What are the benefits of using a sauna? There’s no getting around it, the sauna is a hot topic right now. Puns aside, it seems like every gym, recovery center, and hipster home has a sauna and cold plunge laid out in luxury fashion or rigged up in the backyard, but can sauna really live up to the hype? Or is it just the most recent fad in a long line of biohacking click bait articles? Are there specifics on how long you should sauna for, how frequently, and at what temperature?
The short answer: Yes, sauna lives up to the hype and then some. The amount of research on sauna is surprising, and the studies speak for themselves, there are a number of benefits of using a sauna. But first it’s important to know what kind of sauna the research has primarily looked at so that you understand how to maximize your health and longevity through this storied recovery modality.
Table of Contents
The Different Types of Saunas
1.) Dry Saunas
This is the classic wooden sauna that’s been popularized by the Finns and adopted by the American health and wellness scene. The temperatures are high, about 176-212℉ (80-100℃), but the humidity remains lower, around 10-20% [1]. As the most commonly used and commonly researched type of sauna, the dry sauna will be the one we are referring to when discussing the various benefits and few caveats of saunas in this article.
2.) Steam Sauna
The steam sauna relies mostly on, you guessed it, steam. The temperatures are lower, about 110-120℉ (43-49℃), but the humidity is near 100%. While steam saunas have benefits like clearing mucus, it’s unclear if the temperatures are high enough to convey the same health benefits as a traditional dry sauna [2].
3.) Infrared Sauna
Far-infrared saunas penetrate deeper into the human body which allows them to work at a lower heat, around 120-140℉ (49-60℃). Infrared saunas may help lower pressure and be used as a therapy for congestive heart failure, however the research on the benefits of infrared saunas is still limited in comparison to that of traditional dry saunas [3].
Now that we’ve covered the different types of sauna and clarified that we will be discussing the traditional Finnish dry sauna in this article, let’s discuss some of the benefits of using a sauna.[1]
10 Health Benefits of Using a Sauna
1. Decreased risk of cardiovascular disease
Regular sauna bathing, like regular exercise, can help decrease the risk of dying from cardiovascular diseases like coronary heart disease, stroke, or heart failure to name a few. In fact, one study showed that 2-3 times per week was associated with a 25% decreased risk of dying from cardiovascular disease, while regularly hopping in the sauna 4-7 times per week was associated with a decreased risk of dying from cardiovascular disease by a whopping 77%! [4]
2. Decreased risk of respiratory diseases like pneumonia
A 2017 study found that men who sauna bathed 2-3 times per week decreased their chances of developing a respiratory disease like pneumonia, COPD, or asthma by 28% [5]. Men who sauna bathed 4 times a week or more had a 37% decrease in developing a respiratory disease [5].
3. Decreased risk of some mental health disorders
A 2019 prospective cohort study found that there was an inverse relationship between sauna and psychosis, aka the more you sauna, the lower your risk of certain mental health disorders like major depressive disorder, neurodegenerative disorders, and schizophrenia [6].
4. Decreased risk of Alzheimer’s and dementia
Even as little as 1 sauna session per week has been associated with a 65% decrease in developing Alzheimer’s and dementia as reported by a 2017 Finnish study [7].
5. Improved cholesterol levels
Similar to diet and exercise, multiple studies have shown that sauna can improve cholesterol levels, decreasing LDL Cholesterol, which is largely responsible for the plaques that build up in arteries and can increase the chance of developing heart disease, while simultaneously increasing HDL, the cholesterol that scavenges LDL form the arteries, decreasing the chances of cardiovascular disease [8,9].
6. May decrease pain
Some studies have shown that saunas can help relieve joint and muscle pain, like rheumatoid arthritis, [10,11,12], although this pain relieving effect may be more prevalent in men than women, and sauna may actually exacerbate pain in 25% of women [12].
7. May decrease intensity of headaches
At least one study has suggested that sauna bathing can decrease the intensity in chronic headaches [13].
8. Increased release of growth hormone
Sauna bathing increases the release of Growth Hormone, which is responsible for increasing lean muscle mass, reducing body fat, improved VO2max and power output [14]. In one study, subjects who sauna bathed twice daily for an hour each session with a 5 min cool down period after 30 minutes experienced a 16x increase in Growth Hormone secretion in men, and a 2.3x increase in women [15]. This increase subsided by day 3, suggesting our bodies adapt to the stress of the sauna, suggesting that if your primary goal for sauna bathing is to release growth hormone, it might make more sense to do longer sessions broken up with a 5 minute break once a week in order to maximize growth hormone release. This increase in Growth Hormone secretion is likely more pronounced in men than women, and may only occur in men under the age of 50, since we secrete less growth hormone as we age [16].
