There is similar study that showed a positive correlation between longevity and sauna use. Dr. Rhonda Patrick made the following comments its defense which I have pasted below.
Most of the dismissing comments have a few common themes...
1.) They underestimate the prevalence of sauna use in Finnish culture, where the study was conducted. Finland has a population of around 5 million people, but has around 3 million saunas. Sauna access is ubiquitous and not strictly a marker for socioeconomic status.
2.) They disregard the fact that physical activity was adjusted for. In other words, sauna use wasn't simply correlated to overall physical activity in this case.
3.) They assume that because sauna use is correlated with longevity (after variables are adjusted for) that we should expect Finnish folk to live as long as the trees. In actual fact, while sauna use is probably a healthy habit... the Finnish have habits that undermine their health just like any other country.
4.) They forget about the evidence in lower organisms. In flies and worms heat stress (exposing them to a 30 min. heat chamber just one time) has been shown to boost lifespan by up to 15%. This effect was shown mediated by heat shock proteins (hsps), which are very robustly increased in humans during sauna use. I don't know for sure that the Finnish sauna longevity study has anything to do with an effect from HSPs... but it stands to reason! The fact that lifespan extension was demonstrated in two very different lower organisms also means that this effect is highly evolutionarily conserved.
5.) They also tend to forget that humans that have a gene variant in heat shock protein 70 that makes it active all the time have a significant increase chance of living to be a centenarian (at least 100 years old).
I recently attended a talk by Dr. Rhonda Patrick on the biohacker summit in Finland. It was extremely interesting.
Another finding that I remember about physical activity being accounted for is the fact that sauna itself contributes to heart fitness, since cardiac activity is increased during sauna. So effectively reducing prevalence of heart problems in people with no pre conditions.
I live in Finland, and I also need to point out that sauna is almost an holistic thing, contributing greatly both to you mental and physical well being.
Do you know if they tried to control for other "healthiness" variables? Someone that goes to the sauna 4-7 times a week might be a person that pays much more attention to their health. I know physical activity was adjusted for but how about lots of other factors like diet and supplements or even just being a person that listens to their body more? I'd need to see data like that before I would even consider causation for this sauna reduction in dementia effect.
Do people socialise whilst being in a sauna, or do they rather meditate? Does it differ per person or region? If meditate, has there been cross reference between people who meditate instead of sauna?
Another difficulty with this question (socialize or meditate?) is caused by the Finnish approach to socializing. Is sitting silently together meditating or socializing? Since Finns can only communicate by text message, this is a valid question.
Ok, ok, just kidding -- Finns can talk plenty! But seriously, in Finnish culture sitting silently together is a legitimate form of socializing, unlike some other cultures. Conversation need not be constant.
An interesting documentary to watch is Miesten Vuoro (released as Steam of Life in English, but literally translating to 'men's turn'). It explores sauna culture on one level, men's emotional lives on another level.
And as ptaipale says below, "In sauna one should be like one is in church" -- my terrible translation of a phrase about a certain traditional attitude toward sauna behavior.
Well, you'd probably talk a bit initially and if you actually had something to say, but the American expectation that there has to be a constant stream of smalltalk (or inane blather, from a Finnish POV) is notably missing.
There's a classic joke about this:
One day two friends, Jukka and Pekka, meet after a long time apart and they go to a sauna in the woods. They drink vodka in silence for a couple of hours. Then Jukka asks: “So Pekka, how have you been doing?” Pekka says nothing, and they continue drinking for another couple of hours. Eventually Jukka asks: “How's the family?”. At that point, Pekka stands up and shouts: “Did we come here to talk, or did we come here to drink?”
I experienced the opposite. When I was young I, European, went to the States and I was being asked 'how are you' in a grocery store. So I ended up answering this question quite seriously until my American friend bumped me to explain we should move on. Obviously, there's only one correct answer to that question: 'good, how are you?'
