Dr. Susanna Søberg is an expert in deliberate cold and heat exposure, focusing on the minimum thresholds for increasing heat production and metabolism. Her research explores the effects of cold and heat on neurotransmitter production, mood, and metabolism. She provides actionable protocols for improving metabolism and overall health. Dr. Søberg discusses the nuances of cold and heat exposure protocols, including the difference between cold showers and immersion. Her expertise has led her to publish a book titled "Winter Swimming." Deliberate cold exposure has long-term health benefits, including increased levels of catecholamines, improved activation of brown fat, and increased comfort in cold environments. Cold showers and immersion in cold water both activate brown fat and increase metabolism. Cold exposure can also reduce inflammation and improve insulin sensitivity. The "Soberg Principle" suggests that ending on cold exposure can improve health and metabolism. Cold exposure can benefit individuals with Raynaud's Syndrome and autoimmune conditions. Children have a higher risk of hypothermia and caution should be taken when exposing them to cold temperatures. There may be gender differences in temperature perception and metabolism, but both men and women can benefit from cold exposure. Brief, repeated temperature changes can improve health by challenging the body's cells to adapt to changing temperatures.
Dr. Susanna Søberg
Dr. Susanna Søberg, a leading expert in deliberate cold and heat exposure, focuses on discovering the minimum thresholds for increasing heat production and metabolism. Her research also explores the effects of cold and heat on neurotransmitter production, impacting mood and metabolism. Dr. Søberg's work provides actionable protocols for improving metabolism and overall health. She discusses nuances in cold and heat exposure protocols, including the difference between cold showers and immersion, and their impact on the skin and brain receptors. Her expertise has led her to publish a book titled "Winter Swimming." In her discussions, Dr. Søberg covers cold acclimation, the cold shock response, and the impact of heat and cold on human health. She also explores the differences between sauna, ice, and cold swimming showers, aiming to give viewers the confidence to safely embrace these protocols and achieve their desired health outcomes.
The Brain-Body Contract
The Brain-Body Contract explores tools and science related to mental health, physical health, and performance. Dr. Susanna Søberg discusses the use of cold and heat exposure to improve health. Two live events will be held in September 2023 in Toronto and Chicago, featuring a lecture and a question and answer period.
Physiology in Uncomfortably Cold Environments
The physiology of uncomfortably cold environments involves the activation of the sympathetic nervous system and the release of catecholamines in the body. Key points include:
- Cold exposure triggers the sympathetic nervous system and the release of catecholamines.
- The temperature difference between the skin and cold water creates a shock.
- If the core temperature is warmer, the cold exposure feels less stressful.
- The sympathetic nervous system is responsible for heart rate acceleration, alertness, and the stress response.
- Catecholamines released during cold exposure include dopamine, epinephrine, and norepinephrine.
Tool: Water Temperature, “Cold Shock” & Discomfort
The most profound aspect of the topic is the use of cold and heat exposure to improve health.
Key points:
- The temperature of the water for deliberate cold exposure depends on the difference between the body's current temperature and the water's temperature.
- Getting into cold water feels good when the body is warm, but feels stressful when the body is already cold.
- Experiencing "cold shock" by getting uncomfortably cold activates the sympathetic nervous system.
- Controlling breathing can be a gauge of the cold shock response, typically leading to hyperventilation.
- With adaptation and training, the hyperventilation response can subside.
- Building resilience and adaptation through exposure to cold water is important.
- Cold water immersion can be uncomfortable and challenging to regulate.
- Some individuals struggle with cold water exposure and may experience anxiety or agitation.
- Others embrace the discomfort of the cold and feel better in cold temperatures.
- The response to cold exposure varies greatly among individuals.
- Some individuals, like soldiers, may already be adapted to the cold and not scared of it.
- Individuals with a more sensitive nervous system may try to avoid the cold and experience more pain when exposed to it.
