Sauna how long benefits

Research has shown that a deeper, more relaxed sleep can result from sauna use. In addition to the release of endorphins, body temperatures, that become elevated in the late evening , fall at bedtime. This slow, relaxing decline in endorphins is key in facilitating sleep. Numerous sauna bathers worldwide recall the deep sleep experiences that they feel after bathing in the calming heat of a sauna.

German sauna medical research shows that saunas were able to significantly reduce the incidences of colds and influenza amongst participants. As the body is exposed to the heat of a sauna and steam in the case of traditional saunas , it produces white blood cells more rapidly, which in turn helps to fight illnesses and helps to kill viruses.

In addition, saunas can relieve the uncomfortable symptoms of sinus congestion from colds or allergies - especially when used with steam tip: add eucalyptus to the water for added benefit and overall enjoyment. The steam vapor action helps to clear up unwanted congestion and is a wonderful aspect of the Finnish sauna experience. When the body begins to produce sweat via deep sweating, the skin is then cleansed and dead skin cells are replaced - keeping your skin in good working condition.

Sweating rinses bacteria out of the epidermal layer and sweat ducts. Cleansing of the pores has been shown to improve the capillary circulation, while giving the skin a softer-looking quality. Outlandish claims are often made by some sauna sellers to promote saunas as an end-all weight loss tool. While some individuals may experience high amounts of calorie burn at first - particularly those individuals in poor shape to begin with - over the long term, saunas are simply treated as one of many tools in our arsenal when it comes to burning additional calories.

The sweating process itself requires a notable amount of energy. That energy is derived from the conversion of fat and carbohydrates in a bodily process that burns up calories.

According to U. Army medical research Ward Dean, M. As heart activity increases and as these processes demand more oxygen, the body begins to convert more calories into usable energy. Forty clinical studies involving a total of participants met the inclusion criteria.

Reported outcome measures were heterogeneous with most studies reporting beneficial health effects. Regular dry sauna bathing has potential health benefits. More data of higher quality is needed on the frequency and extent of adverse side effects.

Further study is also needed to determine the optimal frequency and duration of distinct types of sauna bathing for targeted health effects and the specific clinical populations who are most likely to benefit.

Sauna bathing is a form of whole-body thermotherapy that has been used in various forms radiant heat, sweat lodges, etc. Modern day sauna use includes traditional Finnish-style sauna, along with Turkish-style Hammam, Russian Banya, and other cultural variations, which can be distinguished by the style of construction, source of heating, and level of humidity. In the past decade, infrared sauna cabins have become increasingly popular.

Sauna bathing is inexpensive and widely accessible with Finnish-style saunas more often used in family, group, and public settings and infrared saunas more commonly built and marketed for individual use.

Public sauna facilities can be located within exercise facilities and the relationship between saunas and exercise, which may include synergistic hormetic responses, is an area of active research [ 3 — 8 ]. The use of private saunas, especially involving infrared saunas, is also increasing and saunas are used for physical therapy in massage clinics, health spas, beauty salons, and domestic homes. This trend is capitalising on the call for additional lifestyle interventions to enhance health and wellness particularly in populations that have difficulty exercising e.

Facilities offering sauna bathing often claim health benefits that include detoxification, increased metabolism, weight loss, increased blood circulation, pain reduction, antiaging, skin rejuvenation, improved cardiovascular function, improved immune function, improved sleep, stress management, and relaxation. However, rigorous medical evidence to support these claims is scant and incomplete, as emphasized in a recent multidisciplinary review of sauna studies [ 10 ].

There is considerable evidence to suggest that sauna bathing can induce profound physiological effects [ 4 , 11 — 17 ]. Intense short-term heat exposure elevates skin temperature and core body temperature and activates thermoregulatory pathways via the hypothalamus [ 18 ] and CNS central nervous system leading to activation of the autonomic nervous system. The activation of the sympathetic nervous system, hypothalamus-pituitary-adrenal hormonal axis, and the renin-angiotensin-aldosterone system leads to well-documented cardiovascular effects with increased heart rate, skin blood flow, cardiac output, and sweating [ 1 , 11 ].

The resultant sweat evaporates from the skin surface and produces cooling that facilitates temperature homeostasis. In essence, sauna therapy capitalises on the thermoregulatory trait of homeothermy, the physiological capability of mammals and birds to maintain a relatively constant core body temperature with minimal deviation from a set point [ 19 ].