I consider it an extremely rude gesture, and not at all courtesy. If you're asking someone how they are, you should do that genuinely, or not at all. While I fully understand how it is being courteous there are different ways to be courteous which don't include asking questions you don't really want answers to. IOW, I find it very fake.
Although I do experience it more here as well, thinking back I remember it occurring at work and in family. I tend to avoid using it.
Think of it as an opening. If there is really something you could relevantly discuss with that person, you have the opening, but normally it simply means the person is indicating some regard. To turn it around, it would be "extremely rude" of you to take everyone's time in going into details if there were no real reason to do so.
Yep, I eventually figured out its an opening, and I did learn to not answer the question. Nonetheless it is still rather odd to me given all the chit-chat Americans tend to have. It just seems inefficient to me, and it has too much potential for awkwardness. Hence I still remain of the opinion "if you don't want to hear an honest answer to a question; don't ask that question." akin to "doctor, it hurts when I do that; then don't do that."
I sortof feel the same on 'have a good one' except here this does not hurt anyone, and it does not cause misconception. It is merely ending on a positive note. With that being said, a better way of introducing is "hello, pleased to meet you" since it shows dignity, or just "hello, good morning" which is more neutral. All of these are kind and small gestures but not overly or in the sense of inviting too much chit-chat, or invitations to doors which ought to remain closed.
Anyway, no matter how much I dislike it, it won't change. At the same time I don't have to put myself on that level.
Socialising and meditation differs per person, not really by region in Finland.
Mostly the sauna is a family thing (yes, the whole kernel family of parents and small children may go together to their own sauna, everyone's naked, until the children are close to puberty and men and women of family go separately; public saunas such as those in swimming halls or the traditional public washing facilities are strictly gender-segregated.)
Sauna is perhaps a bit more of a social happening than meditation, although there are some clear aspects of meditation as well. As of old, sauna is a "holy" place; you're not supposed to yell, as the house-elves would not like it. In traditional farms, sauna was were babies were born, and where the dead were washed, so it's a bit of a place of reverence. And it used to be the cleanest and often warmest part of the household.
Then again all of my friends go to Sauna together, men and women, naked. There are some famous public saunas where you can do this, especially the now famous Sompasauna in Helsinki.
In Netherland all saunas tend to have men and women together, with rare exceptions. But saunas are much less common and less part of normal every day life than in Finland.
Mixed-gender saunas are pretty common if not the norm in Germany. At least all saunas I've been to were mixed-gender. Often they'll have one dedicated women-only day per week.
In the one I use here in MA (we call it a steam room- is it the same?) people are talking in what I think is Russian. I meditate. I also wear shorts, but many are naked.
Edit: It Looks like a sauna is dry heat, a steam room is obviously moist heat. The sauna is typically kept hotter- 160-200 deg F, while the steam room is usually 110-115 deg F.
Finnish sauna is not dry, the idea is to generate the steam (called löyly in Finnish) after you go in by throwing water on the hot rocks.
Best saunas are quite moist and not too hot, but the amount of moisture in air is controlled by the bathers. Sometimes this ends up in a competition (who can stand the wettest steam) but that's actually slightly bad manners.
For perfect results, I add a little beer to the water I throw on rocks (this is a matter of taste, some say that's not proper; in any case, things like menthol or eucalyptus don't really belong in Finnish sauna steam).
As to the positive health impacts, I'm completely agnostic. Or perhaps I think that it's more that healthy people can go often to sauna, not that going often would make you healthier.
Relative to "steam rooms" like Turkish bath a Finnish sauna is rather dry (relative humidity under 50%). Keeping the humidity in check is how the 80-100 °C temperature can be bearable in the first place.
Yes. Finnish spas and some swimming halls have a "steam sauna" which is lower temperature and very steamy, more like the Turkish bath, but still with wooden multi-level benches.
Any sauna is still very dry compared to a real steam bath. You would be boiled alive if a steam bath operated at sauna temperatures.