Cold Showers vs. Immersion in Water, Brown Fat
Cold showers and immersion in cold water have different impacts on the body, but both can activate brown fat and increase metabolism. Immersion in cold water activates the cold receptors in the skin more rapidly and strongly, leading to the activation of the sympathetic nervous system and an increase in norepinephrine. Cold showers, although less studied, also activate brown fat and may impact neurotransmitters in the brain. However, there are fewer studies on cold showers compared to cold immersion, likely due to methodological challenges. More research is needed to fully understand the effects of cold showers on health.
Cold Receptors, Brown Fat & Temperature Homeostasis
Cold Receptors, Brown Fat & Temperature Homeostasis:
- Cold receptors on the skin send a signal to the hypothalamus, triggering the activation of brown fat.
- Adrenaline and cortisol are released in response to the signal, further activating brown fat.
- There is a direct pathway from cold receptors to brown fat, suggesting its role in maintaining temperature homeostasis.
- Muscles also have a pathway to brown fat, indicating their collaboration in regulating body temperature.
- Cold exposure activates multiple survival mechanisms, including brown fat activation and muscle shivering.
- Brown fat plays a significant role in temperature homeostasis and warrants further exploration.
Shiver, “After Drop”, Healthy Stress
Shivering is an important and beneficial response that increases metabolism and burns calories. After being in cold water, the "after drop" phenomenon occurs, causing the core temperature to continue to decrease. Shivering is induced by this drop in temperature and activates brown fat to warm up the body. Shivering should not be avoided, as it is a form of training for the body that increases insulin sensitivity and strengthens muscle and brown fat cells. Exposing cells to healthy stresses like cold water immersion leads to adaptations that lower blood pressure and inflammation.
Long-Term Health Benefits of Deliberate Cold Exposure
Deliberate cold exposure has long-term health benefits, including increased levels of catecholamines, dopamine, norepinephrine, and epinephrine, improved activation and efficiency of brown fat, increased comfort in cold environments, and improved fitness adaptations. It also improves the body's ability to constrict blood vessels, reduces the stress response, and increases insulin sensitivity. Studies have shown that deliberate cold exposure can lower blood pressure, heart rate, and improve insulin sensitivity, suggesting it may help prevent lifestyle diseases and reduce inflammation.
Blood Pressure & Heath
- Blood pressure is a crucial aspect of health and a leading cause of death worldwide.
- Cerebral vascular disease and cardiovascular disease are the main culprits.
- Controlling blood pressure is essential for longevity and health span.
- Deliberate cold exposure, combined with exercise, is an effective method for regulating blood pressure.
Brown Fat, Insulin Sensitivity & Metabolism
Brown fat, a type of fat rich in mitochondria, can expand and decrease in distribution and grows in response to adrenaline without causing weight gain. It is an insulin sensitive organ that can be activated through cold exposure. After the age of 40, people tend to have less brown fat and increased obesity, possibly due to a decrease in brown fat as a result of obesity. Insulin sensitivity is important for overall health, and individuals with more brown fat, such as farmers who work outside, tend to have better insulin sensitivity. Physical labor or manual work throughout life contributes to better health and fitness, even in old age.
Temperature Regulation, Brown Fat vs. White Fat
The most profound aspect of the topic is that brown fat can be activated by exposure to cold temperatures, even without extreme cold or deliberate cold exposure.
Key points:
- Just a little bit of exposure to cold, such as putting your hand in cold water or going outside in a t-shirt, can activate brown fat.
- People who work outside or experience frequent temperature changes have more brown fat.
- Activating brown fat can increase metabolism and insulin sensitivity.
- Wearing cooling vests or sleeping in a cold environment can also activate brown fat.
- Brown fat, unlike white fat, is beneficial for health as it helps with insulin sensitivity and thermogenesis.
- By increasing brown fat activation, unhealthy white fat can be reduced, leading to improved overall health.
- Brown fat is located centrally around the central nervous system, with the largest depot being under the clavicular bones.
- The activation of brown fat leads to an increase in temperature, and it is located close to the skin surface.
