The modern time presents a lot of different stressors that we encounter in our everyday lives. Be it the noises in cities, air pollution, the omnipresent microplastics, or perhaps stress at work, at home, or on social media, in the long run, this kind of low intensity stress numbs our nervous system unless we balance it out with positive stress. The resulting numbness leads to a reduced ability to perceive our own body, and thus, paradoxically, our nervous system becomes numb and oversensitive at the same time.

Thanks to specialised fields of study, such as neuroscience and biology, we realise more and more that the human body is comprised of many different systems. And it is none other than the nervous system that controls all others. The lead organ of this system is a brilliant piece of white-grey matter, our brain. It controls everything. Our brain consists of very specialised cells called neurons. The nervous system as a whole gives us the ability to feel. We are able to see, hear, and react thanks to it. It gives us the possibility to choose whether we dive in an ice cold lake or draw back, whether we eat or fast, whether we shall be happy or unbearable, read a book or go to sleep. This system creates our emotions, thoughts, fantasies, ideas, and memories. If we think about it, it shows us the reality composed of various reactions, to which it then reacts. It is a sort of reflected image of ourselves.

We can say that our autonomic nervous system consists of two branches:

• Sympathetic nervous system: The sympathetic branch is responsible for the fight-or-flight response. If there is too much need for this response, it is harmful for our organism. That is when we have to engage the parasympathetic nervous system. If we immerse ourselves in an ice cold lake, for example, the sympathetic branch is activated, but as soon as our body begins to adapt to the cold and our breathing slows down, the parasympathetic branch is activated.
• Parasympathetic nervous system: This system helps us with the general maintenance of our organism, such as food digestion. Being able to activate the parasympathetic branch is very beneficial to us. In a stressful situation this can be done by taking a distance. We can slow down, calm down, and take a deep breath. In cold water we can also slow down our breathing and practise chanting - producing a long-drawn constant tone whose vibrations stimulate the vagus nerve and activate the parasympathetic branch.

The great news is that we can intentionally and positively influence our nervous system and thus improve the quality of our life. Our brilliant neurons can be trained to do almost anything, any skill we wish. This means that every one of us can transform completely. If you work on yourself and acquire new skills, you may notice that you have changed so much in the last ten or even just five years. It is quite probable that you now have more in common with the people around you than with yourself a few years ago.

Brain plasticity

What I find truly fascinating about the human brain is its adaptability. If you walk with cold for a long time and practise cold therapy regularly, you repeat the same pattern over and over again. It is the same when you are learning any other skill. This activity is like a code that is being stored in your memory. When you do yoga, martial arts, or any other sport, your brain is being shaped by regular and repeated practice. This phenomenon is called neuroplasticity, and I suppose you have heard of it before. My kendo sensei (master) always tells me that every little activity and the way I approach it has an effect on how I do everything else. So if I take the tram and need to grab the handle, I do it as if I were gripping a sword. When I am walking down the street, I walk erect, as is preparing for a duel. I am always alert and calm. 

All the little daily activities train your brain and nervous system in the direction you want. What you do over the course of a day, how you walk, how many times you get up to do some squats or splash yourself with cold water, how often you go out to get some air… This is why our health truly depends on us and no one else. We have the ability and possibility to train our nervous system ourselves, becoming more resilient to both external and internal factors.

Every neuron is capable of creating 10.000 connections with other neurons. This network changes according to our most frequent activities. When you learn a new move or step once in a cold shower, the neural pathway created is only temporary. It is made with chemical compounds surrounding the neuron. If you repeat the action, however, and practice the cold shower or another activity day in day out, the chemical compounds turn into a structure. With time, as you keep practising on a regular basis, the connections between different parts of your brain grow stronger. This brilliant mechanism changes the structure of your brain, your nervous system and with it, the way you perceive reality and react to it. You change.

For example, if you practise ice baths regularly, there will come a time when your nervous system will be so resilient that it will allow your body and mind to become one. You will literally fuse into a single organism. This sense of unity can occur in different situations, and let me tell you, if you experience it in a cold lake, you will never forget it. Cold therapy is not only about physical and mental benefits, for many it has a spiritual dimension as well.

