he first part of this mini blog post series dealt with the theoretical basis of antifragility and how this is also reflected in the adaptability of humans. The tendency of our body to overreact (#Dramaqueen) to external stressors has resulted in people being able to colonize every climate zone on this planet successfully. If you want to read more about it, here is the first part.
This second part is primarily about understanding the relationship between the body's stress reactions, for example in response to training and the resulting adjustment. Equipped with this basic biological understanding, we can then enter the final discussion of why we have made it our mission to enable and perfect "High Intensity Training" for everyone.
Training above a certain intensity threshold can also be called a stressor on the human system. In order to understand how sport or high intensity training works for us, we first have to better understand stressors and the stress response of our body.
Every living being reacts to stressors and thus adapts to its environment. For a unicellular bacterium, this may mean that it has too little food and therefore goes to sleep. Vertebrates like us humans are complex organisms with muscles that consist of billions over billions of cells. Since we move with muscle strength, a complex structure of nervous system and energy supply has formed to control our muscles. For vertebrates, a stress response is usually associated with the mobilization of energy for our muscles.
An external stressor does not always have to be a direct muscle stimulus (strength training), but can also be cold or heat exposure, lack of food or oxygen. But here, too, our energy systems and muscles are usually involved in order to react to the stressor.
The concept of allostasis is interesting in order to better grasp stress and stressors. The body reacts to a stressor with many different adaptation mechanisms and the interaction of these leads to the exponential reaction described in part 1 .
Our brain is the control agent that coordinates all changes in our entire body, including changes in behavior. Let's take oxygen deficiency as an example. Our reaction to it is not one-dimensional. This means that a lack of oxygen not only leads to a higher respiration rate, but also to many other adaptation reactions. If we hold our breath, we have no respiration rate at all. To do this, the heart rate and blood pressure are reduced, as is the energy production, so that less oxygen is used. If we get air again, the respiratory rate rises above a normal level and the heart rate and blood pressure rise in order to quickly transport the oxygen back into the cells. And these are just a few reactions which were picked out here. The direct reaction of the body aims to regain balance or sufficient oxygen saturation (homeostatic balance). However, the body does not stop there. It also adjusts the parameters of the homeostatic balance, i.e. what should be the new level for optimal oxygen saturation. For example, it increases the general oxygen saturation in the blood with more red blood cells, so that the body can withstand such a stressor the next time better and, if necessary, the air is held even longer. The long-term response to a stressor is therefore adaptive.
This simple example shows how complex these relationships are. Research is currently using the allostasis theory to describe the adaptation mechanisms of complex organisms to changing environmental and living conditions. Our body is basically able to adapt to stressors in response. And not only that, the body will adapt beyond the stressor to be more than up to the same stressor the next time.
Stressor and stress response: A stressor is actually nothing more than an exogenous shock to which our body has to respond with a coordinated response (allostasis). In addition to primates, we humans are one of the few species that can create pure mental stress, for example fear of job loss. A zebra would never think of that . But let's not be fooled, psychological stress causes the same stress response as physical stress. We rightly say I'm about to explode when someone gets us upset. Of course, this means the pulse response.
A stressor in vertebrates (and therefore us humans) primarily refers to the rapid mobilization of energy for our muscles. A stressor is therefore a kind of short-term crisis or emergency from which we have to free ourselves ("fight or flight"). The reaction to this is in particular the rapid mobilization of energy and at the same time an inhibiting of energy storage. Glucose and the most easily available form of proteins and fats are released from fat cells, liver and muscle so that they are available as energy for the muscles that are currently needed. In a crisis, the energy supply should of course take place as quickly as possible. Therefore, the heartbeat, blood pressure and respiratory rate increase in order to be able to quickly transport nutrients and oxygen into the muscle.
Intensity & adaptation: If a stressor is strong enough and thus challenges our system, a stressor leads to an adaptation reaction. Our body wants to be better equipped for the next stressor of this form. The higher the intensity of the stressor, the more the body feels the need to adjust the homeostatic balance. The intensity must not be so high that the organism breaks (acute trauma -> injury, death of the organism), but optimally leads us to our performance limit in order to cause the maximum adaptation reaction. But fewer muscles can also represent a new homeostatic balance for the body. If we do not give our body stressors with sufficient intensity, not only does adjustment not take place, but the systems are even broken down. This is because the body performs an eternal balancing act between adaptation (for example by more muscles) and energy saving (for example by fewer muscles). A holdover from our evolutionary past that is responsible for people having to do body training at all.
Maintaining strong muscles and a strong cardiovascular system is a luxury for our body that consumes countless calories a day. What could easily be fatal in our evolutionary past. Our body therefore only maintains the muscles when they are needed. Stressors signal the body whether we need our muscles or not. When we just laze around and have no stressors, our body builds back muscles and the necessary support systems (capillaries etc.). This means that our body needs stressors with sufficient intensity to improve the energy systems, for example, by optimizing glycogen stores or better capillaries for the transport of oxygen and nutrients. The heart muscle gets stronger to pump our blood faster and more efficiently through the blood vessels the next time. The damage to the muscle fibers due to high-intensity training also leads to the fact that additional muscle fibers are built up.
However, a stress response is always a reaction to a short-term crisis or emergency situation. Therefore, the direct stress response is usually short-sighted and inefficient and this is associated with high energy costs. In a nutshell, when the lion chases me, the direct situation has priority over the long-term. That means something like: I first have to ensure survival before I can deal with long-term issues. Otherwise there will be no longer the longterm perspective to take care of ;-) But what actually happens in an emergency: I see a lion and I am terrified. Stress hormones are released and activate the sympathetic nervous system (“fight or flight”). Heart rate, blood pressure and respiratory rate increase. I run as fast as I can and I don't care that the rising blood pressure is affecting my cell walls. And I am definitely not concerned with my family planning or stopping so that my digestion works properly. The short-term damage to the stress response is not a major problem and even triggers a positive adaptation reaction, Assuming we don't have such stressors too often and our body has time to recover from it, fix everything and then optimize itself. But if our body experiences an emergency every day, it will pay its price. One also speaks of an allostatic overload, which leads to wear and tear.