In Dutch saunas (many of which have a sauna room called "Finnish sauna", which tend to be the hottest and driest of all), löyly is not standard, but only done in one sauna room at specific times, and controlled by the sauna personnel. (Dutch saunas tend to be commercially exploited complexes with multiple types of sauna, a steam room, masseurs, etc.) The sudden increase in moisture does help make you sweat more, and a lot of people appreciate that (but not everybody). And it's definitely often with eucalyptus or other fancy oils.
in the Russian sauna (banya) even if you arrive to banya alone it's common to pair up with another person so that they can strike each other with banny venik--tree branches tied together in a bundle, white birch is probably the most common in Belarus. Particularly if you know well the other person (and know this is their preference) the striking can be quite vigorous. I suppose i would consider this both a form of socializing and meditation.
does anyone know if there is a temperature threshold for inclusion in the study? Saunas in the United States (only been in a few, like at the 24-hour fitness club) are, to me, tepid--feels like i'm in a sauna in which someone put out the fire several hours ago.
Russian saunas are are much, much hotter and i rarely see foreigners in them which suggests they are too hot for their tastes (though probably not for Turks or Finns). Saunas in villages or small cities in Russia and Belarus, which tend to adhere more to traditional recipes, are so hot (a little above 90 C, i've always been told is what they aim for) i can't tolerate them for more than a few minutes (and even the locals usually wear felt beanies while in there).
> This effect was shown mediated by heat shock proteins (hsps), which are very robustly increased in humans during sauna use.
Are they specifically heat related or any temperature stress might do?
I've been using cold water exclusively year round for last few years with occasional show/ice baths in winter time. I'm wondering if I'm missing something by avoiding warm water/saunas.
Heat shock proteins are really a response to abnormal protein folding (generally speaking) and are found upregulated in a number of stress response scenarios; including cold, heat, and oxidative stress
Re oxidative stress, can you give practical examples of how this is achieved for a person, what physical action creates it? https://en.m.wikipedia.org/wiki/Oxidative_stress suggests it's associated with lots of great harms - brain diseases, heart disease, etc.. How does that pair with longevity in practice?
>In flies and worms heat stress (exposing them to a 30 min. heat chamber just one time) has been shown to boost lifespan by up to 15%.
Does that mean one can have the similar effects by sitting close to a heat source for half an hour some, without the full cost (or exact technique) of being into a sauna?
Sitting next to the stove won't get the air round you to 70-80C, nor will you have the periodic steam that you get by pouring water onto the kiuas (sauna stove).
As a Finnish person this question makes no sense. Everybody goes to the sauna. The young, old, babies, the sick as well. I go to the sauna even with fever as it feels good with the chills.
It's tough to go to the sauna in the USA because it's rare that health clubs/gyms have them. Particularly since the advent of "box" type gyms that imitate Crossfit.
Archimedes Banya (www.banyasf.com/) is my favorite. They have a real Finnish sauna that gets up to 100 C (or over) along with a pool for cooling off that is less than 10 C. They also have two Russian baths and a Turkish bath (steam room). To get that real Finnish/Russian experience, you can even bring your own alcohol. Clothing is optional on one half and required on the other.
There are others in SF, but I haven't been to them.
I wonder if taking a hot bath can have the same effect. I've been taking them more frequently recently and I've definitely noticed that my heart rate goes up (and that I smell a bit different than after taking a shower, presumably because I'm sweating more). I've been debating whether or not it's actually a healthy thing to be doing, but it's definitely relaxing and makes you fall asleep faster at night as it's getting colder in the winter.
I wonder if the frequency of going to the Sauna was tied to the frequency of going to gym to workout? Here in Seattle that is basically the only place you can go to find a sauna.
The study was in Finland, where the sauna to population ratio is around 1:2. Also, the study claims to have adjusted for resting heart rate, which is a reasonable proxy for cardiovascular fitness:
In analysis adjusted for age, alcohol consumption, body mass index, systolic blood pressure, smoking status, Type 2 diabetes, previous myocardial infarction, resting heart rate and serum low-density lipoprotein cholesterol, compared with men with only 1 sauna bathing session per week, the HR for dementia was 0.78 (95% CI: 0.57–1.06) for 2–3 sauna bathing sessions per week and 0.34 (95% CI: 0.16–0.71) for 4–7 sauna bathing sessions per week. The corresponding HRs for Alzheimer's disease were 0.80 (95% CI: 0.53–1.20) and 0.35 (95% CI: 0.14–0.90).
