Alternating between hot and cold temperatures (ex. from sauna to ice bath), aka contrast therapy, is greatly enhancing health and wellbeing globally. Wellness communities and self-development enthusiasts are adopting contrast therapy for its incredible benefits on human anatomy, physiology and psychological well-being. This method of therapy stimulates the body’s natural healing processes, improving circulation, reducing inflammation, and boosting overall well-being.
“We scientifically established that 11 minutes of cold-water immersion and 57 minutes of sauna exposure per week is enough to see health benefits.“
– Susanna Søberg, PhD
What is Contrast Therapy?
Contrast therapy involves the exposure of the body to hot temperatures (ex. sauna, hot bath) followed by cold temperatures (ex. cold plunge, ice bath) in quick succession. For example, 10 minutes of sauna, followed by a 2 minute ice plunge, then repeat the process once or twice more. The rapid changes in temperature stimulate the circulatory system and enhance recovery, helping to reduce pain, muscle soreness, and fatigue.
Humans consistently maintain a core body temperature of around “37 +/- 0.5°C (98.6 +/- 0.9°F)” for healthy metabolic functioning1. This process is called thermoregulation, where your core body temperature is balanced through the generation and loss of heat. The brain’s hypothalamus, specifically the hypothalamic thermoregulatory center located in the preoptic area, functions like the human body’s thermostat regulating and setting temperature homeostasis1.
Inside the hypothalamus there are temperature sensors called peripheral and central thermoreceptors; these are nerve cells that receive information from important parts of the body. The peripheral thermoreceptors sense surface temperatures and carry this information from the skin. The central thermoreceptors sense core temperature and signal from the spinal cord, viscera, and hypothalamus. When the body temperature changes, these thermoreceptors activate and inform the mechanism to regulate the temperature by increasing or decreasing heat returning it back to baseline1.
The Healing Heat
With that in mind, exposure to hot temperatures like that of a sauna (around 150-175℉, or 65-90℃) through the activation of these mechanisms of thermoregulation trigger the release of powerful hormones such as endorphins and dopamine, and if you stay in long enough the release of dynorphin. These neurotransmitters are associated with improved mood, reduced anxiety, and a greater sense of wellbeing. The heat promotes relaxation by decreasing cortisol level producing a kind of “post-therapy high” that provides a natural mood boost similar to the effect of exercise. Interestingly, paying attention to the sensations of heat on your skin, your breathing, and how your body responds one can cultivate a state of mindful awareness. The benefits of sauna are constantly being discovered and along with it holds as one of the easiest and most cost-effective ways to positively contribute to your overall health.
Exposure to cold water below 15 degrees for sustained periods can induce thermal stress to the body which lowers skin and core body temperatures. This thermal stress activates the Sympathetic Nervous System (SNS) triggering the release of neurotransmitters and hormones driving a response, aka your body’s fight-or-flight response. The body’s natural response to dropping temperature is to regulate the imbalance in core temperature by heating the body back to homeostasis. Through SNS neurochemical release, vasoconstriction & vasodilation, and brown fat activation one can experience many health benefits. In particular, consistent practicing of CWT over time rewards one with a greater ability to adapt and deal with stress by utilizing deep controlled breathing techniques that increase focus and concentration. Most of the perceived benefits surround the internal battle with the cold stressor, when one pushes through that cold mental barrier one can naturally build their mental resilience, emotional regulation, and self-control.
Harnessing the benefits of both extremes
The key to harnessing the benefits of both extremes is in the rapid changes produced in your circulatory system when you go from very warm temperature to very cold temperature. When you submerge part or all of your body in cold water, small blood vessels called capillaries respond to the cold by getting smaller. This is known as vasoconstriction. When you immerse yourself in warm water, the opposite happens. Your blood vessels open up. This is known as vasodilation. Different water temperatures also cause changes in how fast your heart beats, cold water causes your heart rate to speed up, while hot water slows it down. The fluctuation between hot and cold exposure activates the nervous system, increasing blood flow and creating a cycle of endorphin release which as we know have their benefits.
Extension: Uncommon knowledge
In addition to that, there is a point when your brain tells you you’ve reached your threshold in these extremes. If you’re not familiar with this feeling, it’s when you really want/need to get out! By pushing through that little bit longer another important and often overlooked hormone would be released. Dynorphin is a natural opioid produced in times of unease which helps mediate the response to heat or cooling the body. After pushing past this feeling there is a cascade of processes that make your feel-good endorphins (beta) a lot sharper, sensitizing them and increasing future endorphin exposure.
