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Dr. Susanna Søberg and Cold and Heat Therapy

Stressed, burnt out, or lethargic? Unfortunately, the stressors of modern life and simply trying to keep up with the day-to-day can lead to health issues, low energy, and burnout. Many people have been turning to alternative therapies and holistic ways to increase metabolism, ground the mind and body, and ease tension.

With so many different holistic therapies and practitioners on the scene, one scientist has paved the way in understanding rest, stress, and metabolism. Dr. Susanna Søberg has explored cold and heat therapy as means to optimize the mind and body. At RENU Therapy, we are huge advocates of her work and support her studies and principles relating to cold and heat therapy.

Who is Dr. Susanna Søberg?

A Ph.D. holder from The University of Copenhagen, Dr Susanna Søberg has dedicated herself to understanding human metabolism during stressful and restful periods. She has expertise in functional breathing and cold and heat therapy and has refined these practices to help people around the world. Dr. Søberg is interested in using these modalities to optimize performance and reduce stress and burnout and has created numerous health programs that are meant to heal and empower.

 Dr. Susanna Søberg cold plunging in icy cold water

Image courtesy of Google Images

Dr. Susanna Søberg’s programs are meant to:

  • Lower stress
  • Improve sleep
  • Increase physical and mental health
  • Decrease burnout
  • Help you to achieve a high level of performance

Winter Swimming 

Dr. Søberg is known for her first book, 'Winter Swimming', a deep dive into the cold-shock response, the science of cold water exposure, and the Scandinavian practice of winter swimming. She explores the effect that the icy water has on the body and the challenges and how-tos of starting cold plunging or cold-water swimming.

In the book, Dr. Søberg discusses the effects that cold water swimming and plunging have on the body's mental and physical health. She researches people in Nordic countries, who have practiced outdoor swimming in frigid waters during the winter season and warmed up in saunas for centuries. From circulation and metabolism to the immune system and mind, she examines the effects that the endorphin rush that cold temperatures have on the body and how the activation of brown fat benefits the body.

'Winter Swimming' recognizes that a cold plunge practice is not easy, but Dr. Søberg breaks down the challenges and ways to overcome them and makes it a regular practice. Moving through the mental and physical difficulties of cold plunging can inspire you to break through other challenges you may be facing and live a healthier and happier life. From increased confidence to the improvement of health conditions, she illustrates that we can learn a thing or two from Scandinavian winter swimmers.

Metabolism and Cold and Heat Exposure

Dr. Søberg has studied metabolism and the human response in different environments. She has specifically studied brown fat, also known as brown adipose tissue, which helps to maintain your body temperature when you get too cold. Her studies have noted the effect of cold and heat exposure and how this specific practice positively affects the body and mind.

What is The Søberg Principle?

Named by Professor Andrew Huberman from Stanford University, the Søberg Principle is all about alternating between hot and cold therapy through cold plunging and saunas, ending with cold exposure. When you end up in a cold plunge and in cold temperatures, your body needs to expel energy and shiver in order to heat back up. This contrast therapy ending with cold, forces your body to warm up on its own. This, in turn, increases your metabolism and activates and stimulates your brown fat to generate heat.

Hot and Cold Therapy

Contrast therapy has a significant positive impact on your health. Dr. Søberg preaches the importance of ending with cold exposure at the end of your practice. She also explains that this practice is all about micro-stressing the body and that moving from one extreme temperature to the other, it creates healthy stress that can strengthen your mind and body.

RENU Therapy Zeno 2-Person Barrel Sauna and Cold Stoic 2.0 Cold Tank for practicing Dr. Susanna Soberg's Soberg Principal in backyard


While alternating from sweltering to freezing temperatures can be daunting, you can work your way up to lower temperatures and a longer practice with time. In addition, finding that 'sweet spot' is important. Be mindful to find a balance in the practice that doesn't make you too stressed as this can cause inflammation, overwhelm, and tension.

Sauna and Cold Plunge Routine

So what is the perfect hot and cold therapy routine? Dr. Søberg suggests 11 minutes of cold per week and 1 hour of heat each week. This can be spread over the week over 2-3 sessions. Each session should alternate between a cold plunge and sauna (about 2-3 times), and it is important to end with cold.

After your final cold dip in each session, allow your body to shiver and warm itself up. In order to allow your body to heat up naturally, try not to cross your arms or towel off. This increases the metabolic effect and will allow you to reap more benefits of cold therapy paired with heat therapy. While it may be challenging at first, resist the urge to warm yourself up with a towel or end with a hot shower or session. The more that you practice, the easier it will become!

What Temperatures Should I Be Aiming For?

While your icy plunge pools should be cold, it should always be safe. Temperatures that are colder than 19 C or 66.2 F can activate brown fat and create what Dr. Soberg refers to as the 'inner fire'. If it is your first time, be prepared to feel a cold shock and work on taking deep breaths while in your ice bath. When you switch to your sauna, make sure that you use a traditional sauna that can reach temperatures of 85 C or 185F.

Outdoor RENU Therapy cold plunge tank and sauna with temperatures

Stay in your cold plunge and sauna for a few minutes at first, and work your way up to a longer period of time. Remember that the ideal practice for hot and cold therapy is 11 minutes of cold and 1 hour of heat each week. If you are not quite sure when to switch, Dr. Søberg suggests moving at your own pace and staying until you are uncomfortable but still able to feel safe enough to build up resistance.

Practicing The Søberg Principle with RENU Therapy  

If you are curious about the health benefits of The Søberg Principal, cold plunges, and heat therapy, RENU Therapy has the answer! As leaders in the cold water immersion therapy space, we offer 4 different models of our popular and aesthetically pleasing cold plunge tanks. These tanks can be used in your gym, wellness center, or even your home.

Woman cold plunging in RENU Therapy Cold Stoic 2.0 cold plunge tank

In addition, we have both outdoor and indoor saunas to compliment your cold plunges. Switch from an icy cold plunge to a toasty sauna made by RENU Therapy with high-quality lumber. With so many mental and physical benefits, it’s no wonder more people are jumping on this latest wellness trend and trying the Nordic way to health and vitality.

To improve your quality of life and learn more about contrast therapy, cold plunging, and saunas, contact our team today!