Even in apartment buildings in Finland, each apartment is assigned sauna hours in the building's sauna. Sauna is truly a standard part of basic hygiene in Finland for most people. Living in a house/apartment without a sauna would truly be like living in a house/apartment with only a bathtub and no shower in the US. Sauna for many people is part of the evening bath/shower routine, not connected with workouts or other activities.
There is a sauna in nearly every house in Finland, and if not, then municipal swimming halls offer an affordable alternative which everyone can afford. No need to join it with heavy exercise. Also, going to a sauna does not signal a socioeconomic status.
It's amazing if Finland has solved poverty to the level that every household can afford to set aside the space for a sauna and costs of running it.
In the UK heat poverty is a widespread problem due to the costs of heating fuels. Presumably saunas are being run from geothermal sources to make it cheap enough??
I'm assuming saunas are cupboard sized, is that accurate or are all these homes dedicating a full room of space?
The prevalence of saunas in Finland is mainly because it has been a part of the Finnish way of life for thousands of years, not an exotic luxury in the way it might be perceived in some other countries.
Municipal facilities (swimming halls with saunas etc) are charged, probably about 4 euros per visit, with discounts for students and elderly.
The saunas people have in their homes these days are typically electric. Electricity prices are roughly the same, perhaps a bit less than UK - an hour of sauna with 4kw stove would probably cost around 0.5 euros in electricity. Some apartment blocks have shared saunas you can book for free, some have small saunas in each apartment. In detached houses you typically get a bit larger saunas.
In general access to saunas is widely available for everyone regardless of socioeconomic status, and there is less economic inequality in general compared to the UK.
Heating is a separate topic but I'll reply briefly - majority of housing in Finland is heated with district heating, rather than individual gas boilers in each house, like in the UK.
As a result, heating tends to be cheaper for consumers compared to the UK. Also, Finnish housing tends to be much better insulated than housing in the UK (because of colder winters).
Outside cities, where population is sparse, people heat their houses with electricity/wood/oil/geothermal - with many new builds now opting for geothermal.
Just a note about district heating: it's not majority of all housing (market share somewhere around 45 %), but it is majority of new housing (around 60 %).
And saunas are heated with electricity in towns, although a few old public facilities still run on wood stoves, as well as private saunas of those who like the "pure" feeling (such as myself).
> In the UK heat poverty is a widespread problem due to the costs of heating fuels.
I would imagine that he cost of the heating fuels is pretty much the same all over Europe. I think the difference is that in the Nordic countries people seem to insulate their houses better, like using double or even triple glasses in windows to reduce heat waste.
Yes, triple glass has been the norm for decades. You of course don't open the windows during the winter, and ventilation is almost always mechanical so that it can include heat recovery from the outbound air flow, allowing further savings in heating cost and emissions.
I would imagine that he cost of the heating fuels is pretty much the same all over Europe.
UK has 3.16 million hectares of woodland[1], Finland has 23 million hectares[2] of forest. UK population is 65 million, Finland has 5 million. [Wikipedia]
With 7 times more trees potentially providing fuel for 1/13th as many people, shouldn't it work out noticably cheaper?
I do not know, but if wood (or biomass) was noticeably cheaper than fossil fuels, I would think there was no need for climate agreements and there would be a large industry shipping wood from Canada and Siberia to use as a fuel.
Wikipedia says "The wood stove sauna is the most common type of sauna [in Finland] outside of the city areas".
In the context of "It's amazing if Finland has solved poverty to the level that every household can afford to set aside the space for a sauna and costs of running it.", and rural areas tend to be poorer than city areas, discussing wood as fuel for said saunas seems relevant.