In my opinion this would also strengthen the Anterior-Midcingulate-Cortex (aMCC) part of the brain, also known as ‘The Goggins Muscle’ coined by neuroscientist Dr. Andrew Huberman of Huberman lab. In a nutshell, this is the muscle in your brain that grows and strengthens the more you make decisions to do hard or difficult things – the more you exercise it the easier and stronger your ability to do hard things gets.
Benefits of Contrast Therapy
Aside from its popular physical health benefits such as circulation, muscle recovery and soreness. Contrast therapy also promotes mental well-being by improving focus, reducing stress, and enhancing cognitive performance. It helps to develop mindfulness and mental resilience by requiring focus on bodily reactions and breathing, promoting awareness and better sleep, all the while improving mental alertness and builds tolerance to physical and emotional stress.
Physical, Emotional, Spiritual, and Social Benefits:
- Improved circulation: The temperature changes stimulate blood flow, promoting better oxygen and nutrient delivery to muscles and tissues.
- Reduced inflammation and soreness: Cold exposure helps reduce swelling, while heat relaxes muscles, aiding in recovery after physical activity.
- Enhanced muscle recovery: The alternating temperatures speed up the removal of waste products, reducing muscle fatigue and promoting faster recovery.
- Boosted immune function: The therapy may help stimulate the immune system by improving lymphatic drainage and reducing inflammation.
- Stress relief and relaxation: The hot and cold shifts promote relaxation, reduce stress, and enhance mental clarity and alertness.
- Improved sleep: By regulating the body’s circadian rhythm, it can lead to better, more restful sleep, which is crucial for mental health.
- Strengthened mental resilience: Regular exposure to discomfort, such as hot and cold shifts, builds tolerance to physical and emotional stress, helping you cope better with challenges in everyday life.
- Increased mindfulness: Alternating between hot and cold requires focusing on your body’s reactions, enhancing present-moment awareness and mindfulness.
- Community and social health: Many people practice sauna use, ice baths, and contrast therapy in group settings. The shared experience of enduring these physical challenges can strengthen social bonds, reduce feelings of isolation, and foster a supportive environment.
How to Do Contrast Therapy
There is no perfect way to perform contrast therapy! People do it for various reasons, and have different tolerances to temperature extremes etc. However, many sources agree upon the following procedure. To perform contrast therapy, begin with exposure to heat (37-42℃) for 2-10 minutes, followed by cold immersion (10-15°C) for 1-3 minutes. Repeat the cycle 3-4 times, ensuring adequate rest between sessions.
Safety Precautions During Contrast Therapy Sessions
It’s essential to listen to your body and avoid extremes if new to the practice. You can use a thermometer or temperature measuring device to gauge the temperature. Alternating between a larger and more extreme temperature range at a beginner level can dangerous if your unprepared. For example, I’ve experienced a thunderclap headache during contrast therapy going from 70 ℃ to 4℃. This was proper nasty and last for 1-2 days so tread carefully.
Although people do contrast therapy under the supervision of a therapist, coach, or friend it’s possible to try it on your own. But, check with your doctor or a medical professional first to make sure it’s safe for you.
Quick Tips For Your First Contrast Therapy Session
- Start slow: Do shorter exposure/immersion times for both hot and cold temperatures. A good starting place could be a 5 min sauna @ 65 degrees followed by a 1 min cold plunge @15 degrees. Increase temp, length and frequency gradually as your body adapts.
- Stay hydrated: Drink plenty of water a few hours before. Remember, small sips during and between, and after sessions to avoid dizziness, fatigue and other symptoms related to dehydration.
- Listen to your body: Contrast therapy is about tuning into your body, paying attention to how it feels throughout the session. If you’re extremely uncomfortable with the temperature, or lightheaded you may need to start slower or take a break. It’s not a competition, it’s about your own personal development so start slow.
- Warm up first: Ensure the body is warmed first by spending extra time in the hot phase of the session for the first few sessions which helps prepare your body for the transition into the cold temperature.
