
A hot bath has benefits similar to exercise - walterbell
http://theconversation.com/a-hot-bath-has-benefits-similar-to-exercise-74600
======
joshgel
Exercising (moderate physical activity) for 2-2.5 hours per week leads to a
20% reduction in all-cause mortality (not to mention its many other benefits).
Exercising for an additional 5.5 hours leads to another 20% reduction.

No preventative intervention we have in medicine leads to that kind of gains
(except maybe quiting smoking).

Articles like this are probably causing harm to the people that read them by
discouraging them from exercise [conjecture]. Until I see rigorous mortality
data on taking bath, I think I'll stick to my exercise routine...

Source:
[https://www.cdc.gov/physicalactivity/resources/recommendatio...](https://www.cdc.gov/physicalactivity/resources/recommendations.html)
(see 2008 Physical Activity Guidelines Advisory Committee Report [PDF -
4.5MB])

~~~
zeteo
> Exercising (moderate physical activity) for 2-2.5 hours per week leads to a
> 20% reduction in all-cause mortality (not to mention its many other
> benefits). Exercising for an additional 5.5 hours leads to another 20%
> reduction.

With a very important caveat in the report:

> Because all of the studies in the evidence base were observational
> epidemiologic studies with no randomized controlled trials, the data cannot
> prove causality of effect.

People who don't feel that great when they exercise (despite everyone urging
them to exercise) are probably not in the best health. The pervasive advice to
exercise more will by itself confound the studies, because healthier people
will tend to self-select into the "exercise" group.

~~~
joshgel
I agree with your comments entirely. I'll also add, however, that even though
this is cohort data 1) there is A LOT of data, almost all of it in agreement
for hundreds and hundreds of studies, over millions of person years and 2)
there is pretty strong evidence of a dose-response relationship. Both of those
two points _help_ (though don't entirely eliminate) the weaknesses inherent in
cohort data.

~~~
QSIITurbo
It doesn't change the fact that if you take approx 150 from each of the
activity groups, the cohort study will tell:

Approximately 5 from the "slobs" will die.

Approximately 4 from the "moderate exercise group" will die.

Approximately 3 from the "forrest gump group" will die.

On a personal level, to me these groups are more or less the same in terms of
mortality, but somebody marketed the 20% really well.

~~~
zeamaize
Well if you truly don't understand math, please transfer 20% of your wealth to
me. I mean, from your perspective it's the same amount of wealth, right?

~~~
tudorw
that's not the point, the posters point is that the way the math was used
added dramatic effect, it did not aid in understanding the meaning of the
findings.

~~~
QSIITurbo
Exactly. 20% or 40% sounds really big. In reality, you're maybe lowering your
chance to die (during some time) by less than 2% by exercising almost
constantly. Now, if you're not enjoying exercise, or feel exhausted after
exercising, you actually reduce the amount of "quality life" by exercising.

If exercise was a drug, they'd never allow it on the market.

~~~
DanBC
> If exercise was a drug, they'd never allow it on the market.

Plenty of drugs have much worse efficacy and "numbers needed to treat" figures
than exercise.

Current exercise advice is about 30 minutes per session with 3 sessions a
week.

~~~
QSIITurbo
Not really. Take your 30 minutes of exercise per week that will reduce the
chance of dying by 1% (2% is for the forrest gumps). Let's say you can do that
by spending 60 minutes a day (changing clothes, getting dressed / undressed,
showered and so on). In a 52-week year that will amount to loss of 156 hours
of your life. For 8-hour work days that's 19.5 workdays. A good vacation's
worth! No drug is allowed to do that.

And if you break your ankle or break your wrist or elbow when exercising,
it'll never be as good as new.

~~~
sten
What a silly set of arguments. Exercise is literally empty time for you with
no other benefit? Lets put aside the fact that you receive endorphin from
almost any exercise you do. You can't go to the beach, rock climb, play with
your kids/dog, etc.? No, must be productive all the time. Even if that was the
case, it's quality adjusted lifespan that counts for most people.

You may break your wrist sure. In the same way that you may get wrist injury
from typing too much. Exercise will reduce the likelihood of other injury.