The UK and Finland have very similar GDP per capita, but the UK is far more right wing than the Nordic countries have traditionally been, and as a result have a far less well developed benefits system and far larger salary differences. It's not that the Nordic countries have no poverty, but certainly the proportion of people who are absolutely destitute is much, lower.
Couple that with the higher housing costs associated with far higher population density (16 per km^2 in Finland vs. 255 per km^2 in the UK) and it seems less weird.
> It's amazing if Finland has solved poverty to the level that every household can afford to set aside the space for a sauna and costs of running it.
If you live in an apartment building, not every unit has a sauna--there is one shared across several units. If you live in a detached house, having a small sauna doesn't take up much space, and since it's so small and only used for an hour a day (if that), it's cheap to heat.
> In the UK heat poverty is a widespread problem due to the costs of heating fuels.
Based on my experiences in the UK, it's not heating fuel costs that's the problem, it's the sheer ubiquity of poorly insulated and air-sealed brick (and in Scotland, stone) houses with leaky single-pane sash windows.
> Here in Seattle that is basically the only place you can go to find a sauna.
Since this crappy cold weather hit I've found myself going to the gym nonstop just to dip in the jacuzzi... I don't know why most apartments in the PNW seem to not have one, maybe people up here don't like to swim as much as people in warmer climates?
Possibly related to dilating capillaries? Seems like my lasting impression every time I go into a sauna is that I get completely flushed, and that generally feels good. Maybe it proxies some of the benefits of cardio exercise?
They also have the highest life expectancy in the world. It could delay the onset but these individuals might live long enough to still be affected by it.
This whole text is such a prime example of what's wrong with science reporting.
In the very first sentence a causal relationship is claimed ("Frequent sauna bathing can reduce the risk of dementia"). Yet the whole article doesn't live up to that claim, because it is very clear that the study purely relies on observational data and thus may very well just have found a confounder. However it doesn't even bother to mention or discuss that limitation.
And this comment is a prime example of what's wrong with internet comments on scientific research.
Usually all the basic concerns have been accounted for in the actual study.
Whether an article in the mainstream press conveys that or not, is not important, since the article is just supposed to give a summary of the findings.
It's seldom an issue of "those stupid PhDs and experts in their field, they didn't think of a confounder a random internet person can come up with in 5 seconds".
Whoever wants to delve in can read the actual reports.
And whoever wants to start the same practice (e.g. sauna here) would be foolish to do it based on one article anyway, they should consult with their doctor, and/or wait until a fuller consensus has been reached after several meta-studies (which can take decades).
The parent comment is a valid criticism of the quality of reporting, especially in the context of the overall standard right now.
Claiming a causal relationship is an incorrect summary if the study did not show this. This is a very serious problem. If the particular study did in fact show good evidence of causality, that's worth specific highlighting because it's not that common.
The parent is not saying they've thought of some obvious confounder that the study authors didn't. They've emphasized the importance of unknown unknowns and correlation vs causation.
Raising the standard of science journalism is a noble goal, if you ask me. In this case, the authors are not making as strong a claim as the summary does.
> Usually all the basic concerns have been accounted for in the actual study.
Often. Yes. But I often go try to find the original publications when a study interests me, and I have yet to, once, find one where the causal claims made in the reporting article are actually supported by the research. Often the original paper explicitly mentions the fact that the claimed causal relationship can't be inferred.
The claim here isn't that the science is bad. No one's saying the PhDs are stupid (there may be an argument there, but that's not what anyone here is saying). The complaint is that the science reporting is terrible.
And it is.
> And whoever wants to start the same practice (e.g. sauna here) would be foolish to do it based on one article anyway, they should consult with their doctor
You are suffering under a severe delusion if you think the average doctor has the interest or competence to provide useful advice on this sort of issue. The average doctor will not have read any relevant studies, and has no interest in being informed about them, and I can say with some confidence that having a medical degree does not give him a magical ability to judge the usefulness of a practice without consulting any evidence.
