I believe there are some heavy metals that you can only really get out of your body via sweating. But “granola” people have built up a whole story about sweating and toxin clearing that AFAIK has no basis in science.

It's probably hard to measure, but subjectively one feels better and thinks more clearly, so call it what you will. Saying that something is not affirmed by science is not equivalent to saying it is denied by science.

> It's probably hard to measure

No, mass spectrometers are not that hard to operate.

> subjectively one feels better and thinks more clearly

How is that related to toxins? Is coffee also removing toxins because it helps me think more clearly in the morning? Is complaining about public transport to a friend also removing toxins because it makes me feel better?

> Saying that something is not affirmed by science is not equivalent to saying it is denied by science.

Thankfully science has given us tools to base our conclusions on more than our fallible subjective impressions and whimsical correlations. "It seems to help, must be that we're removing something bad" is how you get bloodletting.

So based on the unnecessarily hostile feedback I can now explain that I was using the word toxin quite loosely and simply meant some undesirable waste products in the body. I did not actually mean tetrodotoxin or something like what a puffer fish would give you on a not-so-friendly poke. Sweating out waste products helps, and the heat also sticks with you for a while after a sauna session or a long bath, so that probably stimulates the organs into doing their natural processes better, clearing out yet more waste products. I don't get why this is such a contentious claim, either you get benefits from it and you do it, or you live your whole life waiting for someone else to prove its good before you try it out for yourself. I remind you of the incompleteness theorem, that there are truths that are true yet are unreachable by axiomatic induction.

> I remind you of the incompleteness theorem, that there are truths that are true yet are unreachable by axiomatic induction.

Science can strictly speaking not prove any truth, so the incompleteness theorem is irrelevant. Science tries to establish useful models. A model's usefulness is determined by its ability to predict the future (roughly speaking), whereas models whose predictions turn out untrue are eventually discarded.

It is perfectly fine to throw in hypotheses for how things work - that's how science advances. But there is a fine line between suggesting a causation and assuming that it is true just because it makes sense but hasn't been scientifically tested yet. That's more or less the opposite of science, which is (I guess) why there has been a relatively strong response to your statements. That way lies healing crystals.

>Science can strictly speaking not prove any truth

Could you elaborate on this?

Absolutely wrong, toxin has a very specific and concrete meaning ("a harmful substance produced within living cells or organisms") so if you're going to employ that word in this context you better be prepared to justify it by measuring aforementioned toxins and defining exactly what those physical substances are.

Okay, toxin is not the word I ought to have used, thanks. Gonna go with "waste products."

Citation needed for that first part. A quick google says there is no evidence that sweating out toxins improves health and the liver and kidneys remove far more toxins than sweat glands

Right it’s right up there with getting your back cracked to improve digestion

https://www.google.com/amp/s/www.nytimes.com/2017/08/18/well...

It's very rare to need to remove toxins from your body.

Toxins are naturally occurring poisons of plant or animal origin. Not heavy metals, not man made toxic chemicals. The word is widely misused.

If you have been poisoned by a snake, octopus, or platypus, seek medical help rather than the sauna. Stung by a nettle, maybe.

Fresh air is usually nicer than stale, old air. And when one sweats out "old water" it gets replaced by the fresh water one intakes. I bet if we collected enough sweat from sauna-goers and sprinters we would find things in it that you would rather have not in your body. Of course, I can already hear the chorus of indolence cheer "there's no science to support this claim" and yet there is also no science to deny it. The body is a gigantic circulatory system, out with the old, in with the new, I don't see why it would be any different with sweat.

Sweat does contain more than water and salt (urea for example). This is actually long established. But these substances are hardly toxins, even though the body has reasons excreting them.

It's still unclear how you think the concentration of these things on the skin will be lower with sweat dripping down (and evaporating) than when surrounded by a hundred liters of bathwater though.

My reasoning was pretty simple: if you sit in a bath things can leave your body and also have ample opportunity to re-enter your body. Your comment on relative concentrations is helpful and makes me reconsider this notion. As a naive and simple-minded person I think of entering a bath whilst covered in mud. Yes, the relative concentrations of mud on my skin's surface and mud in the water would clearly suggest I am "clean," but will I really feel clean stepping out of a tub that looks more opaque than clear? Maybe it is no surprise I have such trouble understanding the world with my simple-minded approaches.

Yeah, people misuse the word "toxins" to mean "toxic environmental chemicals". It actually means a naturally occurring poison from an animal or plant.

They are like evil spirits.