From hot springs to sweat lodges to saunas, the power of heat has been used throughout human history to address human ailments, detox, and support overall health - and for good reason! As it turns out, the human body holds a slew of superhero genetic tools which, when activated, can tackle a host of health issues, and with very little conscious effort on your part! All you have to do is embrace the heat!
Let's be honest: our bodies have become more inclined to sloth than strength. Today's modern environment yields a cushioned facade of comfort, yet chronic mental stress runs rampant, which actually encourages both mental and physical damage on our bodies. But this damage is not entirely our "fault," as we often lack one of the most powerful stimulants of health: intense physical stress. Exposing our bodies to extreme conditions, like periods of starvation, or frigid or burning temperatures, signals to the body that it needs to rise to the challenge and protect itself, via the activation of a myriad of different protective genes. This can happen with cold exposure's activation of sirtuins and cold shock proteins, as well as with heat exposure, which initiates heat shock proteins. These heat shock proteins boost resilience in the body by repairing damaged proteins, getting rid of gunk, and otherwise cleaning up cellular shop!
Studies have found heat shock proteins boast myriad benefits, including boosting the body's natural antioxidant production, discouraging free radicals, reducing damage to cells, and much more! Think of it as what doesn't kill you, makes you stronger! As a 2018 systemic review published in Evidence Based Complement Alternative Medicine notes, "Sauna bathing may induce a general stress-adaptation response that leads to 'hormetic adaptation' and the establishment of 'sauna fitness,' possibly analogous to the hormetic adaptation responses of exercise." Pretty nifty!
Heat exposure itself can also improve blood flow and increase nitrous oxide in the blood, while decreasing systolic blood pressure. In fact, heat can have a modulation effect on the entire nervous system - from the hypothalamus to the central nervous system to the autonomic nervous system - reducing inflammatory prostaglandins and stress hormones like epinephrine and norepinephrine. While, in the short term, a sauna session may actually create some free radicals and reactive oxygen species, it also boosts the body's antioxidant system, resulting in an overall empowering effect.
From the body to the brain to the heart, let's dive deeper into some of sauna's sparkling benefits!
One of the sauna's most applauded benefits resides in its remarkable effects on the heart, comparable to exercise! Studies on sauna sessions show improved markers of cardiac function across the board, along with improved flow and blood vessel dilation. A variety of potential mechanisms may explain this. The heat from a sauna session can dilate arteries to improve vascular endothelial function, ramp up endothelia nitrous oxide synthesis, and activate voltage-gated calcium. It also may support the heart by reducing oxidative stress, and stimulating miRNA genes, which function as anti-inflammatories.
Perhaps most importantly, it's not just markers in a lab which improve: a multitude of studies show measurable outcomes in health conditions and related fitness. For example, a randomized controlled trial of 149 patients with congestive heart failure found that two weeks of sauna sessions improved walking distance, reduced heart size, and led to more favorable disease classifications, whereas the control group saw no such changes. Another study on babies with congestive heart failure, found that five-minute sauna sessions for a month eradicated the need for surgery! Other studies have found sauna therapy can reduce premature ventricular contractions in those with ventricular arrhythmias.
Extremely fascinating, some of the cardio-protective effects of sauna may be thanks to its effects on cholesterol levels. One study in healthy men found that a month of 45-minute sauna sessions reduced total cholesterol levels, increased the "good" HDL, and reduced the "bad" LDL, while another study found 2 weeks of 30-minute sessions reduced LDL in healthy women.
Speaking from experience, a sauna session can have a profound effect on acute and chronic pain. A 2005 study of 46 Japanese patients with chronic pain, found that those who underwent a behavioral, rehab, and exercise therapy treatment protocol which included a 4-week sauna treatment, were more likely to return to work two years later compared to those who did not receive the sauna session, yet received the other parts of the treatment protocol. A 2012 New Zealand study found that six weeks of sauna session treatment lead to 44% reduced headache intensity in patients with chronic tension headaches, while a 2011 Japanese study on patients with fibromyalgia, found reduced pain and improved quality of life after three months of infrared sauna sessions combined with exercise therapy. Lastly, in a 2009 Dutch study, a month of sauna therapy decreased stiffness and pain in patients, although notably the pain relief only lasted as long as sessions were sustained. In other words, you might want to make sauna a regular part of your habits, if pain relief is the goal - completely attainable with at home infrared saunas, as we'll discuss in a bit!
