Comment by kyriakosel

I recently listened to a podcast about the benefits of sauna or deliberate heat exposure and the gist is that if you get your core temperature at about 39 degrees celsius your cardiovascular system is working comparably hard to light exercise.

My take is that your heart and lungs are working out, even if your body is not. Do you get the same benefits as going for a run or bike ride for a comparable amount of time? no, since your limbs don't get fit, but your heart and lungs do.

Since you mention the TV, it seems there's a big factor missing in both the article and the discussion here. Namely, that sauna time is for many people the only time they ever take to be in silence, without the countless distractions otherwise bombarding our nervous systems. I.e. it's basically a form of informal meditation, which is known to have a lot of benefic impacts on body and mind. So maybe skip the TV part?...

Agreed - one is muscular/metabolic demand, the other (sauna) is thermoregulation.

Agreed on the long-term effect too: doing a study on long term health is a completely different story

This feels like a false dichotomy. Even if sauna doesn't impact long term health in a way that can replace exercise, that doesn't mean that it doesn't improve health.

> That is this improves a marker for good health without improving health

There is a substantial body of existing research to peruse about the impact of regular sauna use on health outcomes, much of it from Finland given the prevalence of sauna usage there allowing for larger sample sizes. It's a body of evidence rather than one knock-out experimental design.

Zero shot you'd make it an hour in a proper sauna for an hour. People have this idea that saunas are always enjoyable. I sauna daily, and its nice up to a point. For me thats like 10-12mins in. From then on, its tough.

My current guess is that you get much or most of the benefits, but not all (by both value and number). If you look at the actual changes in the body during both of these activities, most are the same as exercise, but not all.

For example: body temp increases, heart rate increases, and we sweat. But the muscles aren't "engaged", consuming stuff (glycogen, etc.) while doing sauna.

There could also be sauna benefits that exercise does not impart, or is less likely to do so: sweating greater than exercise could lead to excess excretion of plastics, carcinogens, etc.

Running in mild/cold temps we do little sweating (unless long duration exercise), whereas every darn sauna at sufficiently high temps we are going to be sweating.

My take is probably too nuanced here, but the reality is that we don't know. People living in areas with longevity (blue zones), didn't really excercise (as in sports) or take multivitamins. For all we know, it might even come out that regular, gym-style excercise is even worse for longevity.

Nordic people tend to live a long life even though they historically didn't have access to fresh vegetables or fruit and brutal winters (and darkness) prohibited excercise.

ps. I'm not arguing that excercise is unhealthy, it's just that its contribution to eventual longevity, is currently unknown. Whereas anectodal evidence of saunas (being around longer than "excercise"), seems to work.

This question is dead from the beginning. Exercise is good for the heart, the muscles, metabolism. You do need muscle contractions above certain level of intensity and duration for this to happen.

I think that if you have one hour or more of free time and live in an area where you have easy access to a sauna, that would result in significant better health on it's own. Even if you choose to not use the sauna.

I looked into Saunas in detail sometime back as a replacement/complement to exercise. There is a lot of research out there which says Saunas are as beneficial - but at the end of it I reached a similar conclusion - exercise is just better understood, so no point experimenting when something can go wrong.

A sauna will do nothing for muscular-skeletal health.

I don’t think the TV in the sauna will have long term health outcomes.

I'm being slightly snarky, but good luck watching a TV if you're doing an intense/valuable sauna session.

When I'm in my dry sauna and really pushing myself with the heat and steam off the hot rocks, I basically have to mediate to stay in beyond 15 minutes because every part of my mind starts telling me to get out and cool down.

One hour in sauna? :O

Even more likely is those using saunas and tracking metrics with wearables are self-selected to be healthier/more active/etc. Correlation and causation...

If you're watching TV in a sauna you haven't turned the sauna on.

> You'll be much better off peeing.

Actually, the rate of blood filtration by kidney glomerulae is pretty constant and independent of the amount of urine in your bladder. Except if you overflow to the point of drowning your kidney of course.

Actually, this is why one shouldn't believe HN comments about medicine. The quality is this low.

This is simply laughable and very easily checked out. Here is one random study:

https://link.springer.com/article/10.1007/s00244-010-9611-5

> Many toxic elements appeared to be preferentially excreted through sweat

Here is another quick one

https://onlinelibrary.wiley.com/doi/full/10.1155/2012/184745

> Sweating deserves consideration for toxic element detoxification.

Its even observable directly - just go next to the heavy smoker during exercise.

While it might be less than dedicated organs, the skin is the largest organ by far.

Ofc, the topic is debated like every single thing in medicine, but calling it a myth is nonsence.

> What wearables were used? These devices don't usually have enough precision to reliably detect ~3bpm changes.

For large sample averages this doesn't really matter.

> Is the wearable accurate enough to be sure that 3bpm is not a measurement fluke

If the statistical tests show significance (and are valid), the answer to this question is yes. If you have enough data you can make strong conclusions even witwith imperfect hardware.

we agree - but thats not that simple :)

Due to lots of long distance running my rest heart rate is below 40. I am highly skeptical I would experience a 3bpm lower heart rate after sauna. Maybe this benefit applies after infrequent activity or less intense activity only.

As someone with access to both Japanese ofuro and sauna, they are quite different in some respects. And similar in others. One thing which a sauna could do for me when the ofuro could not, was to fix a problem I had with coughing. Something which plauged me for a long time, and which the doctors couldn't find any reason for, but I had such painful daily coughs that it really bothered me. Couldn't sleep on my back either. Then I noticed that if I used the sauna daily, and carefully breathed hot air, the symptoms lessened. And after going for the daily sauna regime (instead of occasionally) for some time, the coughing problem I had for years finally disappeared. The hot baths did nothing for this (but was good for other things, e.g. muscle pains. And essential for being able to sleep at cold winter nights in non-insulated Japanese homes.. heating up the body with a very long very hot bath does wonders)

Dr. Rhonda Patrick has been beating the drum for saunas for a long time, and she's reported that a hot tub can be equivalent or better: https://x.com/foundmyfitness/status/1955294334535995850?lang...

You are replying to a comment that said they log and control for time of activity.

If your resting heart rate is lower without any drugs, it indicates that your heart can cause sufficient oxygen to be delivered to your organs with less effort than if it were higher. That can be caused by a variety of things (including stroke volume, capillary dilation and general obstruction (or not) of blood vessels). These are all good proxies for general health.

Drugs lowering your resting heart rate do not indicate this in the same way.