by Jes Williams @feelmoregooder
Modern day “contrast therapy” or the “nordic cycle” as it is sometimes referred to, is the practice of exposing the body to cold and hot temperatures back to back (though separately) to improve health, boost the immune response, and more.
These practices have made their way into the mainstream - with more brands than ever manufacturing cold plunges and sauna. We want to break down some of the specifics for you, and give you a better idea of what someone can expect when they engage in either of these.
Intro to Contrast Therapy
Following your sauna session with a cold plunge (or visa versa) is not required to get the benefits of each, but it’s worth touching on - since it has gained popularity in recent years as an adjunct mainly for sports training and exercise recovery. It’s sometimes referred to as the “Nordic cycle.”
This hype is for good reason, as the literature shows many health benefits. (3, 4) One application that has become commonplace with athletes is using this an an effective method to prevent DOMS (delayed onset muscle soreness). (1) The practice of contrast therapy (in this study it was specifically referencing alternating cold water and hot water immersion) is shown to reduce oedema by alternating peripheral vasoconstriction and vasodilation. This action creates a “pumping” or “flushing” reaction within the body. (1)
Additionally, it is interesting to note that this practice is not new - it has been commonly practiced in some cultures for thousands of years, with many scientific studies done (5):
“In addition to heat stress induced by sauna bathing, intermittent heat and cold exposures are a quite common practice, for instance in Finland and other Nordic countries, when sauna bathing.” (2) This study notes that this is normally practiced by going outside in a cold environment between sauna sessions.
Benefits of Sauna
Incorporating regular sauna sessions (also called sauna bathing) is associated with many health benefits, ranging from cardiovascular and cognitive health to physical fitness and muscle maintenance. (6)
Exposure to a hot environment elicits release of heat shock proteins in the body, which are shown to be protective against neurodegenerative diseases, moderate muscle atrophy, help repair proteins that have been damaged, and offer protection against cellular stress). This heat stress via sauna use elicits hormetic responses driven by molecular mechanisms that protect the body from damage. These effects are similar to those elicited by moderate - to vigorous-intensity exercise, and may offer a means to haltl the effects of aging and extend healthspan. (6)
Additional benefits of sauna use include:
- -Protection against cardiovascular diseases
- -Prevention of multiple neurodegenerative diseases
- -Reduced risk of all-cause mortality
- -Positive impact on circulatory system
- -Improved immune response
- -Modulation of autonomic nervous system
- -Lowers systemic blood pressure
- -Improved mitochondrial function
Most of this research is done on Finnish sauna practices (a large wooden sauna with a central stove unit). Studies show that this is practice is a “recommendable health habit.” (7, 8, 9, 10, 11, 24)
Traditional vs Infrared
Many have their preference here as far as the type of sauna they prefer. While most studies are done on a traditional sauna, some literature suggests that infrared saunas offer benefit, too. (12)
However, it makes sense that the benefits may differ slightly, as infrared saunas do not typically get as hot as traditional saunas - thus the circulatory and heat-shock protein related perks may vary. Too, the actual make-up/heat source of the sauna comes into play.
For instance, the infrared benefits from a sauna you plug into a power grid can also be gained from exposure to fire (which some modern sauna tents/apparatuses offer) - without the downside of non-native EMF exposure.
Did you know? Over 50% of the sun’s power output is infrared light. Too, your own body even produces its own infrared wavelengths. (13, 14) These wavelengths naturally present in the sunlight offer many systemic benefits to the body.
Some may opt for a traditional sauna to reach higher temperatures, and get the benefits of infrared heat through fire (via a sauna tent) and/or intentional harmonious time spent outside and/or sunbathing - in order to get their infrared from a more natural source.