Fatigue, Mood, And Stress
While the idea of exposing oneself to intense heat may sound draining, a sauna session can actually have an overall energizing effect on the body - physically and emotionally. This is especially often the case with infrared versions, which utilize lower temperatures (more on that in a bit!) Studies on patients with chronic fatigue syndrome have found that sauna sessions may decrease fatigue, and reduce the taxing mental distress of anxiety and the low energy state of depression. In a 2015 study, almost 80% of patients who underwent two months of infrared sauna sessions reported reduced depression.
Sauna sessions may foster these mood-boosting benefits by literally stimulating the release of happy brain chemicals like endorphins and the opioid peptide dynorphins. Additionally, the relaxation and mindfulness of a sauna session, coupled with improved sleep, can further encourage overall positive psychological effects. In my own experience, perhaps the greatest mood boosting effects of the sauna session is the overwhelming sense of calm and peace I experience with each nightly session, which further reinforces itself as ritual. As a 2020 article published in F1000 Research theorizes, "The exploration of heat-tolerance induces a 'forced-mindfulness,'" and "engaging in an activity with an intended positive outcome can also impart feelings of control that may otherwise be lacking... doing something that feels good and having positive expectations elicits the power of positive thought and the placebo effect or ‘remembered wellness.’"
As one final plug for brain health, studies have also linked sauna use to reduced rates of dementia and Alzheimers!
While it's true that a person can lose a substantial amount of weight in a sauna session, the majority of this weight loss is simply water weight. That said, the sauna may instigate quite a few beneficial effects on our metabolism and body composition, ultimately encouraging more weight loss in the long term! Sauna sessions have been shown to decrease blood sugar levels and increase insulin sensitivity, which are important for metabolic health. Sauna sessions may also stimulate growth hormone, important for the maintenance of lean body tissue. As for calories (because I know you want to know!), studies have found a sauna session may "burn" around 70 to 150 calories in ten minutes, with extended use burning more - meaning you'll likely burn more in the last ten, rather than the first ten, minutes of your sauna session. Those with higher weights and body mass also tend to burn more than leaner individuals.
The effects of sauna on the body are even comparable to physical exercise in many ways! As a 2018 review notes, "it has been suggested that heat stress induces adaptive hormesis mechanisms similar to exercise." From a heart rate perspective, the "physical effort" of sauna sessions can reach the "difficult range" comparable to exercise.
I personally came to saunas for the detox, and stayed for all the other benefits! I suffered with severe mercury toxicity, and aggressively sought all means possible to rid the toxic heavy metal from my body. (Check out my blog post Mercury Madness: Exposure Sources, Safe Fish Consumption, Chelation, EDTA/DMPS/DMSA, Detox, Amalgams, The Cutler Protocol, Glutathione, And More! for all the details!) A powerful way to excrete toxins is via our sweat, which obviously ramps up in a saunas session! Sweating can excrete heavy metals, pesticides, and other phytochemicals, in amounts rivaling or even exceeding that seen through the typical route of the urine. While more studies are warranted, some have found that sauna sessions produce significant effects in subjective health symptoms, in those individuals with high toxic burdens, after sauna sessions. In a 2012 study with policemen experiencing negative symptoms from high toxicant levels, four to six weeks of infrared sauna sessions lead to reduced sick days, greater sleep, and fewer symptoms of neurotoxicity.
To maximize your sauna session's detox potential, you can follow a heat session with a cold shower, which will shuttle blood to the internal organs, increase diuresis, and ramp up detox!
Epidemiological studies consistently find correlations between saunas and reduced viral infection. There are likely a number of reasons for this. High temperatures can potentially directly deactivate viruses and support their clearance via mucus in the respiratory track. If the viruses do manage to take hold, fevers in the body serve as a natural defense mechanism against the infection. Inducing an artificial fever in the body during a sauna session may therefore help wipe out viruses systemically.