Cold Resilience, Scandinavia
Cold resilience in Scandinavia is achieved through various practices, such as exposing babies to cold temperatures and engaging in outdoor activities. These practices have been found to improve thermal regulation, boost the immune system, and promote overall fitness and health. Key points include:
- Wearing a t-shirt in a cold room led to cold adaptation, expanding brown fat and increasing comfort in the cold.
- Exposing babies to cold temperatures in Scandinavia dates back to the 1950s and helps activate brown fat, improving their ability to regulate body temperature and making them more resistant to the cold.
- Scandinavians have a culture of cold resilience and outdoor activities, including swimming in cold water, which contributes to their high levels of physical activity and overall health.
- This approach to cold resilience differs from the comfort-focused mindset in the United States and may have significant health benefits.
Winter Swimmers & Brown Fat; Discomfort
Winter swimmers and those who engage in cold exposure can improve their health by activating brown fat. Despite initial discomfort and anxiety, individuals often feel fantastic, invigorated, and energized after cold water exposure. The goal is to find the lowest effective dose for health benefits and avoid excessive cold exposure. The key is to find the right balance of hermetic stress, which promotes health benefits.
Sex differences & Brown Fat, Cold-Adapted
The most profound aspect of the topic is the sex differences in brown fat and cold adaptation.
Key points:
- Women have more brown fat than men, which may be related to their smaller size and lower peripheral temperature.
- Women have a lower thermal comfort level compared to men, with men being thermocomfortable at 22 degrees Celsius and women at 24 degrees Celsius.
- The speaker conducted a study on winter swimmers who were already adapted to the cold and compared them to a control group.
- The study found that women have more brown fat than men, leading to their choice of studying one gender in their proof of concept study.
- Winter swimmers who had been swimming for two to three seasons and stayed in the water for one to two minutes, two to three times per week were recruited for the study.
Diving Reflex & Parasympathetic Activation
The diving reflex is a survival response that slows down oxygen consumption and reduces heart rate when the body is submerged in cold water, leading to relaxation. It can be activated by submerging the entire body or just the face. This response is part of the parasympathetic nervous system, responsible for the "rest and digest" response. Cold and heat exposure can activate the diving reflex and parasympathetic activation, releasing serotonin in the brain and promoting mental balance and well-being. Further research is needed to understand this phenomenon better.
Tool: Deliberate Cold & Sauna Protocol
The deliberate cold and sauna protocol for improving health involves participants climbing down a ladder into cold water for 1-2 minutes, then entering a sauna at 80 degrees Celsius for 10-15 minutes. This process is repeated three times, ending with a final dip in the cold water. The study aims to mimic a natural environment and its positive impact on stress levels. Key points include:
- Participants are encouraged to find the right timing for cold exposure that works for them, as it can impact sleep.
- The activation of the sympathetic nervous system through cold exposure, exercise, or coffee can make it difficult for some people to fall asleep.
- Experimentation is key to finding the best approach for each individual.
Winter Swimmers, Shiver; Circadian Rhythm & Brown Fat
Winter Swimmers, Shiver; Circadian Rhythm & Brown Fat
- Winter swimmers who are adapted to cold water exposure experience less vigorous shivering due to denser and more efficient mitochondria in muscle cells.
- Winter swimmers show increased insulin sensitivity and produce less insulin, indicating potential metabolic benefits.
- Winter swimmers have lower production of insulin and faster glucose clearance in the bloodstream, which is beneficial for overall health.
- High blood glucose levels are toxic to brain cells, and insulin helps regulate blood glucose levels.
- Extreme temperatures can be detrimental to brain cells, potentially permanently destroying them.
Tool: Minimum Threshold for Cold & Heat; Sauna & Cardiovascular Health
Dr. Susanna Søberg's study found that 11 minutes of total exposure per week, divided into 1-2 minutes of cold water exposure and 10-15 minutes of sauna exposure, resulted in positive changes such as reduced blood sugar, improved insulin sensitivity, and increased brown fat density. This aligns with previous studies that suggest up to 30 minutes in the sauna per session is beneficial for cardiovascular health. Beyond this threshold, there are no additional health benefits. The concept of "healthy stress" or hermetic stress is important, as it stimulates the production of heat shock proteins that repair cells.