A 2024 study highlight the specific perks of Finnish Saunas: “The Finnish saunas have the most consistent and robust evidence regarding health benefits.” The study goes on to mention that this method is shown to decrease risk factors related to cardiovascular health, cognition, braing function, respiratory conditions, musculoskeletal disorders, common seasonal ailments, sleep, mental well-being, and longevity. (17)
Benefits of Cold Exposure
Making up the other half of a so-called “Nordic cycle” is cold exposure - which can be practiced in a few different ways, like sauna bathing. It is clear in the literature that there is increasing scientific support that voluntary exposure to cold water may have some beneficial health effects. (15)
Perks of Cold Exposure:
- -Better resilience to stress
- -Beneficial effects on the cardiovascular system
- -Protection against insulin resistance
- -Improved mental state/health
- -Alleviates pain
- -Brings down systemic inflammation
- -Enhances mitochondrial biogenesis
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-Activates brown fat, which is associated with improved oxidative capacity and lower body weight (2, 15, 16, 25)
Something else of note when comparing practices like cryotherapy (surrounded by cold air) to an ice bath (water immersion) is that cold air has a lower coefficient of heat transfer than cold water. So, to extract the same heat from the body, cold air requires much colder temperatures. In other words, cold is more effective for this reason. More on this in the next section of this post.
Cold Water & Hot Air Is the Ideal Combination?
Contemplating all of the different ways to put your “Nordic cycle” habit into place? Here’s something to consider. A 2020 study shows us that contrast bath therapy (using water as the heating or cooling source) were both effective in increasing blood flow, reducing muscle stiffness, increasing muscle elasticity, and relieving pain.
However, we know that water is considered better than air for cold exposure because it transfers heat away from the body significantly faster due to its higher thermal conductivity. This means that water can extract heat from your body much more efficiently than air at the same temperature. So, if you have access to either method, water is the better choice.(22)
Logically, it makes sense that air may have a leg up on water in terms of heat exposure, as you do not want heat loss. Thus, you’d choose the medium through which you can maintain heat more easily (air/sauna).
Polyphenols for Mitochondrial Health
In addition to the other positive effects they have on the body, both cold plunge and sauna practices are beneficially impactful to the quantity and healthy of the mitochondria in your cells.
Other ways to support your mitochondria include adding in plant compounds like sulforaphane, quercetin, resveratrol, curcumin, and berberine - each of which have been shown to support mitochondrial efficiency in various ways. You can find these beneficial plant constituents (polyphenols) in our product line.
Concluding Thoughts
If you find yourself getting caught up in the details or a “paralysis analysis” if you will, just know that doing what’s available to you likely comes with healthful benefits. The whole idea is to put your body in an environment where it must thermoregulate.
For instance, cold showers (available to anyone with a functioning bathroom) are a great entry point for cold adaption, even though the benefits may vary slightly from cold water immersion or cryotherapy. Even walking outside underdressed during the winter months is a form of cold exposure. There appears to be some (in many cases trivial) differences between cold air versus cold water, but some of the literature suggests the idea of experimenting with both and/or combining them into a routine. (20)
Additionally, though most studies are done on saunas - hot tub bathing (for example) is ingrained into the culture in Japan. (19) A 2013 study shows us that “the greatest pain reduction was shown after immediate application of moist heat.” - perhaps making the use of the stove ladle in the sauna stove advisable. (21) Thus, if your aim for incorporating sauna is to improve athletic recovery, perhaps you play with both a humid sauna and hot tub.
However, there is some science saying that a sauna (hot air) offers some unique benefits over hot water therapy (hot water). Hot tubs are shown to have a beneficial impact on relaxation levels as well as insulin response (26), while saunas are shown to target detoxification and metabolic efficiency through the often more intense temperatures and sweating. (12) Studies comparing the two side by side are lacking, but hopefully they will emerge as sauna usage continues to become more prevalent.
References:
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https://journals.physiology.org/doi/full/10.1152/ajpregu.00115.2017
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https://www.sciencedirect.com/science/article/pii/S0531556521002916
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https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2130724
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https://journals.physiology.org/doi/full/10.1152/ajpregu.00115.2017
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https://scied.ucar.edu/learning-zone/earth-system/types-of-energy
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https://www.health.harvard.edu/heart-health/hot-baths-and-saunas-beneficial-for-your-heart
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https://journals.physiology.org/doi/full/10.1152/ajpendo.00222.2023
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https://www.sciencedirect.com/science/article/pii/S221345302300188X
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