~~~
QSIITurbo
Ugh, your comment is so stupid I can't even be bothered to think of a proper
reply.

------
fauigerzigerk
So exercise is good, fasting is good, heat is good, cold is good. It seems all
short term stress is good.

I'm waiting for the study that shows binge drinking is good :)

~~~
trentmb
Fasting seems like the opposite of stress- your digestive tract isn't actually
doing anything

~~~
robbiep
Actually, you're well off, but not for the reason you think. Let me explain.

Fasting invokes all your counter-regulatory hormones: cortisol, adrenaline,
others but they are the big players - because not having easy access to sugar
leads to a stress response.

So it isn't gut rest, it's physiological phase change that is causing the
stress response

~~~
agumonkey
How long is the stress response ? is it only transient before switching to a
"fasting" regime or is it long lasting ?

~~~
robbiep
I guess depends on your definition of a stress response; most people would
consider it to be a 'stress response' whilst you have high
adrenergic/sympathetic activity. Upon activation of the parasympathetic
nervous system there will be a gradual decrease in cortisol and a rapid
decrease in adrenaline.

Thyroid hormone is also going to be implicated somewhere along with a host of
other hormones so I have simplified but suffice to say it's shades of grey on
the way in and out

------
woliveirajr
> These activities – such as soaking in a hot tub or taking a sauna – may have
> health benefits for people who are unable to exercise regularly.

I would add not only "unable", but "unwilling". Some people don't get any
pleasure by exercising, and perhaps having 50% of the benefits of cycling is
better than having none.

~~~
nsxwolf
Count me amongst the unwilling! I can't wait for a magic bullet or pill that
gives me the results I want without trying. I'm supposed to feel guilty about
that admission, but I do not.

~~~
mej10
The problem with not exercising for HN-types is that your brain suffers
because of it. Your cognition isn't as good as it could be and will decline
faster than if you exercised. Also more likely to develop neuronal disorders
later in life, and those aren't very fun.

[https://en.wikipedia.org/wiki/Neurobiological_effects_of_phy...](https://en.wikipedia.org/wiki/Neurobiological_effects_of_physical_exercise)

~~~
DanielleMolloy
Does this take into account the time she could have spent learning new
programming skills?

Serious question. With pre- and post phases (changing clothes, shower) and the
post-sluggishness, the exercise that you are doing in your free time just to
do exercise can be quite an extra time investment.

(no anti-exercise opinion here, but I find it better to combine exercise with
commuting or real hobbies)

~~~
coldtea
> _Does this take into account the time she could have spent learning new
> programming skills?_

Because she can't find 30 mins per day (or less) not devoted to programming
skills or other stuff, to do exercise?

Does the question takes into account the less years of practicing those
programming skills because of earlier demise due to bad shape?

~~~
DanielleMolloy
Did you read and understand the second & third paragraph at all?

If yes, please name the type of effective exercise that you can complete in
30min, _including_ preparations and clean-up afterwards. Really curious.

(Commuting and hobbies that are not for the sake of doing exercise don't count
because they were already mentioned.)

~~~
coldtea
>Did you read and understand the second & third paragraph at all?

Yes, and I find it wrong.

I'm not sure what "preparations" and "clean-up" afterwards you imagine, sounds
like excuses not to do any or overthinking it.

It can be just doing some sets of repetitions of body only exercises, without
any equipment to put out (a towel on the floor will do). Or a jogging run --
no preparations, just putting on your running shoes and a shower afterwards.
Or dancing around in your room. And countless other ways (e.g. getting some
gym equipment, a stationary bike, etc).

One showers at the end or start of the day (or should) anyway, and that
doesn't have to take more than 5 minutes. And 30 minutes, or even 15-20
minutes, of exercise per day is more than enough to see health benefits.

In fact: "For most healthy adults, the Department of Health and Human Services
recommends these exercise guidelines: Aerobic activity. Get at least 150
minutes of moderate aerobic activity or 75 minutes of vigorous aerobic
activity a week, or a combination of moderate and vigorous activity".

