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Sauna effect on heart rate

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Re: Sauna effect on heart rate

#41

Post by lccerina »

kyriakosel wrote: post #2

Author here. Methodology upfront because I'd ask the same things: Data: daily records from wearable users who logged sauna sessions via connected apps. Within-person design — each user is their own control, comparing their own sauna-day nights against their own non-sauna-day nights. No cross-user comparisons. Stats: paired t-tests, FDR-corrected p 0.2 threshold for "meaningful effect." Anything below d=0.2 we don't r…

If this was a peer-reviewed paper, it won't pass.

- Is the wearable accurate enough to be sure that 3bpm is not a measurement fluke? - Why did you use the minimum heart rate value (which could be a measurement glitch) and did not compare a percentile (e.g., 2.5th lowest percentile)? - Were all assumptions for paired t-testing valid? How did you account for likely temporal correlations in the data (e.g., sauna could have an effect also on a night 2 days after it, same for exercise)? - How can you define a "comparable-intensity exercise day" if you don't know the characteristics of the sauna?

Re: Sauna effect on heart rate

#42

Post by nyjah »

bluGill wrote: post #6
kyriakosel wrote: post #2

Author here. Methodology upfront because I'd ask the same things: Data: daily records from wearable users who logged sauna sessions via connected apps. Within-person design — each user is their own control, comparing their own sauna-day nights against their own non-sauna-day nights. No cross-user comparisons. Stats: paired t-tests, FDR-corrected p 0.2 threshold for "meaningful effect." Anything below d=0.2 we don't r…

The most important thing you didn't measure: does this affect long term health in the same way exercise it known to. That is can I put a TV in my sauna and watch that for an hour every day instead of getting out and exercising - yet get the same better long term health outcomes? My current guess is no. That is this improves a marker for good health without improving health. However this is a guess by someone who isn'…

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.

Re: Sauna effect on heart rate

#43

Post by jtanderson »

kyriakosel wrote: post #2

Author here. Methodology upfront because I'd ask the same things: Data: daily records from wearable users who logged sauna sessions via connected apps. Within-person design — each user is their own control, comparing their own sauna-day nights against their own non-sauna-day nights. No cross-user comparisons. Stats: paired t-tests, FDR-corrected p 0.2 threshold for "meaningful effect." Anything below d=0.2 we don't r…

Just as a discussion point: how do you think these effects would translate (if at all) to regularly practicing hot yoga, say around 100-105F? Intuitively, it would combine the effort + recovery, but probably not enough time elapsed in the same session for the sweat benefit during muscle repair?

Re: Sauna effect on heart rate

#45

Post by rhyperior »

mminer237 wrote: post #40
nsbk wrote: post #21

Earlier quoted context omitted.

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…

Edit: I posted this accidentally when editing without noticing. Hypertrophy isn't necessarily a bad thing. I thought I was discarding the comment cuz I realized I was out of my depth. whoops Please ignore my comment, though I will leave it to make the below comments less confusing. Original: You don't want to "work out" your heart though. Cardiac hypertrophy is a bad thing. The benefit of exercise is that your muscle…

That seems… misguided.

Sources?

Re: Sauna effect on heart rate

#46

Post by joelthelion »

lccerina wrote: post #41
kyriakosel wrote: post #2

Author here. Methodology upfront because I'd ask the same things: Data: daily records from wearable users who logged sauna sessions via connected apps. Within-person design — each user is their own control, comparing their own sauna-day nights against their own non-sauna-day nights. No cross-user comparisons. Stats: paired t-tests, FDR-corrected p 0.2 threshold for "meaningful effect." Anything below d=0.2 we don't r…

If this was a peer-reviewed paper, it won't pass. - Is the wearable accurate enough to be sure that 3bpm is not a measurement fluke? - Why did you use the minimum heart rate value (which could be a measurement glitch) and did not compare a percentile (e.g., 2.5th lowest percentile)? - Were all assumptions for paired t-testing valid? How did you account for likely temporal correlations in the data (e.g., sauna could h…

> 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.

Re: Sauna effect on heart rate

#47

Post by derektank »

Jtarii wrote: post #32
bluGill wrote: post #6

Earlier quoted context omitted.

The most important thing you didn't measure: does this affect long term health in the same way exercise it known to. That is can I put a TV in my sauna and watch that for an hour every day instead of getting out and exercising - yet get the same better long term health outcomes? My current guess is no. That is this improves a marker for good health without improving health. However this is a guess by someone who isn'…

A sauna will do nothing for muscular-skeletal health.

That seems like a very strong statement. Isn’t there evidence that Heat Shock Proteins are produced in response to time in the sauna, which have beneficial effects on muscle growth and repair?

Re: Sauna effect on heart rate

#48

Post by z3t4 »

bluGill wrote: post #6
kyriakosel wrote: post #2

Author here. Methodology upfront because I'd ask the same things: Data: daily records from wearable users who logged sauna sessions via connected apps. Within-person design — each user is their own control, comparing their own sauna-day nights against their own non-sauna-day nights. No cross-user comparisons. Stats: paired t-tests, FDR-corrected p 0.2 threshold for "meaningful effect." Anything below d=0.2 we don't r…

The most important thing you didn't measure: does this affect long term health in the same way exercise it known to. That is can I put a TV in my sauna and watch that for an hour every day instead of getting out and exercising - yet get the same better long term health outcomes? My current guess is no. That is this improves a marker for good health without improving health. However this is a guess by someone who isn'…

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.

Re: Sauna effect on heart rate

#49

Post by RankingMember »

ricardobayes wrote: post #34
bluGill wrote: post #6

Earlier quoted context omitted.

The most important thing you didn't measure: does this affect long term health in the same way exercise it known to. That is can I put a TV in my sauna and watch that for an hour every day instead of getting out and exercising - yet get the same better long term health outcomes? My current guess is no. That is this improves a marker for good health without improving health. However this is a guess by someone who isn'…

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 bruta…

> I'm not arguing that excercise is unhealthy, it's just that its contribution to eventual longevity, is currently unknown

I see numerous studies indicating that exercise contributes directly to eventual longevity, e.g.:

https://www.ama-assn.org/public-health/prevention-wellness/m...

https://www.acc.org/latest-in-cardiology/articles/2025/07/02...

https://pmc.ncbi.nlm.nih.gov/articles/PMC3395188/

Re: Sauna effect on heart rate

#50

Post by quickthrowman »

LeCompteSftware wrote: post #20
stevekemp wrote: post #4

[flagged]

No, it seems saunas have very low relative humidity except for briefly after you splash the hot rocks. "Relative" is the key term there: the absolute humidity is high, but the hot air can accept much more H20 and it will suck moisture off your body. So it is a dry environment according to humans. According to this company plus some sketchy math I just did, the relative humidity can swing between 15% and 40%: all over…

Yeah, I’ve taken hundreds of (Finnish) saunas (both electric and woodfired) and they all have one thing in common: they’re dry. It’s a bit more humid when you throw water on the rocks, but it generally stays between 10-40% RH. This is a good thing, as 90% RH at 90C would be uncomfortable to say the least.
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