It is currently unclear whether steam saunas invoke the same degree of physiological responses as dry saunas [ 20 ], as the higher humidity results in water condensation on the skin and reduced evaporation of sweat [ 21 ]. On a cellular level, acute whole-body thermotherapy both wet and dry forms induces discrete metabolic changes that include production of heat shock proteins, reduction of reactive oxygenated species, reduced oxidative stress and inflammation pathway activities, increased NO nitric oxide bioavailability, increased insulin sensitivity, and alterations in various endothelial-dependent vasodilatation metabolic pathways [ 22 ].

It has been suggested that heat stress induces adaptive hormesis mechanisms similar to exercise, and there are reports of cellular effects induced by whole-body hyperthermia in conjunction with oncology-related interventions i. While a small number of reviews of sauna bathing and health have been conducted in the past [ 1 , 2 , 28 — 30 ], as far as we know, this is the first systematic review of sauna and health to include both Finnish and infrared saunas.

Furthermore, this review only considers effects related to regular, multiple sessions of sauna activity rather than single sauna sessions, to better reflect the use of sauna bathing as a regular lifestyle intervention.

PRISMA guidelines for conducting systematic reviews were followed, including the use of validated tools to assess the risk of bias in randomized controlled trials [ 70 — 72 ]. Studies of humans undergoing repeated dry sauna bathing that reported on health measures were included in the review. Studies were included for initial review if they were published in English language from January onwards and involved research in humans undergoing repeated dry sauna sessions with at least one reported health outcome.

Studies of partial body heating were excluded since proposed mechanisms of action may or may not be the same as whole-body heating. Studies reporting primarily animal-based, nonhuman findings were excluded given the recognized differences in end-organ skin structure and responses sweating mechanisms between animals and humans. Search dates were chosen to focus on updated findings reflecting advancing technology in both diagnostics and physiological monitoring to build upon the foundational literature of prior nonsystematic clinical reviews of sauna activity published in the early s.

Abstracts of initially identified studies were screened by investigator JH and then the complete full-text articles of potentially eligible studies were carefully screened by both investigators JH and MC for research design, population descriptive data, timing and physical details of dry sauna intervention, outcome measures, key results, and adverse effects.

Discrepancies regarding inclusion of studies or data extraction were discussed until consensus was reached. Included randomized controlled trials RCTs were assessed for risk of bias according to the Cochrane Collaboration's tool for assessing bias and calculated Jadad et al. Domains of bias assessed were selection bias by looking for random sequence generation and allocation concealment , performance bias by published mention of blinding of participants and personnel , detection bias by documented attempts to blind outcome assessment , attrition bias by evaluating for incomplete outcome data , reporting bias by any indication of selective reporting of outcomes , and other bias e.

Any discrepancies were discussed until consensus was reached. Figure 1 summarises the screening and assessment strategies used with the search results. Of the nonduplicate citations initially identified, were excluded after a review of the abstracts. After retrieving full-text articles and applying the same exclusion criteria as discussed above along with excluding review articles, case reports, and letters to the editor, 69 independent human studies involving dry sauna interventions were identified for further analysis.

In the data extraction step, one study was excluded since it was essentially a case series with two patients, mistakenly identified as an interventional trial conducted by a key author [ 73 ].

Another 28 studies were excluded due to the intervention being only a single session of sauna and not repeated sauna therapy, which is the stated focus of this review.

A total of 40 studies remained for inclusion in this systematic review. Of the forty studies, 13 were randomized controlled trials RCTs , 6 were trials with nonrandomized control groups and 2 were prospective cohort studies.

The remainder of studies were single-group or multigroup interventional trials without a control group or retrospective studies. The following three levels of evidence were used to help stratify the quality of the studies.

Level III: retrospective comparative study; case-control study; pilot study. Many studies were relatively small, with limited number of participants, and a limited number of randomized studies were available for review. Nine of these 13 RCTs enrolled fewer than 50 participants. Table 8 summarises the assessments of the RCTs for overall risk of several types of bias. The follow-up time of many of the studies was relatively short, in the order of weeks to months, thereby possibly compromising detectability and reporting of long-term health effects over years.

The reviewed studies included a total of participants living in 12 different countries. Over half of the studies 22 of 40 originated in Japan. Most studies had small sample sizes with over half 21 of 40 studies involving 30 or less participants.

The studies involved a range of healthy and disease populations with 6 studies of healthy individuals, 19 studies of people diagnosed with cardiovascular disease CVD or increased risk for CVD i.