CAREFUL!

Once again I repeat: If you want to stay with cold for a long time and discover the treasures hidden inside you, you must proceed with kindness, gentleness, and humility. If you force anything, your nervous system may break down. You will create more stress for your body than if you did not practise cold exposure at all. Keeping this in mind, do not be afraid to make mistakes. If you happen to overdo it, do not beat yourself up. Take a moment to reflect upon it and then keep going. You will do better next time.

If you want to be long-time friends with the cold, I suggest you track yourself. At Systers, we have prepared a cold protocol for you, which can be obtained here. All you have to do is print it out, start practising, and write everything down. You will see how helpful those notes will be in the future.

I wish you a fun journey in cold, may it bring you more peace, balance, and energy in our life.

Cold exposure presents certain health risks, especially when performed without the supervision of another person. Even if you are advanced, always practice cold therapy with at least one other person who will look out for you, especially outdoors. Always treat your body kindly and approach it consciously. Men usually find this principle very challenging, but I have noticed that women are often able to understand the fine line. It is simply thin ice. Each one of us should learn to recognise when we are just stepping out of our comfort zone, and when we are forcing ourselves and should stop. This is precisely why we need to train and experiment. We must not be afraid to make mistakes in order to find our own limits, which we will respect.

If you practise breathing techniques before cold exposure (which in itself would be enough material for an entire book), such as diaphragmatic (belly) breathing or the Wim Hof method, you also need to know what to watch out for and what doses are safe. I recommend watching the video in the link below that I once made together with Libor Mattuš.

Animated video (in Czech): The potential risks of cold therapy and the Wim Hof breathing technique.

So what are the main risks on the path of cold therapy, and what do we need to watch out for?

Hypothermia and drowning

The most common risk associated with cold exposure is hypothermia, when your body temperature drops under 35 °C. (1) This can happen when you misjudge the dose and simply overdo it. The symptoms include shivering, which can last for hours, hyperventilation, paleness, fatigue and drowsiness, but the signs may vary in each of us. We should also remember that as we change within our cycle - not just our hormonal cycle, but also the life cycle - our ability to adapt to cold also changes. This causes a shift in the limit of when we need to take it easy and when, on the contrary, we can dig deeper.

I would like to share a personal experience with this health risk. It happened during my first submersion in a cold lake, without any previous training and without listening to my body. Hypothermia occurred, my body temperature dropped under 35 °C and I began to lose consciousness in the water. If my mum and my boyfriend at that time had not been on the shore, I would have drowned. They pulled me out and took me home. I was shivering for hours, and felt cold in my bones - I was wearing several layers of clothing but simply could not get warm. My lips were purple. Then fatigue hit until I finally fell asleep. This is not a wholesome state. All the same, I am grateful for this experience because my body showed me once again where my limits lie.

If you are pregnant, it is important to practise cold exposure either locally or truly gently. Ice baths are not recommended because your baby might get chilled and so might you. This is a really fine line, and it is better to experiment with water of about 10-15 °C, but do it regularly, even twice a day. You can splash your body with cold water, take a cold shower for less than a minute, or go out in the snow barefoot, just for a minute. That is enough.

The shivering you experience after cold exposure occurs naturally, it is called afterdrop. When we come out of cold water, the cooler blood returns from the extremities into the central circulatory system causing a drop in the body temperature and shivering. Shivering is produced by small involuntary muscular contractions which the body uses to generate heat.