9. May improve endurance
Regular sauna bathing may also increase athletic performance. One study reported that after 3 weeks of sauna bathing the average time to exhaustion for 6 distance runners improved by 32%, which the authors theorized might lead to a 1.9% in an endurance time trial [17]. This improvement was likely through an increase in total blood volume [17]. Similarly, another research study found that a single sauna session improved the body’s natural antioxidants by a little over 8%, and decreased oxidative stress, which may help with post workout recovery, although it’s unclear if those antioxidant benefits persist over the long term [18].
10. Decrease in all cause mortality
Lastly, and perhaps most importantly, regular sauna bathing has been associated with a substantial decrease in all cause mortality, or the number of deaths we would expect to see in a specific group of people over a specific amount of time. Like having a regular exercise routine, it’s well documented that sauna can help decrease the risk of dying from cardiovascular disease, but sauna also decreases your chance of dying from any disease compared to people who don’t sauna [19]. Enjoying a sauna 2-3 times per week was associated with a 24% decrease in all cause mortality, while sauna bathing 4-7 times per week was associated with a 40% decrease in all cause mortality! [19]
How sauna improves health, longevity, and performance
There are a few different hypotheses as to the underlying mechanisms that result in the many benefits of using a sauna, although the research in this area is still emerging. Perhaps the most likely source of many of these benefits are Heat Shock Proteins, which are activated by stress, and especially high temperatures, like the ones experienced in a sauna.
Heat Shock Proteins (HSPs) help proteins fold correctly, which improves cell function, creates new cells, and prevents existing cells from being destroyed by environmental factors like heat and hypoxia (lack of oxygen) [20,21,22]. Since proteins are a critical part of the infrastructure of cells, and help carry out the function of most cells as enzymes and hormones, the role of Heat Shock Proteins is critical to ensure cells function properly and optimally.
Sauna also naturally increases the amount of growth hormone the body releases [15]. Growth hormone is responsible for a number of important functions in the body including building muscle, burning fat, and improving VO2 Max and maximal power outputs [14].
An increase in endurance may occur due to an increase in blood volume that accompanies heat acclimation, as may be the case with frequent sauna bathing [17]. Additionally, sauna bathing may decrease oxidative stress on the body by increasing the number of natural antioxidants that the body has to defend against oxidative stress [18].
Risks of sauna
Sauna has a number of health benefits, including improved cardiovascular function, improved cognitive function, and an overall association with better health and longevity [10,11], however, there are a few risks associated with sauna, but it’s important to note that the research is inconclusive on these risks at the moment and that more studies will need to be performed to better understand which of these risks, if any, need to be considered before adopting a sauna bathing routine. Lastly, it’s important to note that while this article is meant to be informative, it is not meant to be instructive, and you should consult your doctor before experimenting with sauna bathing.
With the legal disclaimers out of the way here are the potential risks of sauna.
Temporary decreased male fertility is cited as the most common risk with sauna [23, 24]. While it’s true that increased temperature on the scrotum can negatively affect sperm concentration, sperm DNA, and sperm motility, the evidence is conflicting and researchers disagree whether sauna causes a temporary decrease in male fertility [25,26]. Regardless, in the studies that have shown a decrease in male fertility as a result of frequent sauna use, sperm counts, and sperm motility returned to pre-sauna levels 90 days after sauna cessation [24].
In addition to a potential decrease in male fertility, there is often a concern that sauna use may be dangerous for those who have experienced a heart attack, stroke, or have congestive heart failure, however, the research suggests that sauna is safe for people who have experienced a cardiovascular event as long as they are stable and that sauna is actually beneficial for this population [10,27].
Sauna appears to be safe for women who are pregnant [11], but you should talk to your doctor before implementing a sauna routine if you are pregnant. You should never consume alcohol before or during a sauna session as it has been associated with sudden death syndrome and overall just sounds like a terrible idea [25].
How hot should the sauna be?
A traditional Finnish dry sauna should be between 176-212℉ (80-100℃), with a humidity of around 10-20% to see the greatest health benefits [1].
How long should you stay in a sauna?
5-20 minutes is usually long enough to attain the health benefits of sauna [1].
How often should you use a sauna?
When it comes to saunas, more is better, at least when it comes to frequency.
While sauna bathing even just 1 time per week has been associated with a 65% decrease in dementia and Alzheimer’s disease [7], 2-3 times per week has been associated with a 25% decrease in cardiovascular mortality [4], a 28% decrease in respiratory disease [5], and a 24% decrease in all cause mortality [19], while sauna bathing 4-7 times per week has been associated with a 77% decrease in cardiovascular mortality [4], a 37% decrease in respiratory disease [5], and a 40% decrease in all cause mortality [19].