Eleven studies investigated the use of Finnish saunas and 25 studies utilised infrared sauna interventions. The remainder 4 studies used other forms of dry sauna Thai-style or mixed. Sauna sessions varied from 5 minutes to 20 minutes in single or multiple sessions totaling 30 minutes—4 hours daily, once to several times each week over study durations that ranged from 3 days to 5 months. The cohort studies followed frequent infrared sauna bathers for 5 years and frequent male Finnish sauna bathers for over 20 years.

Of the 25 studies involving infrared sauna, all used far-infrared types except Ross and Sternquist , which employed a full-spectrum infrared sauna as part of a detoxification protocol for policemen [ 69 ].

All of the sauna interventions were conducted in supervised settings i. Some studies focused solely on measuring subjective quality of life and symptom scoring surrounding sauna activity such as SF item short form health survey ; FASE Foundation for Advancements in Science and Education item survey of symptoms and sleep, CMI Cornell Medical Index survey of somatic complaints; VAS visual analogue scales for hunger, relaxation, and specific types of pain i.

Other interventional studies focused on obtaining objective measures related to sauna activity. Studies involving patients with increased cardiovascular risk or studies of healthy patients with aims of detecting changes in cardiovascular risk with sauna activity used some of the same physiological parameters mentioned above as well as serum lipid profiles total cholesterol, LDL, HDL, and triglycerides , fasting plasma glucose levels, serum levels of uric acid potential marker of insulin resistance and metabolic syndrome , plasma levels of ghrelin, serum levels of leptin, plasma levels of Hb hemoglobin and HCT haematocrit , and urinary prostaglandin levels [ 37 , 47 , 49 , 63 , 66 , 67 ].

Other interventional studies employed a combination of subjective and objective measures. Shinsato et al. Kikuchi et al. Oosterveld et al. Two studies investigated the effects of repeated sauna sessions on patients with peripheral arterial disease.

Another randomized controlled trial examined the effects of repeated sauna therapy on 24 ischemic heart disease subjects with chronic total occlusion of coronary arteries detected on coronary angiogram who had failed or rejected attempts at percutaneous coronary intervention or who had vessels deemed unsuitable for operative interventions.

The two largest studies of this review which prospectively followed men in Finland over A Japanese single-group study of 44 patients diagnosed with fibromyalgia with or without another rheumatological disorder i.

Soejima et al. Amano et al. Two randomized controlled trials investigated the subjective effects of repeated sauna on chronic pain disorders. Two studies focused on the effects of infrared sauna on patients diagnosed with COPD chronic obstructive pulmonary disease. No other changes in spirometry parameters or 6-minute walk test distances were detected between the two groups [ 59 ].

The researchers also examined HRV heart rate variability parameters but detected no significant difference between the sauna and control groups [ 57 ]. Two small noncontrolled interventional trials studied the physiological effects of repeat sauna in athletes. The researchers also noted postsauna increases in mean venous pH by 0. Two small uncontrolled, single-gender studies reported reduced total cholesterol levels 4. The same research group of both studies reported earlier findings of significant increases in heart rate, systolic blood pressure, growth hormone, adrenocorticotropic hormone, and cortisol levels along with significant decreases in diastolic blood pressure and plasma volumes after single and repeated sauna sessions in 20 women after 2 weeks of either min sauna sessions or min sauna sessions [ 63 , 65 ].

Reductions in total and LDL cholesterol levels along with increased HDL high density lipoprotein cholesterol levels were reported in the min sauna group. Skin surface pH was generally measured to be lower in the regular sauna group but similar scales of pH elevation were recorded for both groups during and after sauna activity [ 64 ].

Populations burdened with toxicants were the subject of two studies. Both entailed multimodal therapies with sauna as a prominent but not sole intervention and both demonstrated improved self-assessed quality of life measures [ 68 , 69 ]. One longitudinal time-course study examined the effects of Finnish sauna activity on male sperm and fertility measures in 10 healthy men. However, all specified changes reverted back to normal 6 months after ceasing sauna activity and no significant changes in plasma sex hormones from baseline were detected directly after sauna or after 3 or 6 months [ 27 ].

Of the 40 included studies, only eight reported any adverse symptoms from sauna bathing. Six studies recorded adverse effects graded as mild, meaning symptoms of complaint were noted which did not alter the study protocol or incur dropouts to the study.