Frostbite

Frostbite is another health hazard which occurs when the skin freezes. This usually happens on the extremities or the face. Alcohol consumption can increase this as well as other risks. Although you can see people in Russia, for example, drinking alcohol as if it were water, while immersing themselves in cold lakes, this practice is neither safe nor beneficial for the human organism. During my winter expeditions to Sněžka, I have also seen a few men appear with a flask of liquor, saying that it would help to keep them warm. The truth is that in spite of the warm feeling produced by drinking, alcohol causes a lowering of body temperature and increases the risk of hypothermia and frostbite during cold exposure. (2)

A dramatic drop in blood pressure

If you combine extreme heat and extreme cold, be it with water or in the sauna, your blood pressure can change drastically and suddenly, and you may lose consciousness. (3)

Heart attack

Another big “killer” is heart attack which can happen when the temperature of the blood that returns to the heart suddenly drops - this can affect the electrical impulses in the heart and cause fibrillation. In general, if you have any health problems, you should proceed slowly when working with cold. Take it step by step. You do not have to dive in ice cold lakes right away, putting your health or even your life at risk.

Every one of us will have a different optimum level of cold exposure. Some of you may happily practise cold therapy every single day, even during menstruation, while others may find that once a week is enough for them. It is very important to create a protocol, approach it as an experiment, collect data and observations for a while, and subsequently use these as a basis to decide in what doses you should administer cold to yourself. You can request one such protocol that we have prepared for you here. All other risks have to do precisely with dosing. You do not want to overdo it. Biohacking is a path of harmony and balance.

Bibliography:

1. https://link.springer.com/article/10.1007/s12024-010-9142-4
2. https://www.sciencedirect.com/science/article/pii/S0953985994710998?via%3Dihub
3. https://pubmed.ncbi.nlm.nih.gov/3218896/

When learning to cook, we do not just learn the recipes, we need to learn the principles of cooking. The same applies to cold therapy. As soon as we understand the principles and set solid foundations, we can build a pyramid. And a pyramid can remain standing for a very long time.

1st Principle: Mindset

Whenever we are learning something new, having the right mindset is key. Without it, nothing we do can have a long-lasting and sustainable effect, simply because our mind will not accompany us. The mind is powerful, and it can distract us very easily from what matters to us.

Knowing why I want to start with cold therapy, what it means to me, is crucial. Ideally, we are looking at an inner motivation which comes from ourselves, not from the outside. In those moments when we do not feel like getting into the cold shower, we can always remind ourselves of the original intention. Cultivating a growth mindset helps. Then if one day you skip the cold shower or do not stay for as long as you wanted, you do not assume the role of a victim, but you will know it is alright, you will try again next time. When I started practising cold therapy, my mindset was the essential factor that helped me walk hand in hand with cold in a sustainable way. You can call it intention, motivation, whatever feels right and natural to you. In any case, identify your why and - better still - write it down somewhere on a piece of paper or in your diary.

TIP:

I highly recommend starting a diary if you do not have one yet. In it, you will write your protocols and observations during the entire process of cold therapy, along with your intention: why you want to start practising in the first place, what you want to learn from the cold. I do not recommend skipping this point. You will see that in a few weeks or months you will have collected valuable data regarding your feelings, the lessons cold has taught you and so on. You will appreciate the data in time. If you want a ready-to-use cold therapy protocol, at Systers we have prepared one for you. My husband Johnny put it all in a table and our lovely Klárka took care of the graphic design. You can print it out, put it on your fridge, and start practising.

You can download the protocol here.

2nd Principle: Courage and Inner Strength

Working with cold has a lot to do with courage. It is about taking the first step. Whenever I am in the shower, I do not want to turn the tap to the other side. When I go out wearing nothing but a T-shirt in the cold, I do not feel like it at first, even though I know deep down that I am somehow looking forward to it. Even after all these years, the feeling does not go away. It is still there, but I perceive it differently, just like the cold. It is better not to think when working with cold, just jump right in. You can try using the Samurai rule of three seconds - when you want to do something, do it within three seconds, otherwise your mind will try to talk you out of it. This rule reminds me of the transience of things and my courage. Courage is closely linked to inner strength.

Every time you step out of your comfort zone, your inner strength grows, as if it was awakening to the maximum of its potential. It is a wonderful feeling which will help you in other areas of your life as well. At the shooting range, my master, who trains me in shooting and various martial arts, always tells me: “Work with stress, total relaxation, resilience, and complete focus, all of this you know from your ice baths. Now all you have to do is transform this skill and bring it to another area, to shooting. Focus, relax, and above all, don’t think. Shoot!” He is right. Although it is not always easy to transform this skill into another, it can be done. Your courage and inner strength, which grow with every dose of cold, will support you in other life situations.

