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Sauna effect on heart rate

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Re: Sauna effect on heart rate

#181

Post by dtran »

atum47 wrote: post #161

Should I assume a steam room has the same effect? I prefer it over sauna

Potentially, but likely much less effective and less studied, and you likely need longer sessions for effective dosage.

Most of the studies I've seen on improvements in blood plasma volume from passive heat are usually done with sessions in saunas with temperatures > 150 degrees F (60 C). Steam rooms usually only get up to 120F (~49C) even though the humidity probably makes it feel warmer.

Copying and pasting some of my reply to another comment above

Re: Sauna effect on heart rate

#182

Post by gjulianm »

HelloMcFly wrote: post #178
gjulianm wrote: post #71

Earlier quoted context omitted.

Much of that body of evidence relies on self-reported and self-assigned sauna usage rather than actual randomized trials, and also the papers show massive risk reductions that do not really fit with the country-level data (e.g., if saunas are that good for cardiovascular health and finns use them that much, why do they have similar rates of CV disease as neighboring countries that don't use that much sauna?)

Much of it is, sure, but certainly not all of it! On your comparison to Sweden, be cautious! Finns generally have a higher risk and incidence of cardiovascular disease compared to native Swedes - in fact, they have some of the highest risk in the world! Research from Earric Lee and/or Jari Laukkanen from this past decade will have clinical trials with controlled groups rather than just long-term population tracking.…

The first study shows a 0.37 hazard ratio for frequent sauna use. That’s better than a lot of the HRs reported for physical activity. It’s even better than not smoking. It just doesn’t really fit.

Also, the fact that there are practically no sauna related studies outside of Nordic populations is suspicious too. I bet that with those hazards ratios a lot of people have tried to study the effects more, it’s suspicious there’s practically nothing out there.

Re: Sauna effect on heart rate

#183

Post by gjulianm »

jampekka wrote: post #133
gjulianm wrote: post #126

Earlier quoted context omitted.

> of estimate of mean But you can't really assume that the estimate of the mean represents the real value. For example, if the sensor is equally likely to show 80 or 81 BPM when the real heartrate is 80.7, the mean estimator will be biased. > with 100 measurements Also, wearables aren't taking 100 measurements of the BPM at a given point in time. I think the highest frequency they usually have is 1 second measurement…

> But you can't really assume that the estimate of the mean represents the real value. For example, if the sensor is equally likely to show 80 or 81 BPM when the real heartrate is 80.7, the mean estimator will be biased. Bias is different from precision. If both conditions have the same bias, their difference is still unbiased. > Also, wearables aren't taking 100 measurements of the BPM at a given point in time. I th…

> Bias is different from precision. If both conditions have the same bias, their difference is still unbiased.

Not really, and I wouldn’t assume that when the condition under study can also affect how the measurement is taken.

> If you quantize so much that you have no variance in the measurements, then sure. But watches typically have 1 bpm quantization, which is fine at the scale of variation in HR.

At the scale of variation in HR in general yes, but not if the difference you’re trying to measure is in the range of 3 BPM.

> If you have independent error in measurements and quantization that gives you variance in measurement

That’s a big if. I am not confident we can claim that the errors are independent in this case, using sauna or not can affect how the sensor measures BPM.

Re: Sauna effect on heart rate

#185

Post by PaulDavisThe1st »

jagged-chisel wrote: post #65
mminer237 wrote: post #40

Earlier quoted context omitted.

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…

Your heart is also a muscle.

... about the size of your fist. Keep loving, keep fighting.

(attributed to Bertolt Brecht)

Re: Sauna effect on heart rate

#186

Post by PaulDavisThe1st »

bluecalm wrote: post #140
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…

For endurance training the main benefit of heat training is raising blood volume. Lungs are not a limiter. Developing stroke volume I imagine requires much higher intensity but that's just a wild guess based on my limited understanding of physiology. If heat training is better than another interval session remains to be seen but it seems a lot of smart people believe it's worth it nowadays.

and specifically, to be clear, plasma volume.

Re: Sauna effect on heart rate

#187

Post by willnz »

pegasus wrote: post #132
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'…

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?.…

I recently got an outdoor sauna at home, and that's definitely a key benefit ...sitting in silence without any devices, no smart phones, watches or music for at least 15-20 minutes.

Re: Sauna effect on heart rate

#188

Post by [deleted] »

trklausss wrote: post #70
ricardobayes wrote: post #34

Earlier quoted context omitted.

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…

For all we know, there is a link between cardiac/circulatory problems and arteriosclerosis (that is, loss of elasticity of the vessels). So it could be that exercise helps keep this elasticity, the same way maybe sauna does? Also antioxidants from vegetables etc. So it could be that it is a _factor_, but definitely needs way more study. I am also not in the medical field, but I think arteriosclerosis is a well known…

[deleted]

Re: Sauna effect on heart rate

#189

Post by PaulDavisThe1st »

austinthetaco wrote: post #94
kyriakosel wrote: post #58

Earlier quoted context omitted.

i was mostly refering to humidity/duration/temperature given that most devices do not report back these values

I'm equally confused as the other person above. Why not just ask participants to report what type of sauna they used? Sure humidity/duration/temp would be awesome to have, but at the very minimum knowing if a dry sauna would get the same results as a traditional steam sauna.

There's quite a wide range of variation between "full dry" (no added humidity whatsoever) and "full steam" (an actual steam room, rather than a sauna). Just asking people was it dry or was it humid won't capture much of that variation. I have a steam room at home and have been a near-life-long lover of them - they are wildly different than a sauna. But I'd still rank a sauna where someone had dumped 1L or so of water over the heater to be "humid", and consider it also very different from a totally dry sauna.

Re: Sauna effect on heart rate

#190

Post by PaulDavisThe1st »

pstuart wrote: post #130
lazyant wrote: post #99

Earlier quoted context omitted.

Would a hot tub session (say at 100 - 105 F) be comparable or yield similar results?

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...

David Roche, a notable running coach (and runner), and his co-coaching wife (and runner) Dr. Megan Roche (MD/PhD) seem to think that hot tubs need to be at least 106F to generate much of a heat shock response, which is normally what one is looking for in the context of post-exercise heat exposure. I should note, however, that they are mostly reading the same research papers as everybody else, not doing primary studies themselves.
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