Randomized trials have found that heat above 43°C (109.4°F) for 20 to 30 minutes can reduce virus replication, relieve viral symptoms, and improve recovery. Additionally, the high temperatures from a sauna may activate immune cells, expedite the body's viral response, increase TNF-alpha monocytes, and increase T-lymphocytes. The aforementioned heat shock proteins are also vital in activating parts of the immune systems like macrophages and dendritic cells, while protecting immune cells from any heat damage.
Recent research has even turned to heat as a potential treatment for COVID. Enveloped viruses such as SARS-CoV-2 thrive in cool, dry environments, and can remain active in such for a substantial amount of time. Yet they are heat sensitive, and can be destroyed by temperatures which humans can tolerate, particularly 55°C to 65°C (131°F - 149°F) for 15 to 30 minutes. Saunas may also alter the blood's pH to create an alkaline state, which can aid immune system defense. For example, the virus MHV-A59, also in the corona family, can be irreversibly deactivated when exposed to an alkaline pH of 7 at 37°C (98.6°F). Far infrared wavelengths (such as those used in infrared saunas) have also been shown to deactivate RNA viruses.
In particular when it comes to COVID, heat stress can have a beneficial effect on the lungs, including ventilation, volume, and capacity. A 2014 study on patients with chronic obstructive pulmonary disease, found increased lung performance after a month of sauna sessions compared to control, while a 2008 study in a group of ex-smokers, found a month of of sauna sessions decreased pulmonary artery pressures during exercise, increased exercise performance and oxygen saturation, and improved the body's systems overall.
USING A SAUNA
Ready to bring some sauna sessions into your life? Here are all the details!
Traditional Vs Infrared
In a traditional wet or dry heat sauna (such as Finnish saunas), the body is heated from the ambient temperature from the outside in, with temperatures ranging around 80°C – 100°C (176°F - 212°F). In these scenarios, you must endure some extreme temperatures (and consequently perceive it as such!) to experience the benefits. Infrared saunas, on the other hand, use infrared wavelength energy (typically in the mid to far infrared range, though occasionally with near infrared wavelengths as well), to heat cells from the inside out. These temperatures range from around 49°C - 60°C (120°F -140°F).
This means that with an infrared sauna session, you can effectively achieve the benefits of heat shock proteins, cardiovascular stimulation, and more, without necessarily feeling that hot. It's sort of like how you can have a fever, yet not necessarily feel hot. But unlike the distressing and unpleasant feelings you may have when suffering a fever, an infrared sauna actually feels amazing, warm and calming! You'll likely end the session feeling relaxed, rather than overwhelmingly drained and dehydrated. While a traditional sauna may be too much for some people to handle every day, most people can easily have a nightly infrared sauna session, especially if it's in the comfort of their own home!
I also love the maintenance aspect of infrared saunas! No water is required to heat them, and they are effectively "self sanitizing!" Unlike the warm, moist environments of traditional saunas, with infrared saunas you don't have to worry about mold growing. (Thank. Goodness.)
Sunlighten ($200 off!)
I did a lot of research when looking into infrared saunas. My main concerns were quality, EMF exposure, and accessibility. When I found Sunlighten, I knew I had arrived! Sunlighten makes an array of infrared saunas to fit any need. Their units have been tested for EMF radiation! (See their full 3rd party Vitatech report here. ) I personally fell in love with Sunlighten's Solo System: a collapsible unit you lie in! It's fantastic for those living in apartments or not wanting to invest in a full sauna. It also features chromotherapy around the rim for mood! (I bought this twin size metal frame to set it on!) I also got their far infrared pad to lay on, as well as their toxin-absorbing bamboo carbon towels.
After purchasing a Sunlighten for myself, I invited the founder Connie Zack on the Melanie Avalon Biohacking Podcast to quiz her about all the science! I was blown away by Connie's personal story and passion: she came to the benefits of sauna after her brother experienced overwhelming health issues. She she saw the power of sauna to empower people to take charge of their health conditions. I can attest that the Sunlighten company truly bears a heart of gold, and I am so grateful that they have made my nightly sauna session possible.