3rd Principle: Self-love and Gentleness

Careful, though, we need to find the fragile balance between courage and inner strength on the one hand and self-love and gentleness on the other. At the beginning of my journey with the cold, when I used to compete with others to see who could stay longer in the cold water, I would often overdo it, and instead of the positive eustress, I would produce negative stress in my body. Suddenly I felt more fatigued and started to fall sick again. I did not understand at first, but then I realised that I had disrupted the harmony and equilibrium, and started harming my body. My nervous system was overloaded and I began to fall back into a dark hole.

Work with cold is a never-ending game of getting to know yourself. It is great fun, and you will see that in time you will reach certain breaking points where you will feel such bliss that you will never want to stop. No matter your level of experience with cold exposure, believe me when I tell you that you can get so far beyond anything you believe possible. Beyond anything you can imagine cold can offer you. Once you truly relax in the process, you can experience truly amazing states of expanded consciousness. The trick is to remain aware, centred, and stay with the cold sustainably for a long time. Accept the cold and relax into the discomfort.

4th Principle: Mindfulness

Mindfulness is extremely important in cold therapy. It is about being present in your body in the moment, not letting yourself get carried away by your thoughts or feelings. While you are immersed in the ice cold bath or taking an ice cold shower, you can use different mantras, such as, “I am here,” “I accept you,” “I love you,” etc. Unfortunately, many people become tense and fight the discomfort. That is not a good strategy. Women tend to have less difficulty and usually manage to relax. The tenser we are, the more energy our body and muscles burn. If we relax, the experience is more enjoyable, even ecstatic, after some time. I have had such an experience a few times, and I must say it is really something. The moment we accept the cold, not reject it, we can relax and go through the process with much more ease. 

Another thing I have noticed is that women tend to approach water and the whole process with more respect. Cold therapy can and should be a kind of ceremony. At my camps, when I lay women in the ice bath, we typically look deeply into each other’s eyes, I hold her hand, and she immerses herself in the water, gently and gradually. We breathe together, without talking. The woman is within herself, does not let her surroundings distract her. Then she closes her eyes and allows herself to float in the present moment, with the cold. It is a transformational experience, not only for the woman but for me. Every single time. It is such a wonder and such an honour!

I would like to thank all the women who allowed me to share this profound experience with them.

5th Principle: Slowness

In my first book, Burn Slowly, I write in great detail about the importance of slowness in today’s hurried world, and we cannot overstate it when it comes to cold therapy. If we hurry and race, then - paradoxically - our speed can slow us down and stop our progress completely. This is not an advantageous strategy, believe me. I have been there. You can come out at a much lower point than where you started. On the other hand, what do I know about your journey. :)

In cold therapy, sustainability is crucial. We want cold to be our friend for life, not just a fling. That is why it should be administered continually in smaller doses, rather than once with high intensity. There is no rush. We can start by practising cold exposure only on our hands and feet and, when we are ready, we increase the dose. Everything is all right. Each one of us will have a uniquely intimate relationship with cold.

6th Principle: Regularity by Cyclicity

We are women. Or, to be gender-neutral, we are people with a vagina. If you feel like a man but are equipped with a vagina, this text is also for you. The biggest myth in personal development and biohacking is that we should all repeat one habit every day for a prolonged period of time. This can work for men, but not women. Even though we can feel it is beneficial in the beginning, after some time we realise that this approach harms us in the long run. It is important to synchronise cold therapy with our cycle. I describe this in more detail in my e-book on cold therapy which will be available for you in February 2022 (in Czech). On the other hand, regularity is also important. You might want to plan your cold therapy in cycles that suit you. The thing is that if you do not establish any system at all, you might easily quit cold therapy before you even get started.

So much for the basic principles. I wish you all an enjoyable journey with the cold.