“Stress responses are generally short-sighted, inefficient, costly things our body has to respond to in an emergency. If you experience an emergency every day, you will pay the price”
— Robert M. Sapolsky, Neuroendokrinologist
The direct stress response can harm our body if it is activated too often or chronically and the body does not have enough time to recover and adapt. Literally: “Death by a thousand cuts”. If you constantly mobilize energy at the expense of energy stores (fat cells, muscles, liver), you never store additional energy. The body gets tired faster and the risk of developing diabetes even increases.
The consequences of chronic activation of the cardiovascular system are similarly harmful. Hopefully, if blood pressure rises to 180-100 to escape from a lion, it will ensure our survival. However, if your blood pressure constantly rises to 180-100 because your boss or colleague is constantly driving you crazy or you exercise way too much in the high-intensity area, then your cardiovascular system is heading for a disaster. The constantly increased blood pressure damages the cell walls and thus the arteries. The body reacts to this with inflammation and increased release of LDL cholesterol. With the LDL cholesterol, the body tries to patch up the damage like on an old street. That means you have more LDL (also incorrectly called bad cholesterol) in the blood per HDL, which acts as a transport agent for the LDL. This creates a higher LDL to HDL ratio. The classic symptoms of all cardiovascular patients.
The second problem is that the body stops long-term construction projects. Metaphorically speaking: If a tornado is heading for your house, it is not time to paint your garage. Rather, You nail the windows shut and you do everything to keep your house safe. Even if that's not necessarily the best way to increase the value of your home in the long term, it is better because you still have a home after the tornado. Everything is only cleaned up and repaired as soon as the tornado is over. The new brick wall, which is to replace the broken wooden wall, takes time to finish.If there is a tornado every day, it will be very difficult to keep the house in good shape in the long run.
Transferred to our body means that it e.g. stops digestion (therefore chronic stress also leads to digestive problems). The repair and growth of tissue cells (e.g. bones and muscle fibers) is interrupted. We set the so-called anabolic, build-up state and go into a catabolic, breakdown state. That means we draw on our reserves in order to survive the emergency situation. Such an emergency is also not the time to reproduce. Reproduction mechanisms are therefore reduced or stopped altogether. Chronic stress in women can lead to an irregular cycle or even to the fact that menstruation is completely absent. This is actually the case with many top female athletes. The University of Michigan has more on this ...
“ Nine out of ten of the competitive female athletes I look after in the field of endurance sports do NOT get their periods in hard training phases. ”
- Oliver Zimmerli, AURUM Coach and Endurance Coach
In men, permanent stress causes sperm count to drop and testosterone levels to decrease. Our immune system is also inhibited by an acute stressor. The energy is better used to escape the lion instead of fighting off a cold or discovering and fighting a tumor cell. Good if there is a morning when I can have a cold.
“The immune system, which defends against infections and illness, is ideal for spotting the tumor cell that will kill you in a year, or making enough antibodies to protect you in a few weeks, but is it really needed this instant? The logic here appears to be the same – look for tumors some other time, expend the energy more wisely now”
— Robert M. Sapolsky, Neuroendokrinologist
The third problem is that chronic, repetitive stress can trigger a vicious cycle. In a stressful situation, stress hormones such as cortisol and glucocorticoids are released, which, among other things, keep the sympathetic nervous system activated. If our body suffers from chronic stress, the activity of the sympathetic nervous system makes it difficult for us to sleep. Poor sleep, in turn, prevents us from recovering well from stressors. The glucocorticoids already mentioned can also contribute to another tragic vicious cycle. The hypothalamus controls the gland (adrenal cortex) and thus the level of glucocorticoids in the blood. The glucocorticoids are among those hormones that suppress the immune system. According to recent studies, the main problem is that permanently high levels of glucocorticoids damage the hypothalamus itself and therefore regulation no longer works so well. And this means that the damaged hypothalamus signals the adrenal cortex to release glucocorticoids, which in turn are harmful to the hypothalamus itself. As a result, there is a risk that at some point we will no longer be able to stop the stress reaction and that our immune system will be permanently suppressed.
Now let's consider everything we've learned about the body's stress response. What are the conclusions for optimal training for humans?
So this should be the optimal week:
Low-intensity activities can therefore be included in terms of length and frequency at any time. These activities such as relaxed yoga, hiking, etc. have a long list of other positive health effects, but do not stimulate adaptation. So these should be built into your daily routine as often as possible. The middle zone is problematic. With medium intensity you get a lot of stress for the body with limited adaption. So a bad adaption / stress ratio. With high intensity training you get the most stress, but also the most adaption. So the best adaption / stress ratio. But only - and only then - when you really relax after a high intensity training and you give your body enough time to recover.
Life is just too short to spend in the gym. And as we now know, that's also wrong. Nevertheless you need training to enjoy life at the highest level. The optimal strategy lies in high intensity training. That is why AURUM has dedicated itself to the mission of providing all people with the power to enjoy life through high intensity training.
Hi, I am one of the co-founders & the CEO of AURUM. My passion for sports formed early during my sailing career. The seed of knowledge planted there grew into research and experimentation of different approaches in nutrition, exercise, mindfulness and all things related to a happy and purposeful life. I hope you enjoy my articles. Feel free to get in touch.
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