When should you sauna?
Common sauna etiquette
Sauna etiquette varies from country to country and even state to state, but there are a few common courtesies that go a long way in ensuring that everyone gets heated, but only in a good way.
1. Shower beforehand
While everyone quickly becomes a puddle of sweat in a sauna it’s important to wash off before entering to make sure you’re not tracking in any unnecessary dirt or germs.
2. Sit on a towel
Again, while everyone will inevitably have a pool of sweat around them in the end, nobody wants to sit in someone else’s sweat puddle, so sitting on a towel is the best course of action here.
3. Don’t manspread if it’s a tight space
While this one might sound like common sense, there are a whole host of people who take up both armrests on airplanes that could probably use a gentle reminder to make sure everyone has enough space to get their sweat on.
Summary
Sauna bathing once a week is good, 2-3 times a week is great, and 4-7 times a week is best for health and longevity. Research suggests that 5-20 minutes at a temperature between 176-212℉ (80-100℃) is great for your overall health. Sauna bathing has been shown to be safe and beneficial for most people, even those who have experienced a cardiac event, as long as they are stable. That being said, make sure to talk to your doctor before hitting the sauna.
Stay sweaty y’all,
John
P.S. In the interest of transparency and helping you the reader understand what information I’m citing from each study, I’ve included my notes in the reference section so that you can get a better idea of what exactly I’m citing from each study, as well as further details that I consider when citing a study but may not include in the main body of the article for the sake of concision.
[1] Cardiovascular and other health benefits of sauna bathing: a review of the evidence
80-100C
10-20% Humidity
5-20min
Benefits of sauna
-sauna helps decrease chance of respiratory disease (asthma, pneumonia, or chronic obstructive pulmonary disease)
-sauna has been associated with improvement in pain in musculoskeletal disorders like osteoarthritis, rheumatoid arthritis, and fibromyalgia
-sauna may help decrease headache intensity
-sauna is associated with better physical function, vitality, social functioning, and general health
-safe for people who have STABLE cardiovascular disease or had a myocardial infarction, or stable angina pectoris, or heart failure (and it’s actual good for them)
-UNSTABLE not safe
-don’t do contrast if you have CVD
–Sauna has beneficial effects on CVD independent of exercise
[2] Effects of Steam Inhalation on Nasal Mucociliary Clearance in Normal Individuals and Nasal Disease State
Steam helps clear mucus
[3] Far-infrared saunas for treatment of cardiovascular factors – summary of published evidence May help lower blood pressure May be a therapy for congestive heart failure
[4] Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a perspective cohort study
Sauna decreases chance of dying from cardiovascular disease
Sauna 2-3x per week = 25% decrease in risk of cardiovascular mortality
Sauna 4-7x per week = 77% decrease in risk of cardiovascular mortality
[5] Sauna bathing reduces the risk of respiratory diseases: a long-term prospective cohort study
2-3x/week sauna associated with a 28% decrease in respiratory disease
4+/week sauna associated with a 37% decrease in respiratory disease
[6] Sauna Bathing and Risk of Psychotic Disorders: A Prospective Cohort Study
–Frequent sauna bathing is associated with decreased risk of psychotic disorders in middle aged men
-Might be due to decreased HPA activity (high HPA activity is associated with psychosis)
-Sauna was 79 degrees C
[7] Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men
Sauna may help prevent Alzheimer’s and dementia
Prospective study – 2315 Finnish men 42-60 at baseline
1x sauna session per week = 65% decrease in Alzheimer’s and dementia
7x sauna session per week = 66% decrease in Alzheimer’s and dementia
[8] The Effects of Sauna bathing on lipid profile in young, physically active, male subjects
Sauna improves cholesterol levels
LDL decreased
Total cholesterol decreased
3×15 min with 2min in between saunas at 90 degrees C
[9] Changes in the lipid profile of blood serum in women taking sauna baths of varios duration
-Decreased LDL
-Decreased total cholesterol
-Increase in HDL
[10] Cardiovascular and other health benefits of sauna bathing: a review of the evidence
Duplicate, see reference [1]
[11] Health effects and risks of sauna bathing
May decrease pain
Sauna bathing is safe for people with heart conditions as long as they are stable
No reported adverse effects of bathing during pregnancy
[12] The sauna and rheumatic diseases
Sauna helps alleviate rheumatic pain and improves joint mobility in 50% of men
25% of women find it detrimental
[13] Efficacy of regular sauna bathing for chronic tension-type headache: a randomized controlled study
Regular sauna bathing decreased perceived headache intensity, no change in duration of headaches, improvements in sleep or depression between groups
[14] Growth Hormone – Doping in Sports: Biochemical Principles, Effects, and Analysis
Growth hormone increases lean body mass, decreases fat mass, improves VO2max, and maximal power output.
