High Intensity Training (HIT)

2 How training works

Although all the important components of training have been contained in the story of how Milo became so incredibly strong and muscular, it took more than two thousand years before the components could be properly identified. As a consequence, many misconceptions about training have developed. Some of them are still around today.

Maybe the biggest misconception is applying the idea of “the more, the better” to training. Training is like medicine. You need a certain dose. Once you reach the required dose, the medicine will cause a physiological reaction. Taking more than the required dose is not necessary. In fact, it is even counterproductive and even potentially harmful. This is why every medicine comes with a package insert that informs and warns you of the dangers of an overdose of that medication.

So where does this misconception of more training being better come from? This question can be answered quite easily. In many contexts it is absolutely correct that the more you do the better you become. If you want to be the best piano player you can be, you better play a lot. Playing the piano only twice a week for twenty minutes will not do much to improve your ability of playing the instrument well. This concept even applies to some aspects of competitive sports, at least to a certain extent.

It is true that there are many kinds of sport in which potential success is directly related to the numbers of hours spent. Many competitive athletes follow a high-volume approach when preparing for important sports competitions or even the Olympics and World Championships. In some sports this is absolutely reasonable because preparation for competitions on an elite level consists of two factors:

a) practice

and

b) training.

Practice

When it comes to practicing tactics, moves, games and so forth, the old saying that “practice makes perfect” is definitely true. If your goal is to hit the basket as often as possible, many hours of practice will help you improve more than practicing just a little bit once in a while. If you are the quarterback of a football team, you would do well to practice all the passes and tactics and everything that is needed to be successful. Soccer players spend a lot of time not only practicing the basics like ball control. They also need to practice set pieces like corner kicks, free kicks and so forth, not only to improve their own skills but to learn how to play together successfully as a team. After all these hours of practicing they usually know what a certain teammate will do in the next moment. They know where he will run and where the ball must be passed in order to be received by the teammate.

Even in power sports like weightlifting, practice is a very important factor. The more often you practice a certain movement, the more skillful your movement’s execution becomes and eventually you will reach a level of execution that can hardly be improved even further. Thus, practicing improves performance in many sports. Improvements by practice result from improved skills, experience and coordination. Up to a certain point it is very likely that the more you practice, the better you will become. However, practicing should always cease before exhaustion sets in. No gymnast with exhausted leg muscles would practice their routine on a balance beam and no table tennis player would try practice his serve when feeling exhausted. Throwing the darts can even become quite dangerous to yourself and others once you have lost your concentration and your arms start to shiver due to the amount of throwing that has just been done.

Once you have perfected your technical skills, more practice will not generate better results. A high jumper who already uses perfect form on the Fosbury flop cannot improve his high jump by practicing more often. But stronger legs will enable him to jump higher. And that can only be achieved by training them. Although both terms are often falsely considered synonyms, training is a completely different process.

Practice must precede training

Training must be preceded by successful practice. Take the bench press for example: To gain muscle strength by performing bench presses, the proper execution of that exercise (or any exercise for that matter) must first be mastered. When this is the case, it still takes several workouts before increases in muscle mass can be expected. This may come as a surprise to many trainees who have experienced strength increases right from the start of their training program. And indeed, the greatest increases in strength occur during the first half year of training. This seems to contradict the fact that it takes several weeks of training before muscles grow but there is a very logical explanation. When the body is confronted with a previously unfamiliar stimulus it reacts first by recruiting more muscle fibers for which there has so far not been any necessity to contract. Then, as the training process continues for weeks, more muscle fibers are recruited, which results in increased strength. Once the maximum number of muscle fibers that can be activated voluntarily has been reached and the training program is continued, the only way muscle strength can be increased even further is by hypertrophy in the trained muscle fibers.

Figure 3: Improved muscle fiber activation precedes muscular hypertrophy

Training

Muscle hypertrophy is never the result of practice, it can only result from physiological adaptations.

If an organism is confronted with a stimulus that surpasses a certain threshold level, it will adapt to that stimulus. If you are trying to get a sun tan and expose your skin to a certain level of ultraviolet radiation for a certain amount of time, it will adapt by increasing pigmentation. Once that reaction has been triggered, further exposition to the same stimulus does not add to the effect. In fact it may even reverse the effect by burning your skin so that the tan is lost again.

If your dentist gives you an anesthetic injection which successfully frees you from your pain, a second or third injection will not give you an additional advantage. Giving you dozens of injections may even kill you.

Whenever the human organism is confronted with a certain stimulus above the threshold level the corresponding reaction is triggered. Muscle training is no exception. If a muscle is confronted with a certain amount of tension (about 50-80% of max) for a certain amount of time (about 60 to 120 seconds), the muscle goes into hypertrophy and gains mass and strength.

Stimulus-reaction scheme and ceiling effect

This is called the stimulus-reaction scheme and does not only apply to muscle training but to all kinds of adaptations of the human body to external and internal stimuli. There are two interesting facts about the stimulus-reaction principle and the ceiling effect:

a) Once the reaction has been triggered, it cannot be stopped anymore.

b) Once the threshold has been surpassed, adding stimuli does not fortify the effect.