- 11 minutes of total exposure per week is sufficient for positive health changes
- Cold water exposure for 1-2 minutes and sauna exposure for 10-15 minutes are recommended
- Reduced blood sugar, improved insulin sensitivity, and increased brown fat density are observed benefits
- Up to 30 minutes in the sauna per session is beneficial for cardiovascular health
- "Healthy stress" or hermetic stress stimulates the production of heat shock proteins that repair cells.
Tool: Maintaining Stimulus when Cold-Adapted; Shorter Sessions
The most profound aspect of the topic is the importance of maintaining stimulus when cold-adapted through shorter sessions of cold exposure.
Key points:
- The threshold for deliberate cold exposure is 11 minutes per week, divided into two or three sessions of one to three minutes each.
- Dividing 57 minutes into three 20-minute sessions is suggested to avoid rounding up to an hour.
- Shorter bouts of cold exposure are important for the hermetic response and to avoid becoming too cold adapted.
- The goal is to keep the stimulus short and not aim for longer durations of cold exposure.
- Shorter sessions are more practical and beneficial for maintaining stimulus when cold-adapted.
Cold Exposure, Sleep Quality, Clothing
Cold exposure, sleep quality, and clothing are the main topics discussed in the given summaries. Here is a combined summary of these topics:
Exposing oneself to cold temperatures, such as through winter swimming, has been found to improve sleep quality and reduce social anxiety. While sleep quality was not directly measured in a study on winter swimmers, anecdotal evidence supports their claims of sleeping well. Winter swimmers also reported feeling comfortable in the cold and less self-conscious about showing their skin. However, it is important to note that getting too comfortable with the cold is not recommended, and naked winter swimming is not legal in most places in the United States. In Denmark, winter swimming and sauna are common activities for both men and women, although newer clubs now require bathing suits for privacy reasons. Saunas and cold plunges at home, as well as clothing-optional Russian Banyas in San Francisco and New York, are becoming more popular as people recognize the benefits of deliberate cold exposure and sauna use. It is worth mentioning that while there is no requirement to do cold exposure or sauna without clothing, it is a common practice in studies. These practices are not fringe or unconventional, as there is a growing body of research supporting their benefits. Wearing clothing during cold exposure is encouraged for acceptance and comfort.
“Brown Fat Negative” & Shiver
The most profound aspect of the text is the observation of a person who lacked brown fat and experienced difficulties in regulating their temperature and feeling comfortable in the cold.
Key points:
- A participant in a study on brown fat and shivering was found to be "brown fat negative" and unable to control his shivering during a cooling experiment.
- The person had higher insulin levels and slower blood glucose clearance compared to other winter swimmers.
- Despite being an outlier, their exclusion did not affect the overall results of the study.
- The implication is that individuals who shiver early may have less brown fat or have not adapted to the cold, suggesting the need to build up brown fat.
Cold & Heat, Inflammation Reduction
Deliberate cold and heat exposure have additional benefits for immune system function and overall health. They can reduce inflammation, which is linked to various diseases. By exposing ourselves to temperature changes, we can help our bodies repair and reset to a more balanced state. Our sedentary lifestyle and lack of temperature variations have made us more susceptible to obesity and other lifestyle diseases.
Key points:
- Cold and heat exposure can reduce inflammation.
- Inflammation is linked to diseases like type 2 diabetes, depression, anxiety, and Alzheimer's disease.
- Exposing ourselves to temperature changes helps our bodies repair and reset.
- Sedentary lifestyle and lack of temperature variations make us more susceptible to obesity and lifestyle diseases.
- Cold and heat exposure, along with exercise and fasting, increase hermetic stress and improve health.
Tool: “Soberg Principle”: End on Cold, Metabolism
The "Soberg Principle" suggests that ending on cold exposure can improve health and metabolism. Key points include:
- Ending on cold forces the body to heat itself back up, activating brown fat and muscles.