Science is great, but science reporting is terrible, and for that matter unreasoned faith in the academic establishment is anathema to real science.
That's far too optimistic. I can't find the full text of this dementia study, but the one where they concluded sauna improves cardiovascular health barely gives any thought to the idea that perhaps men with a worse subjective assessment of their health are more likely to find it unwise to go to sauna too frequently. (In the closing paragraph they do a disclaimer "It is possible that underlying diagnosed or undiagnosed diseases may affect saunabathing habits, but our subgroup analyses according to various clinical characteristics were consistent.")
THe summary is actually wrong or at least severely premature, if it doesn't tell you whether this was about correlation without any real proof or analysis of causation.
> Usually all the basic concerns have been accounted for in the actual study.
No. It's an observational study. If they'd account for the basic concerns they'd do an RCT. Yes, that's more work and takes longer.
> It's seldom an issue of "those stupid PhDs and experts in their field, they didn't think of a confounder a random internet person can come up with in 5 seconds".
No, you don't understand the problem. Confounders everyone can come up with can be controlled for (although it gets complicated the more you consider). But the major problem are unknown confounders. You can't control for things you don't know.
"Observational study" does not mean "bad science". There are good and bad observational studies, and without reading the paper, you can't know which one this is. Moreover, your assertion that only random trials can be controlled is just completely wrong - there are plenty of ways to do controlled studies on observational data. You're engaged in the scientific version of the middlebrow dismissal.
In health sciences, a lot of good work starts as well-controlled observational science. In fact, for a question like "does sauna use lead to a reduced risk of dementia over a human lifetime?", pretty much the only way you're ever getting the funding to do an "RCT" is to start with lots of observational evidence.
"Usually all the basic concerns have been accounted for in the actual study."
Fair enough ... but there could be simple and nuanced elements that they didn't or couldn't measure.
For example: maybe Sauna dwellers are far more socially active than others? Social interaction is maybe they driver of longevity, the sauna may simply be a part of that process.
Anyhow, just a crude example ... but I'd suggest it's very hard for researchers to rule out most such things.
I felt the same way. If the authors did more to control for additional variables, then it was not clear in this article and that is fairly critical in terms of assessing the validity of the article's claim.
I saw the headline and thought: This is the best news ever! I love saunas, but I don't even come close to once a week. It's a special treat for us that we do maybe once every few months. To do it daily or weekly, it needs to be part of your routine, and really close to home.
But if the Finns really sauna this much more often than anyone else, then there should also be a noticeable difference in dementia between Finnish people and anyone else.
Seems like you could do a great confirmation study with participants in Bikram / hot yoga where the temps are 105F for 90 mins with ~50% humidity.
I'm going to go out on a limb and say the sauna cohort and the Bikram cohort are two extremely different sets of individuals with lots of different behaviors, so if the same effect was found in regular Bikram yogis a lot of variables might be able to be eliminated.
Saunas are much warmer than that. Regular sauna temperature in Finland is around 60°C - 90°C (which is around 140-190°F). This is the air temperature at which pretty much everybody goes to the sauna here, including the young, the old and sometimes even the ill.
Fair enough to make the comparison perhaps a poor one. However I don't think that people do yoga in saunas, but rather remain seated, correct? The point I'm getting at is: isn't the question "what's the net rise in body temperature?" In hot yoga, the room isn't as hot as a sauna but you're exercising strenuously, so that the body becomes about as hot as you can safely heat a body, kinda like a sauna.
I live in the south and even though it gets hot and humid in the summer, it does not sound like it's hot enough to shock like this study proposes. I mostly enjoy the heat and humidity. When I lived out west in a much drier climate, my gym had a sauna that I used almost every day.
When I sauna, we usually like the sauna at about 180 degrees Fahrenheit, and that's usual for Finns. The heat difference is enough that even when it's 90-100 degrees F in the summer (and humid) where I live, it's nice to take a quick sauna as it makes the rest of the evening feel much cooler in comparison!