Mild heat discomfort was the major complaint [ 53 , 61 , 69 ]. Pach et al. Two studies recorded moderate adverse effects, defined as symptom complaints that led to dropout of study participants or led to changes in study protocols. None of the included studies reported severe adverse effects involving the need for emergency medical services. The findings of this review suggest frequent dry sauna bathing improves a variety of subjective and objective health parameters and that frequent Finnish sauna bathing is associated with improved outcomes such as reduced overall mortality and reduced incidence of cardiovascular events and dementia, at least in men [ 38 , 39 ].

The most established clinical benefits of sauna bathing are associated with cardiovascular disease, yet there is also evidence to suggest that saunas, either Finnish-style or infrared, may benefit people with rheumatic diseases such as fibromyalgia, rheumatoid arthritis, and ankylosing spondylitis, as well as patients with chronic fatigue and pain syndromes, chronic obstructive pulmonary disease, and allergic rhinitis.

Sauna bathing may also improve exercise performance in athletes, skin moisture barrier properties, and quality of life and is not associated with serious adverse events. There is not yet enough evidence to distinguish any particular health differences between repeat Finnish-style and repeat infrared sauna bathing.

Cardiovascular disease has clearly been a focus for sauna researchers since despite Finnish-style sauna being considered by some in the past as a contraindication for patients with CHF and other cardiovascular diseases, most likely because of perceived intolerance to the high temperatures [ 1 ].

Nearly half 19 of 40 of the studies included in this review involved populations who had active cardiovascular disease or increased risk for cardiovascular disease, and all these studies demonstrated beneficial health effects. Seven of these 19 studies were randomized controlled trials RCTs , with only one of them meeting the Cochrane criteria for an acceptably low risk of bias. These Waon therapy studies used similar outcome measures and mostly involved hospitalised patients, which might reflect some differences in health care systems and thresholds for hospitalisation.

The use of primarily hospitalised patients in these studies also brings up issues of how applicable the findings may or may not be to outpatient populations. Despite differences in sauna types, temperature, frequency, and duration of interventions, the far-infrared sauna studies involving cardiovascular disease and congestive heart failure patients suggest favourable outcomes that reinforce earlier findings of interventional Finnish sauna studies and cardiovascular disease [ 75 — 79 ].

This suggests that heat stress, whether induced by infrared or Finnish-style sauna, causes significant sweating that is likely to lead to hormetic adaptation and beneficial cardiovascular and metabolic effects. Nevertheless, these findings point to the need for further study and serious consideration given to sauna bathing to address the ever-increasing individual, societal, and financial burdens of cardiovascular disease as well as dementia-related conditions in aging populations.

Several mechanisms of action have been proposed for the health effects of frequent sauna bathing. Together, these findings support complex multipathway end-organ effects on the central and autonomic nervous system, the peripheral vascular endothelium, and the hypothalamus-pituitary-adrenal axis, as well as on the kidneys and the liver that are continuing to be documented [ 1 , 11 , 28 , 81 ].

The complexity of how sauna bathing may influence cardiovascular risk factors is suggested by the report of beneficial effects on total cholesterol and LDL low density lipoprotein cholesterol and conflicting results on HDL high density lipoprotein levels in healthy young men and women [ 63 , 66 , 67 ].

These findings, which need to be confirmed in larger studies with nonsauna control groups, may point to differences between Finnish and infrared saunas as they contrast with previous similarly sized, yet better controlled studies of infrared sauna bathing in populations at increased risk of cardiovascular disease [ 37 , 47 , 49 ].

These findings may also be compared to the metabolic effects of exercise in healthy populations which include improvements in both LDL and HDL lipid levels [ 82 ]. This is supported by newer, single-cell analysis methods that suggest sauna bathing increases generation of free radicals and reactive oxygenated species along with enhanced antioxidant activities via proposed nitric oxide- NO- dependent processes in blood [ 62 ] and upregulation of specific HSPs heat shock proteins and HSFs heat shock factors in semen [ 27 ].

The two studies in athletes further support sauna's involvement in hormetic stress responses with the findings of plasma volume expansion after 4 days of daily postexercise sauna bathing, followed by a trend back to presauna levels by days 7—10 in one study [ 61 ], along with mean postsauna increases in axillary body temperature of 2.

Improved adaptation to stress with regular sauna bathing may be further enhanced by excretion of toxicants through heavy sweating.

Many industrial toxicants including heavy metals, pesticides, and various petrochemicals may be excreted in sweat leading to an enhancement of metabolic pathways and processes that these toxic agents inhibit [ 83 ].