- Have an exit strategy: Prepare for post contrast therapy by either, having a towel with warm clothing handy to recover from the cold phase. A pro tip here would be performing the Wim Hof warming method where you move and breath to let your body warm up naturally rather than using a towel or clothes, this helps the body develop and build resilience toward temperature faster.
Trusted Sources
Like the internet sensation Wim ‘The Ice Man’ Hof, many professionals in the field have become huge advocates for contrast therapy, often orientating their research towards their benefits. Its super important to have properly informed knowledge when intentionally inducing stressors to your environment. So, my service to you is providing you with two very quality scientific sources that will provide you with any further knowledge for your contrasting journey.
Andrew Huberman (Huberman Lab) on Contrast therapy
Neuroscientist Andrew Huberman has shared his personal experiences with contrast therapy, praising its benefits for mental clarity, physical recovery, and stress reduction. Huberman focuses predominantly on the cognitive and mood-enhancing effects as they are not as well recognized in the field of hot, cold, and contrast therapy.
Recommended Article: Heat Exposure and Cold Exposure to Optimize Health – Huberman Lab
Recommended Poddy: Dr. Susanna Søberg: How to Use Cold & Heat Exposure to Improve Your Health | Huberman Lab Podcast (youtube.com)
Susanna Søberg’s Contrast Therapy Research
Dr. Susanna Søberg is a research pioneer in the field of thermoregulation and temperature-based therapies. Her research highlights the significant metabolic and psychological benefits of contrast therapy with studies that show improved insulin sensitivity, fat metabolism, and increased production of norepinephrine, which enhances mental resilience and mood regulation. She discusses how contrast therapy is an excellent recovery tool for athletes and expresses some words of caution about how everyone is different with their needs and limits.
Recommended Article: Dr. Susanna Søberg: How to Use Cold & Heat Exposure to Improve Your Health | Huberman Lab Podcast (researchhub.com)
Recommended Poddy’s
Cold Therapy: Reduce Stress and Sleep Better | Jim Kwik & Dr. Susanna Søberg (youtube.com)
Heat Therapy for Limitless Health | Dr. Susanna Søberg (youtube.com)
Risks Associated with Contrast Therapy
While contrast therapy offers numerous benefits, it can pose risks for individuals with cardiovascular issues or cold sensitivities. Abrupt temperature changes may strain the heart, so those with pre-existing conditions should consult a physician before starting. “Cold and heat can impair the human body and its physiological processes in innumerable ways, while also interacting with pre-existing conditions and chronic diseases. With both exposures, the primary concern is alteration of the body’s core temperature beyond a healthy range”. It is therefore imperative that beginners should ease into the practice to avoid shock or discomfort.
Other symptoms of risk:
- Dizziness, fainting, or thunderclap headache due to sudden temperature changes
- Dehydration from sweating like a fountain in the sauna
- Risks for individuals with pre-existing conditions
Conclusion
In sum, incorporating both hot and/or cold temperatures into your wellbeing routine can be a powerful way to bolster your overall health. Contrast therapy adds an extra element of resilience and mental toughness to the wellness regime aswell as enhancing recovery, reducing stress, and improving overall wellbeing. With a steady flow of research supporting its benefits, contrast therapy has become an immensely popular wellness practice helping improve the lives of humans all around the world.
References:
The Healing Chill: Health benefits of Cold-Water Therapy (domfransen.com)
Healing Heat: Sauna types and health benefits (domfransen.com)
Heat Exposure and Cold Exposure to Optimize Health – Huberman Lab
Peer reviewed references:
Dudzik, T., Dudzik, Ł., Kozieł, A., & Domański, I. (2024). The Impact of Sauna on Health. Journal of Education, Health and Sport, 69, 49430-49430.
Laukkanen, J. A., Laukkanen, T., & Kunutsor, S. K. (2018, August). Cardiovascular and other health benefits of sauna bathing: a review of the evidence. In Mayo clinic proceedings (Vol. 93, No. 8, pp. 1111-1121). Elsevier.
Osilla, E. V., Marsidi, J. L., Shumway, K. R., & Sharma, S. (2023). Physiology, Temperature Regulation. In StatPearls. StatPearls Publishing.
Patrick, R. P., & Johnson, T. L. (2021). Sauna use as a lifestyle practice to extend healthspan. Experimental gerontology, 154, 111509.
Seltenrich, N. (2015). Between extremes: health effects of heat and cold.