a hormone or neurotransmitter. If a receptor is sensitive, it will have a strong response, meaning that even a small amount of the hormone or neurotransmitter will elicit a strong response (and of course a large amount will lead to an even greater reaction). If a receptor is resistant, it will take a very large amount of the hormone or neurotransmitter to elicit a response.

What’s even more important is that most receptors can be made more resistant (downregulation) or more sensitive (upregulation). The normal mechanism to achieve this has to do with the amount and frequency of stimulation of a receptor. The more often you bind a hormone or neurotransmitter to a receptor, the more it will start to downregulate (respond less and less to the hormone or neurotransmitter). This happens to an even greater extent if the amount of hormone or neurotransmitter is high. On the other hand, you can make some receptors more sensitive by reducing the frequency at which it is stimulated. The beta-adrenergic receptors are especially prone to downregulation. If they become less sensitive, your performance—both physical (drop in strength and speed, lower endurance and recovery) and mental—will drop considerably.

If you constantly “train on the nerve” (to quote weightlifting legend Alexeyev), the risk of downregulating the beta-adrenergic receptors is great. People who train all-out too often (or too often with a lot of volume) may start to see their performance degrade. They can even start to look worse as their muscle tone diminishes, making them look softer and smaller. This is all because they stimulate their beta-adrenergic receptors too much.

That also explains how deloading and peaking works for strength sports. It has very little to do with glycogen super-compensation. What happens is that the pre-contest training will downregulate the beta-adrenergic receptors to some extent. While the muscles are stronger, some of those gains are hidden by the fact that muscles are made less sensitive to adrenaline.

When you deload or do a peak week, you dramatically reduce training stress, which lowers adrenaline and allows you to upregulate (make yourself more sensitive through less stimulation) your beta-adrenergic receptors, which will make you more responsive to adrenaline and allow you to showcase more of the strength you have.

The take-home message is that doing too much, too often, too hard can make you weaker, and it is something that is extremely common among passionate lifters. As you can see, people can get strong several different ways, which explains why strength comes in all shapes and sizes.

We could have easily included technical mastery of the lifts as a way to get stronger. And it certainly is important to be able to demonstrate your strength in a specific lift. It is one of the reasons why Olympic weightlifters can lift two to three times their body weight from the floor to overhead in an explosive action. However, technical mastery does not really get you stronger. It simply allows you to apply the strength you have to complete a specific movement as efficiently as possible. While technical mastery is extremely important ( which is why we have a whole chapter on mastering each of the basic lifts in this plan; see chapters 4 through 9), it is not a physiological key to get stronger.

With all of that in mind and a deeper understanding of the factors that can make you stronger, let’s look at the effect of the various methods we will be using in this plan.

About The Authors

Christian Thibaudeau is a strength and conditioning coach with over 22 years of experience. He has taught seminars in over 20 different countries and has worked with athletes in 28 sports at all levels—high school to professional and Olympic athletes—as well as the everyday lifter. His training has also led him to work with competitors in the CrossFit Games and the Mr. Olympia bodybuilding competition.

Tom Sheppard is head coach at Thibarmy and works with a wide variety of high-level athletes from all backgrounds. His philosophy is based on learning how to use the body as one integrated unit and optimizing athletes’ lifting mechanics based on their body type. This approach has brought him particular success in the sport of powerlifting, where he has produced countless British, European, and world champions and record holders.