Sweat-induced excretion of toxic metals such as arsenic, cadmium, lead, and mercury has been reported with the rates of excretion matching or exceeding urinary routes [ 84 ]. There is also recent evidence that toxic chemicals and xenobiotics such as polybrominated diphenyl ether PBDE flame retardants, organochlorine pesticides, bisphenol-A BPA , and phthalates may be excreted via induced sweating at rates that exceed urinary excretion [ 85 — 88 ].

The importance of sweat in excretion pathways has been further documented by sweat-patch technology used to monitor illicit drug use and is based on dozens of studies of the pharmacodynamics and pharmacokinetics of amphetamine, cocaine, cannabis, opiates, and associated metabolites [ 89 , 90 ].

While sweat-induced detoxification certainly occurs, studies using sauna for detoxification purposes report more favourable findings with subjective rather than objective measures [ 68 , 69 ]. In addition to having profound physiological effects, sauna bathing is reported to have beneficial psychological effects that are reflected in the many reports of improved well-being, pain tolerance, and other self-assessed symptom-related scoring [ 34 , 36 , 43 , 45 , 46 , 50 — 56 , 58 , 60 , 68 , 69 ].

The psychological impact of sauna bathing may be due to a combination of factors that include release of endorphins and other opioid-like peptides such as dynorphins [ 81 , 92 ], forced mindfulness, psychological stress reduction, relaxation, improved sleep, time out from busy life schedules, placebo effects, and other aspects of individual psychological and social interactions that likely occur around frequent sauna activity. While it is difficult to distinguish between the different factors that produce positive psychological effects, such effects may enhance other physiological and metabolic benefits as they are likely to promote adherence to regular sauna activity.

The risk of death from saunas was examined in retrospective population studies of frequent sauna users in Sweden and Finland, with the annual death rate from saunas being reported as 0. Detailed comparative analysis of adverse effects between studies was limited by small sample sizes, heterogeneity of sauna types and study design many without control groups , and inconsistent reporting of adverse side effects within outcome measures. The highest intensity of adverse effects moderate levels of heat intolerance occurred in populations afflicted with chronic fatigue syndrome, chronic pain, rheumatoid arthritis, and ankylosing spondylitis.

The direct adverse effects of heat may also be responsible for the impairment of sperm counts, concentration, and motility and upregulation of heat-stress-related genes reported in the sperm of 10 healthy men after a 3-month course of Finnish-style sauna [ 27 ]. While these findings are based upon one identified study of only 10 men, the findings are consistent with some earlier research on the effects of genital heat stress on semen quality [ — ].

However, long-term…. If you're wondering what foods you should be including in your diet, look no further. We cover an A to Z of popular healthy food items.

The most healthful diet involves eating a variety of nutrient dense foods from all major food groups. Learn about healthful diets and tips here. Liver cleanses promise to rid the body of toxins and impurities, but are controversial because there is little science to support their use.

What are the benefits and risks of a sauna? Medically reviewed by Yamini Ranchod, Ph. What is a sauna? Health benefits Risks and precautions Far-infrared saunas Myths Saunas have been used for thousands of years and are still popular today. Share on Pinterest A sauna helps relax, and it may have other health benefits, too. Possible health benefits. Health risks and precautions. Far-infarared saunas: Do they work? Health myths. Exposure to air pollutants may amplify risk for depression in healthy individuals.

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Medically reviewed by Stacy Sampson, D. How can these popular foods benefit our health? Medically reviewed by Natalie Olsen, R. How to follow a healthful diet.

Do liver cleanses work? Evidence and risks. Medically reviewed by Debra Rose Wilson, Ph. And it worked amazingly for my mental performance. Nice summary article Dave.

Very easy to skim over and pick out benefits. Would be great to see the sources referenced though since you say these are all proven. Going through such blog posts are always have a great experience. Thanks for sharing the useful and informational stuff here with us. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. This site uses Akismet to reduce spam.

Learn how your comment data is processed. What is a Sauna? Different Types of Saunas Today, saunas are an everyday part of many cultures, from the Finnsh outdoor saunas to the Swedish batsu, the Korean jjimjilbangs, and Japanese sento. What Happens in the Body? Slow down Father Time aka: aging! Cell regeneration means you slow the aging process. Detoxify heavy metals and chemicals. Everyday exposure to potentially toxic heavy metals through a variety of sources means even the most health conscious people still have toxins in the body.