Possibly, definitely in terms of relaxation, but in terms of heat shock I don't think so - Saunas in Finland tend to be heated quite hot - usually 70–80 °C, sometimes more.
Installing one isn't too difficult - if you have a garden, you can get outside kits which are generally as simple to build as sheds, or indoors kits that you'd put in a bathroom - probably when doing renovation anyway. I recommend ones from Harvia - I bought a medium sized one (fits 4 people) for about £1600 in the UK, and it took me and a couple of guys less than a day to put up.
Here are some pics - I built it as a part of a loft conversion and ended up tiling the outside so it looks like a part of the bathroom. Normally these prefab kits look like a softwood cladded mini-room from both inside and outside
In Finland they have portable saunas that they take to camping sides. Typically this is heavy-duty or army tent with a hole at top for a pipe from a small oven from cast iron.
You can easily go to a sauna with temperatures exceeding 110° C. Hot as heck, but even kids do it.
The starting temperature of World Sauna Championships was 110° C, with water/steam added every 30 seconds. The competition ended up killing a person, tho.
I'm surprised that sweat doesn't start boiling at that temperature, or that the users don't get severely burned since I assume everything in the sauna is going to be around that temperature --- even 50C is enough to burn skin:
My sauna last night was 84 C, 183 F. I personally don't like much hotter. The higher the temperature, the more you have to modulate the steam that you produce by throwing water on the stove. At a lower temperature I like lots of steam, but at higher temperatures a lot of steam at once can be too much. Steam is controlled by the users on a moment-by-moment basis while temperature is controlled more slowly by the stove settings (which of course you can change).
The wood in the sauna does get hot: that's why you either sit on a piece of cloth (more popular these days) or put cool water on your seat to cool it down so your butt doesn't burn. However, wood in saunas is generally carefully selected as some varieties feel cooler than others (and you never want to use a wood that will produce sap drips for your benches! ouch!!). There are almost no metal components to touch in a sauna because those hurt -- some people use copper buckets for water but then you're filling it with cool water intermittently.
Take off metal necklaces and earrings before saunaing, in general. Don't know about piercings (someone else can say). You can cook/burn yourself in a sauna but that is usually related to drug and alcohol use (as in the famous World Sauna Championship death: https://www.theguardian.com/world/2010/aug/08/sauna-champion...)
Sweat evaporates in the dry air, and that cools your skin. A bit. The wooden benches tend to get too hot to touch, which is one of the reasons why you sit on a towel. Glasses, watches and other objects are left outside. (I'm not sure how big of an issue piercings are, actually. If they get too hot, take them out.)
Still air is a good insulator, it doesn't transfer heat to your skin very quickly. And skin has good cooling via blood circulation and evaporating sweat. These cooling mechanisms also transfer more heat as the temperature difference grows.
> You don't actually get in the water at 80°C right?
No, you get in the water below 10°C. The 80° (or 90°C, as I often see claimed on Finnish saunas in Netherland) is the air. Extremely dry air, where your sweat evaporates almost immediately. Until someone pours on the löyly.
Is it possible that those undertaking frequent sauna bathing have overall healthier life habits? They might exercise more, eat better and sleep better than those who do not
protects? thats not proven, this studies implies onlY correlation and it could still be very much a random result or there coulf be multiple factord not taken in consideration
I just did a little research into the benefits of sauna use. I found a Reuters article published in 2015 which said, "men who spent time in a sauna seven times a week were less likely to die of heart problems or to die at all" [0].
So good news everbody: If you use a sauna seven times a week, there's a chance you could become immortal.
Although the correlation may be due to a factor not accounted for, it is not overall health or welfare. As people already mentioned, sauna use is not exactly a luxury in Finland and people who use saunas commit to unhealthy behaviour too.
I do wonder if there was a confounding factor that they didn't successfully isolate. "General health" seems like an obvious one, but some other factor might be more subtle.