- This increases metabolism and thermogenesis, leading to a lasting effect even after the cold exposure.
- Individuals may feel warmer and maintain their body temperature more easily over time.
- Winter swimmers who ended on cold had higher skin temperatures and greater activation of brown fat.
- This may be due to the contrast between cold and warmth, resulting in higher heat loss and more vascular skin.
Overall, the goal is to maintain a well-tuned heating and cooling system by keeping brown fat functioning efficiently.
Cold Exposure: Fed or Fasted?
- Deliberate cold exposure and sauna can have benefits whether you are fed or fasted.
- The speaker personally does their cold exposure in the morning while fasting.
- More scientific studies are needed on fasting and fat during cold exposure.
Raynaud’s Syndrome; Hand/Feet Protection in Cold
Raynaud's Syndrome, a condition characterized by poor blood flow to the extremities, causes very cold hands and feet. Deliberate cold exposure may help alleviate symptoms by increasing capillary elasticity and plasticity, although specific studies are lacking. It is also suggested that deliberate cold exposure may benefit individuals with autoimmune conditions and other diseases, but research is limited. To protect hands and feet in cold weather, it is recommended to wear warm clothing, use hand warmers, and avoid smoking and caffeine. Gradual and cautious cold exposure can improve vascular health, while heat exposure can improve blood flow and reduce symptoms.
Tool: Headache & Cold Exposure; Head Submersion & Head Coverings
Cold immersion, specifically submerging the head in cold water, can cause headaches due to vasoconstriction and decreased blood flow to the brain. To prevent this, some people fully submerge their head or wear a cap while immersing in cold water. Studies show that submerging in cold water up to the neck at zero degrees Celsius can decrease blood flow to the brain by 30 to 40 percent. Wearing a beanie during cold exposure can help prevent dizziness and brain freeze. In Scandinavia, wearing head coverings in cold environments is common and can help individuals endure extreme conditions. Wearing wool caps in saunas insulates the brain and allows individuals to stay in the sauna longer.
Children & Hypothermia Risk
Children & Hypothermia Risk:
- Children have a higher risk of hypothermia due to their smaller size and higher surface-to-mass ratio.
- Children can defend their core temperature for up to one minute in cold water, but they use more energy and muscle activity compared to adults.
- Caution should be taken when exposing children to cold temperatures, as they can become hypothermic more quickly.
- Hypothermia can have serious consequences and should not be taken lightly.
- Approach cold exposure with caution, starting with cold showers and gradually progressing to cold immersion in still water.
- Open bodies of water pose additional risks such as currents and drowning.
Gender Differences & Cold Exposure
Gender Differences & Cold Exposure:
- There may be differences between men and women in terms of temperature perception and metabolism.
- Women can still benefit from cold exposure and activate their brown fat, which is important for thermogenesis.
- The duration of cold exposure may vary between men and women, especially in activities like ice swimming and avoiding hypothermia.
- Both men and women can benefit from short durations of cold exposure for hermetic stress and adaptation.
- Individuals who dislike the cold are ideal candidates for deliberate cold exposure, as the stress response and adaptation will be greater.
- Shorter and more frequent exposures are more effective than longer durations.
Tool: Brief, Repeated Temperature Changes; Circadian Rhythm & Temperature
Using brief, repeated temperature changes can improve health by challenging the body's cells to adapt to changing temperatures and strengthening them. This can be achieved through activities like getting in and out of cold water or a cold plunge for short periods of time. Variations in temperature throughout the day or in different seasons can also provide the same benefits. The exposure to cold is seen as a small stressor that the body adapts to, similar to a hermetic stress. It is important to consider circadian time in these temperature changes. The exact temperature or duration of exposure is not as important as the act of changing the temperature. Constant exposure to extreme cold or using ice is not necessary. Ongoing studies are being conducted to explore the effects of cold and heat exposure on both men and women, as there have been limited high-resolution studies on deliberate temperature changes and their impact on health. Dr. Susanna Søberg's work and public education efforts in this field are highly regarded.