That might have an effect, but these studies are probably mostly selecting for people who can tolerate a hostile environment for longer, which are usually healthier. I find it unlikely that sauna alone explains the fantastic, almost miraculous hazard ratios that these studies report.
All of these studies are always performed by Finns (or SE / DK / NO + maybe Russia).
I'd love to see this (and other sauna studies) replicated by someone somewhere to the south or hotter climates in general (southern Europe, Africa, hotter parts of Asia and the Americas).
And also replicated with participants not used to high temperatures inside a typical Finnish sauna. As the study said such people are very difficult to find in Finland. But I wonder if a person who has never been to a real sauna would tolerate this study protocol (2*15 min at 73° Celsius) without any training.
Sauna and hot climates may sound counterintuitive, but it has been tested by most Finns that when you come out of a hot sauna any outside temperature feels cool.
I doubt they would replicate it or any of the magical effects of saunas. Lots of the sauna studies suffer from the same issue where people self-report sauna usage rather than being assigned randomly to a treatment group. In countries where saunas are readily accessible and most people are under the impression that the more you use sauna the healthier you are, the ones that use the sauna less are probably because they tolerate it far worse. And that's probably related with age, comorbidities, physical condition, etc.
Basically, the sauna studies are probably mostly discovering that "healthier people can stand sauna longer". In countries where most people don't stand sauna for more than a few minutes, that self-selection bias won't exist.
What about Japanese hot springs? ("onsen")
Those are typically around 40°C but could be up to 60°C. Because it is hot water and not hot air the temperature would be transferred differently to the body though, so I don't think the numeric temperature is directly comparable.
Onsen baths are taken all year round: including summers that get hotter than in Finland, but especially enjoyed in winter.
Yes. And if you can get it to 102F your body will produce heat shock proteins. Which are good for a whole bunch of reasons, but also can be very bad if you have any tumors, as it makes damaged cells more resistant to apoptosis.
Anecdotal evidence. But since I started doing sauna regularly (once a week) I started to get sick less. I’m talking colds or flues. And the ones I did catch were much milder. Even with sick family members around I’m not catching it as often.
I heard that we often get cold/flu/sore throat when we get too cold outside, because the inside of our orifices is kept at a certain temperature to kill those bacteria/viruses. When we get too cold, we are unable to kill them fast enough, and get overrun. Staying in 70-100°C air for prolonged time must also heatshock those parts of our bodies, so I guess we kinda sterilize it that way.
Also anecdotal evidence, I haven't been sick this whole past 12 months. Any change I made in the past 12 I could've contributed to this. Nothing particular comes to mind but there were lots of changes (e.g. work, home, diet). That's the issue.
You'd have to stop sauna for a while and see if it reverses to strengthen the anecdotal case I guess.
Sauna is the perfect activity to add to most people's everyday routine. It is 30-60 minutes of relaxation for the body and mind, which nicely fill in the slot between dinner and bedtime, instead of TV/Netflix or doom scrolling in the sofa.
Back in Eastern Europe I frequently visited public "sauna" with my parents. It included jumping into freezing water after three heat sessions and the only thing you feel is just tingling in your skin. During those years all my respiratory illnesses were very brief and never affected lower areas (like bronchitis). The very first year I've emigrated I've got pneumonia and needed antibiotics twice during the cold season. The doctor told me it's just different viruses and I didn't have immunity for those (which is ridiculous considering globalization and I wasn't in an isolated tribe before).
For my parents though I think it was net health negative as public sauna was always accompanied with a lot of alcohol.
The thing about sauna I love the most is rare moment of absolute clarity after hot/cold cycle. I rarely can think so clearly, even if it's only for ten minutes, than after putting my body to stress by sauna heat.
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[ 17.6 ms ] story [ 171 ms ] threadWoah, that seems like a lot for me. I can usually stand maybe 60ºC for like 10 maybe 15 min. I don't think I'd be able to stand 30 min under 73ºC.
or is that just an urban legend claim?
Makes me wonder how much of it is Sauna, vs just the luxury of having the time to go do nothing for ~30 minutes.
Sometimes posting on Hackernews.
It’s one of the high points of my day (the soak, not the posting).
This “I wonder” just screams lazy thinking.
I'd love to see this (and other sauna studies) replicated by someone somewhere to the south or hotter climates in general (southern Europe, Africa, hotter parts of Asia and the Americas).
The experiments where at 73°C which is a lot hotter than most gym/hotel/spa saunas I’ve been in outside Finland
Sauna and hot climates may sound counterintuitive, but it has been tested by most Finns that when you come out of a hot sauna any outside temperature feels cool.
Basically, the sauna studies are probably mostly discovering that "healthier people can stand sauna longer". In countries where most people don't stand sauna for more than a few minutes, that self-selection bias won't exist.
Onsen baths are taken all year round: including summers that get hotter than in Finland, but especially enjoyed in winter.
Saunas are a great leveller between humans all living the same experience yet feeling alone in doing so.
At least my 2c why I think its helping
You'd have to stop sauna for a while and see if it reverses to strengthen the anecdotal case I guess.
For my parents though I think it was net health negative as public sauna was always accompanied with a lot of alcohol.
Weirdly I never saw any explanation.