From the abstract: analysis [was] adjusted for age, alcohol consumption, body mass index, systolic blood pressure, smoking status, Type 2 diabetes, previous myocardial infarction, resting heart rate and serum low-density lipoprotein cholesterol [1]. Of course, that doesn't rule out all confounding factors.
Have you read the study, which is published in a peer-reviewed journal, before making this statement? If not, your comment doesn't add anything useful to the discussion.
Yes, my comment made a statement that added to the conversation. Maybe you missed it? I'll expand for you.
I have studied statistics, and I understand that correlation does not imply causation. However, if you're going to allege that a professional scientific statistician failed to even consider the most trivial and obvious of non-causative correlations, then you're being insulting.
And it's fine to insult scientists. They're not special snowflakes. Do it, if they have a track record of lies, or deceit, or carelessness, or stupidity. But be aware when you're doing it, and why. Don't just blithely say "Hey guys, have we considered the possibility that these scientists are either drooling idiots or evil liars?" That's uncharitable to an extreme.
And yes, I've read it. They are not, as OP suggested, drooling idiots or evil liars.
All this is concluding is that of recreational activities spending time in the sauna is less harmful than the likely alternative ways people would fill that time.
The study was done in Finland. There are estimated to be 2-3 million saunas for a population of 5.4 million. Majority of the population has access to a sauna at home. It is not a luxury.
From $1000 to $5000 depending on size, luxury, and how much you do yourself vs hire out. There are a few things you want to be knowledgeable about if you do it yourself: moisture barriers and management, what kinds of woods to choose and what not to choose both for durability and comfort, and some understanding of stoves & rocks especially if you're picking your own rocks -- some types of rocks are prone to exploding and that's unpleasant.
You can buy prefab kits (so the moisture barrier is built in and the benches are pre-assembled) from companies like Finnleo, or you can buy a stove alone from tons of places. Just make sure you're buying a stove that is truly meant for a sauna (throwing water/making steam) instead of a heater for an infrared room (different!).
The title clearly implies an assumed cause and effect relation, while the article itself doesn't even propose any mechanism for causation, only that there is a correlation. I consider this a form of clickbait (and bait-and-switch), therefore my snarky reply above.
I was trying to make a broader point about cause and effect misdirection in low-information study results such as this (Finland is unusual in its great school system... It is more usual to attend a sauna than not to.... unlike most of the rest of the world) but it came off as pretty ignorant sounding to a lot of people.
I race and you had better have a second sport to keep you in shape for sailing.
It's concentrated uncomfortable sitting around combined with the occasional panic. If you're buoy racing, it's on the rail, over the top and grind for 3-5 seconds and on the rail.
Most of the dismissing comments have a few common themes...
1.) They underestimate the prevalence of sauna use in Finnish culture, where the study was conducted. Finland has a population of around 5 million people, but has around 3 million saunas. Sauna access is ubiquitous and not strictly a marker for socioeconomic status.
2.) They disregard the fact that physical activity was adjusted for. In other words, sauna use wasn't simply correlated to overall physical activity in this case.
3.) They assume that because sauna use is correlated with longevity (after variables are adjusted for) that we should expect Finnish folk to live as long as the trees. In actual fact, while sauna use is probably a healthy habit... the Finnish have habits that undermine their health just like any other country.
4.) They forget about the evidence in lower organisms. In flies and worms heat stress (exposing them to a 30 min. heat chamber just one time) has been shown to boost lifespan by up to 15%. This effect was shown mediated by heat shock proteins (hsps), which are very robustly increased in humans during sauna use. I don't know for sure that the Finnish sauna longevity study has anything to do with an effect from HSPs... but it stands to reason! The fact that lifespan extension was demonstrated in two very different lower organisms also means that this effect is highly evolutionarily conserved.
5.) They also tend to forget that humans that have a gene variant in heat shock protein 70 that makes it active all the time have a significant increase chance of living to be a centenarian (at least 100 years old).
For those interested, here's the sauna longevity study in question... http://www.ncbi.nlm.nih.gov/pubmed/25705824