This is shown by the previous example of the dentist giving a local anesthetic for the nerves of a painful tooth:

a) Once the required amount of medicine numbs the nerve, the process can no longer be stopped and you will be free of pain.

b) Giving you another injection will not make you feel “even more free of pain”.

This also applies to the process of immunization. After a successful vaccination you are immune to the respective illness. Another injection two minutes later will not make you “even more immune”. Neither will a third one another two minutes later. The principle of stimulus-reaction scheme applies to any physiological adaptation. Pregnancy is caused by one single sperm successfully fertilizing the ovum. Additional sperm also reaching the ovum will not make you “more pregnant”.

Probably one of the reasons why High Intensity Training is so popular among medical doctors is that they know about the stimulus-reaction scheme and are familiar with the ceiling effect.

The ceiling effect describes the fact that once the stimulus reaction has been triggered, further stimuli will not add to the effect. If you need 200 milligrams of a certain medication to reach its maximum effect, raising the dose to 300 or even 400 milligrams will not make the medication “work even better”. Actually, the opposite is true. The more unnecessary medication somebody takes, the more side effects are likely to occur, eventually doing more harm than good.

The same applies to training. Once you were successful in stimulating hypertrophy in the trained muscles, the muscles need rest to let the growth process take place. Adding more stimuli (more sets) will not initiate more hypertrophy. It might even interfere with recuperation and, thus, be counterproductive.

Basically, the misconception of more training being better is a transmission error caused by applying a perception to training that has been derived from observations of practice (“the more, the better”). However, such a transfer is inappropriate and unduly.

People who watch a high jumper practice his jumping in the stadium might attribute the strength and size of his leg muscles to his many hours of practicing. What they usually fail to see is that those muscles were not built by practice. They were built in the gym – by training them intensely.

Most people are not aware of this necessary distinction between practice and training and they cannot be blamed for that. Even many exercise professionals and experts have only recently come to realize how important a clear distinction between practice and training is. This lack of differentiation that has been around for centuries is also reflected semantically. Most languages did not even have a word for training and adopted the English word. The word exercise stems from the Latin word exercitium which for centuries has been translated into practice. In German, an exercise is still called Übung, which literally means practice. However, those exercises will only result in physiological adaptations if they are performed with an appropriate degree of intensity followed by enough rest for the body to recuperate and adapt to the stimulus.

In a nutshell, this is how training works. As simple as this may sound, it took the legend of Milo and more than two thousand years for this insight to become generally accepted. At the beginning of the 20^th century athletes still had to go by trial and error in order to find out what worked for them and what did not. However, even if their exercising resulted in improvements, they still did not know what exactly caused these improvements. Was it the kind of exercises? Was it the number of training days per week? The order of exercises? The amount of weight or resistance used? The number of sets per exercise? The number of sets per workout? The rest time between sets? The number of repetitions per set? The speed of each repetition? These are only a few questions about training. Obviously, there are many more and, in addition to that, there are just as many questions concerning the role of nutrition, rest, sleep and so forth. Whenever an athlete made progress, something was obviously working. But it was not known exactly what was working and why.

As a consequence of this lack of knowledge, aspiring athletes did something very understandable. They copied the whole daily routines of successful champions. They copied not only their training routines but also their eating and sleeping habits.

Despite the fact that all the necessary information on training is available to everybody today, many people still do what their ancestors did more than 100 years ago. They copy the training routines of the “champs” and end up training six to twelve times a week like an Olympic athlete, hoping that doing the exact same routine as the champ will put them into the exact same shape as the champ, ignoring genetic factors (not to mention drugs) and not realizing that

a) most of the training articles that are printed in the magazines are grossly exaggerated in order to make the story more interesting and to sell unnecessary food supplements

b) a rather large amount of the “training” time of professional athletes consists of practicing what they need to do in order to perform well on the day of their contest

Understanding physiology

In the 19^th century the German toxicologist Hugo Schulz discovered that the growth of yeast was reduced by large amounts of poison (no surprise here) but was actually stimulated by a small dose of poison. This observation caused some surprise among the scientific community but was then largely ignored for several decades.

During the 1930s two very important observations were published that showed that this principle also applies to human physiology. In an article that appeared in the scientific journal Nature Hans Selye, a medical doctor explained his observation that there are three different stages in which the human body reacts to “noxious agents”, which he later called “stress”.

The other important finding was published in the book The Wisdom of the Body by Walter B. Cannon. Inspired by the works of French physiologist Claude Bernard, he explained that the human body has a tendency to keep up a state called homeostasis (a kind of equilibrium with relatively constant conditions of energy levels, temperature, pH hydration etc).

Small changes do not disturb homeostasis because the body is able to regulate itself. If a person has a daily energy demand of, for example, 2000 kcal, this person will not gain weight when consuming 2050 kcal nor lose weight on 1950 kcal a day. The body can regulate energy expenditure up or down a few percent to keep everything balanced. But if homeostasis is disturbed more severely, a physiological reaction is inevitable.