[15] Endocrine effects of repeated sauna bathing
Repeated sauna bathing (twice per day, 1hr each time (30min, 5 min cooling, 30min), for 7 days at 80 degrees C)
-decrease in cortisol and ACTH
-slight increase in catecholamines
-Growth hormone increased by 16x in males, 2.3x in females, but declined after the third day
-Prolactin levels increased by 2.3 for men
[16] Exposure Elevates Plasma Immunoreactive Growth Hormone – Releasing Hormone Levels in Man
Older 49-66 year old men did not see and elevation in GH from sauna
Younger men did see an increase in GH from sauna
[17] Effect of post-exercise sauna bathing on the endurance performance of competitive male runners
Sauna may increase endurance performance via an increase in blood volume
Small sample size, only 6 male distance runners
Sauna bathing increased time to exhaustion by 32% – it says that’s an enhancement of approximately 1.9% in an endurance time trial…I don’t understand what they mean by that or how they calculated that number.
-increase in plasma volume (7.1%) and in Red Blood Cells (3.5%) (Confidence interval includes 0 – so not significant)
Improvement in performance was likely via an increase in blood volume
[18] The effect of a single Finnish sauna bath after aerobic exercise on the oxidative status in healthy men
Sauna may aid in post workout recovery from oxidative stress – this was contrast bath though 10min at 90 C and then cold shower, repeat for 30 min total sauna time
Don’t love this study – all did the same protocol so Day 1 was normal rest after aerobic exercise, Day 2 was sauna after aerobic, how do we know it wasn’t the consecutive days of aerobic exercise that increased the endogenous antioxidants?
Sauna significantly (by 8.1% and 8.9% respectively) increased endogenous antioxidants glutathione peroxidase and superoxide dismutase and catalase
Sauna decreased oxidative stress
[19] Association between sauna bathing and fatal cardiovascular and all-cause mortality events
24% decrease in all cause mortality in 2-3x sauna group
40% decrease in all cause mortality in 4-7x sauna group (Table 2)
All cause mortality inversely related to frequency but not duration of sauna bathing
[20] Regulation of heat shock transcription factors and their roles in physiology and disease
Heat Shock Transcription Factors (HSFs) improve ability to withstand stress, help protect from protein misfolding, inflammation, and detrimental environmental exposures
-”HSFs activate and repress genes that modulate metabolism, survival and proliferation in a context-dependent manner”
-HSF1 protects cells from proteotoxicity and cell death. This function is impaired in neurodegenerative diseases
-This ability to protect from cell death is exploited by cancer
[21] HSF-1 mediated cytoskeletal integrity determines thermotolerance and life span
HSF-1 plays a prominent role in cytoskeletal integrity which may have beneficial effects on stress and aging (this study was done in worms)
[22] Stress (Heat) Shock Proteins – Chaperones in Cardiovascular Biology and Disease
GREAT Review of Heat Shock Proteins
Heat shock proteins are activated when 5 degrees celsius above normal growth temperature
Help protect against negative effects of hypoxia and ischemia
Heat and ischemia damage the cytoskeleton, also cause loss of mitochondria
HSPs decrease with aging in the (rodent) myocardium
[23] The effect of modifiable lifestyle factors on semen quality
1,311 participants – regular sauna use was linked with male infertility but more research is needed
[24] Seminal and molecular evidence that sauna exposure affects human spermatogenesis
Strong decrease in sperm count and motility (P<0.001) after using sauna
2x15min per week 80-90 C
Only 10 subjects though
Somewhat reversed by 3 month mark, completely reversed by 6 month mark
[25] Benefits and risks of sauna bathing (2001)
Sauna is unlikely to cause infertility
Alcohol consumption during sauna bathing increases the risk of hypotension, arrhythmia, and sudden death
[26] Testicular Heat Stress and Sperm Quality
Heat can damage sperm DNA, decrease motility and sperm count.
Sauna, warm baths, cycling, and laptop use can increase scrotal temperatures and potentially decrease sperm count.
[27] Repeated sauna treatment improves vascular endothelial and cardiac function in patients with chronic heart failure
Sauna improves clinical symptoms of people with Chronic Heart Failure
[28] Recovery from sauna bathing favorably modulates cardiac autonomic nervous system
HRV acutely increases in cooling off period post sauna
2 Responses
This is great! I feel like I have listened to so many podcasts go on and on about Sauna’s, but the volume of information has felt overwhelming. This actually makes me feel grounded in the research that’s out there. I never thought I would be a sauna girl, but things change!
Hi Tess,
We’re so glad you like the article!
Enjoy the heat,
John