It's very difficult to contort the causal arrow from the obvious explanation (that sick people don't use saunas very often) to less obvious ones (that saunas stimulate something in the heart to improve cardiovascular health). But boy, do they try.
However, I can certainly imagine that a sauna gets your heart rate up and your metabolism into overdrive trying to cool you down.
The human body burns roughly a fixed set of calories--it simply shunts those calories between the systems it considers to be immediately important.
If you are shunting one or two hundred calories a day to cooling yourself off, that's a bunch of calories your body can't throw at creating chronic conditions.
> If you are shunting one or two hundred calories a day to cooling yourself off, that's a bunch of calories your body can't throw at creating chronic conditions.
Somewhere I read the comment that, to a first approximation, everything is related to everything else. It comforts me a little when I see another example of these incessant articles about how X may cause Y.
In Finland even "sick" people go to the sauna all the time. It depends on the sickness though: fever and sauna don't mix for obvious reasons. But otherwise people do it.
Looking at the list of ailments in the article, I don't see them being a showstopper for going to a sauna.
For example, regular sauna is often helpful for people with asthma. The Finnish sauna is humid (one throws water to the hot rocks). There are variants within Finland too: a smoke sauna + asthma might not work.
My point is: the argument of "sick people do not use sauna" is false.
Finnish saying: "if tar, booze or sauna does not cure you, it is fatal". (Tar was used for skin ailments and wounds etc.)
I'm willing to entertain the possibility. And, unlike most things that people try to peddle with low-quality evidence, going to a sauna isn't obviously unhealthy. So, it's low risk.
The bigger issue is that observational results often invert cause and effect, and without any clever instrumental perturbation, such studies are merely hypothesis generating.
The article mentions some of the benefits. For example:
"Two recent experimental studies by Lee et a and Laukkanen et al in 100 men and women (56% men; age, 32-75 years) with at least 1 cardiovascular risk factor reported reductions in both systolic BP and diastolic BP after 30-minute sauna bathing sessions. In addition to reductions in BP, sauna bathing led to positive alterations in measures of arterial stiffness such as pulse wave velocity."
I don't have the time to read through the article, but I would bet that there are no active controls used. In other words, yes, blood pressure after a sauna bathing session is probably lower, but that is probably true for a variety of leisure activities, so what's the point of stating the obvious?
The more interesting research question is under what circumstances would a sauna bath be recommended over other interventions?
I don't mean to knock this paper in particular, the lack of active controls is endemic to academic research in health.
I've got a hot tub, and I've always thought that a 5-10 minute dip in 105 degrees gave me the benefit of a fever without the caloric expenditure. Plus, it really makes the joints stop aching.
Regular saunas are common in Sweden and Finland but rare in Scotland. It is quite possible that who uses saunas regularly and how they live is what matters and not the sauna at all.
This is interesting but I'd like to see a comparison with not using sauna at all. If 4x/week is better than 1x/week, in theory it could be because 1x/week is bad for you.
Once when I had a fever, I set my sauna to 40C and read books there. I have no idea whether it helped or not but it was very comfortable - much better than shivering in bed.
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[ 8.7 ms ] story [ 57.6 ms ] threadHowever, I can certainly imagine that a sauna gets your heart rate up and your metabolism into overdrive trying to cool you down.
The human body burns roughly a fixed set of calories--it simply shunts those calories between the systems it considers to be immediately important.
If you are shunting one or two hundred calories a day to cooling yourself off, that's a bunch of calories your body can't throw at creating chronic conditions.
... or fighting off chronic conditions either.
And, yes, doing this does remove calories from the ability to fight off "acute" conditions.
It's a tradeoff.
Well, of course. Fighting off the creation of chronic conditions.
In Finland even "sick" people go to the sauna all the time. It depends on the sickness though: fever and sauna don't mix for obvious reasons. But otherwise people do it.
Looking at the list of ailments in the article, I don't see them being a showstopper for going to a sauna.
For example, regular sauna is often helpful for people with asthma. The Finnish sauna is humid (one throws water to the hot rocks). There are variants within Finland too: a smoke sauna + asthma might not work.
My point is: the argument of "sick people do not use sauna" is false.
Finnish saying: "if tar, booze or sauna does not cure you, it is fatal". (Tar was used for skin ailments and wounds etc.)
The bigger issue is that observational results often invert cause and effect, and without any clever instrumental perturbation, such studies are merely hypothesis generating.
"Two recent experimental studies by Lee et a and Laukkanen et al in 100 men and women (56% men; age, 32-75 years) with at least 1 cardiovascular risk factor reported reductions in both systolic BP and diastolic BP after 30-minute sauna bathing sessions. In addition to reductions in BP, sauna bathing led to positive alterations in measures of arterial stiffness such as pulse wave velocity."
https://www.mayoclinicproceedings.org/article/S0025-6196(18)...
The more interesting research question is under what circumstances would a sauna bath be recommended over other interventions?
I don't mean to knock this paper in particular, the lack of active controls is endemic to academic research in health.