Selye’s book The Stress of Life (published in 1956 and later translated into 17 languages) explained for the first time that a stimulus is needed which exceeds a certain threshold level to have an impact on homeostasis. When this homeostatic balance is disturbed by any stimulus, the body reacts by trying to adapt to it. Selye also found out that this reaction consists of three different stages: the alarm reaction, the stage of resistance and the stage of exhaustion. Since the body’s reaction to stress can be generalized, Selye called this process the General Adaptation Syndrome (GAS).

Figure 4: The General Adaptation Syndrome (GAS)

Überkompensation

Another observation in this context is the fact that overcoming an illness or disease usually makes the organism stronger and thus less susceptible for future illness. As the German philosopher Friedrich Nietzsche had already written more than a century earlier:

“What does not kill me makes me stronger” (“Was mich nicht umbringt, macht mich stärker”).

Figure 5: Friedrich Nietzsche

In the 1970s scientists discovered that this adaptation mechanism not only applies to the body’s ability to cope with illness but also to any kind of other stressor, including physical exercise.

It was discovered that once the body has recovered successfully from a stimulus, it not only restores the previous status quo but surpasses that point to better cope with future stress that might even be more intense. The process was first described by the Hungarian scientist Nicolai Jakowlew in 1976 pointing out that the body does not only compensate the effects of the particular stressor(s) but goes beyond this by overcompensating to protect the body from negative consequences of the same kind of stressor in the future. German scientists called this Überkompensation. Another synonym is overcompensation, whereas Jakowlew preferred the Latin term supercompensation.

Figure 6: The process of supercompensation

The graph that demonstrates the process of supercompensation does not go with a time frame. That is because different actions take place in the body as a consequence of a training effect. These different actions do not all happen at the same time. Body temperature and hydration, for example, are regulated within minutes after training. Energy balance can also be restored rather quickly but other processes like muscular adaptations take days and adaptations of tendons and bones take even longer.

We know from medical contexts that once a stimulus surpasses a certain threshold, the corresponding reaction is triggered. If the body is then given time to rest, it will adapt to that stimulus in a functional way. Further applications of the same stimulus before the body has adapted, will not add to the effect and might even interfere with the body’s ability to adapt to the stimulus. This is the reason why one sufficiently intense set of each exercise is all that is needed to stimulate muscle gains. The trained muscle fibers then do not need more sets of the same exercise. What they rather need is enough time to rest and grow.

Recently, the model of supercompensation gained a lot of attention. The brilliant scholar and bestselling author Nassim Taleb uses the model to explain his concept of antifragility and points out that there is a lesson to be learned from the body’s ability to supercompensate that can be transferred to other contexts as well. Taleb points out that supercompensation is a natural mechanism of the body to “fight the next war” by overcoming the last one and preparing for the next one. This is how resistance training makes us stronger: “(…) the body overshoots in response to exposures and overprepares (up to the point of biological limit, of course).” [2]

There is no doubt that intensity is the key factor for an increase in strength and muscle mass, not volume. Milo lifted a progressively heavier bull once every day. Lifting and carrying a baby calf twelve times a day would not have made him as strong and muscular. Observations in occupational medicine have shown the same. Intensity, rather than the volume of activities is responsible for physiological adaptations.

Imagine somebody working in an office or book shop from 9 to 5 sorting letters into different filing systems or putting books on different shelves (or a similar kind of work). Lifting 100,000 letters, each weighing 100 grams, adds up to a total workload of ten tons or 10,000 kilograms. Despite the impressive volume of 100,000 repetitions and 10 tons of weight, this kind of “exercise” may eventually give you sore shoulder joints or arthritis but will do nothing in terms of strength and muscle building. On the other hand, lifting 100 kilograms ten times with maximum effort will be more effective for muscle building, despite a total workload of only 1,000 kilograms.

The bottom line is: There is a training threshold. If this training threshold is surpassed, a training stimulus is created. If the threshold is not surpassed, there is no need for the body to adapt. This can be illustrated by another example from the mail delivery business. There are mailmen who walk from door to door for six to eight hours each day, which easily adds up to a walking distance of 40 to 70 miles a week. How many mailmen do you know who can do well in, or even win, a 10,000 meter race without any specific kind of training? Considering the volume of their physical activities, one might think they should easily be able to do that. But it is quite obvious that the intensity of walking is not sufficient to surpass the necessary training threshold. As long as they do not train, simply being active will not be sufficient, not even at a very high volume.

Figure 7: The training threshold

Again, it should be noted that this fact is not limited to muscle training but applies to any aspect of the body adapting as a result of imposed demands.

On a dark and cloudy November day you can spend all day sitting on your veranda without getting a tan. The intensity of sunshine is not high enough to surpass the threshold that is needed for the body to adapt. On a hot and sunny summer day, however, ten to forty minutes of unprotected exposure to the ultraviolet radiation of the sun will stimulate pigmentation in most people. Extended exposure time will not result in a deeper tan but in sunburn.

It is impossible to calculate exactly how many minutes in the sun are needed to get a tan (like X minutes of exposure to Y electronvolt at a wavelength of Z) but it is safe to say that you better get out of the sun when your skin is starting to look a bit reddish.