------
flippyhead
I always figured that it's diversity of stimulus/experience/etc that is the
biggest factor. The operating envelope of our bodies (and minds) presumes
season changes, pretty much constant walking, and (typically) a very different
social environment. Putting how we modify all this with various drugs aside,
our environment in modern times is very different from the one our bodies
expect. Some of this seems better understood, like how the insane abundance of
sugar is something our bodies cannot cope with. Another interesting one is the
entire discipline of orthodontics; turns out our teeth would come in
completely straight if it weren't for all our soft processed food not giving
them the input they need to orient themselves correctly in our jaws. I suspect
exposure to cold and heat is simply another thing we've lost.

~~~
jacobolus
> _Another interesting one is the entire discipline of orthodontics; turns out
> our teeth would come in completely straight if it weren 't for all our soft
> processed food not giving them the input they need to orient themselves
> correctly in our jaws._

Do you have a source for this? Sounds interesting.

~~~
cm2012
Considering plenty of mummies had horrible teeth, I doubt it.

~~~
komali2
The Egyptians didn't each much better than us - lots of breads.

I would assume OP means by "feedback" the constant ripping and tearing of meat
and incessant chewing of highly fibrous plants and vegetables.

~~~
cm2012
Which doesn't mean highly processed foods, just not living like hunter
gatherers.

~~~
komali2
Well, I haven't seen a source for the claim that teeth were better when we
weren't eating soft food, but the Egyptians definitely ate soft food, so I
would assume that the hypothesis doesn't apply to them.

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clock_tower
How many years until we get the headline, "A hot bath doesn't have benefits
similar to exercise"? I predict five.

~~~
drcode
You basically summarized today's new episode of EconTalk, on the perils of
statistical significance:
[http://www.econtalk.org/archives/2017/03/andrew_gelman_o.htm...](http://www.econtalk.org/archives/2017/03/andrew_gelman_o.html)

~~~
clock_tower
The thought certainly isn't original to me! I think that Slate Star Codex and
The Last Psychiatrist both had pieces on the reproduction crisis, especially
in psychiatry, and I'll check this episode out as well.

------
100ideas
Wow crazy. The article ends by speculating that activities that activate “heat
shock protein” pathway may help blood sugar control. It’s interesting b/c this
pathway is well-studied in microbes like e coli and we were taught about it in
my genomics classes. But I didn’t realize it was conserved to the point that
it is significant in humans (maybe it isn’t).

It’s a bit of a misnomer, actually. It was identified in e. coli as
molecularly central to their response when exposed to immediate stress, such
as going from 32 C to 40 C, but also on exposure to UV, or cold?, pH change,
salinity change etc

Basically it’s bacterial-molecular version of calling 911. But because it was
first identified by heat shock experimental condition, that’s what it was
named.

Did the author just read about "heat shock protein" in humans and assume it
was related how gene expression changes in human cells when body temperature
is elevated 1 degree C? Or was it mentioned in the primary literature they are
summarizing...

------
pc2g4d
I always wonder about the effects of pervasive air conditioning. Living in
cool environments all through the summer certainly isn't natural, right? Maybe
the energy required to regulate body temperature in warm environments is
actually a good thing, and air conditioning prevents us from getting the
benefit.

~~~
acjohnson55
Some people also tout the benefits of mild hypothermia. I suppose any type of
thermal regulation is a workout for the body.

------
jwtadvice
I see a number of these articles from time to time about the health effects of
(warm|cold) water treatment.

Seems to me not to be a replacement for exercise, a healthy diet, and good
sleep. Maybe as a supplement. Or maybe for someone who is injured or old or
has limited opportunity.

Unfortunately good scientific work along these lines very often lead to
headlines that lead people to think: wow this is like a shake-weight but
there's a science paper proving it.

There's no replacement for hard work.

~~~
gph
>There's no replacement for hard work.

Not yet for physical health. But that saying kind of annoys me in a general
sense given that the majority of technological advancement has specifically
been to replace hard work we don't want to do. So there's good reason to
believe a technological solution for physical health that doesn't require hard
work will exist some time in the future.

~~~
tbrownaw
Does not follow.

Just because we _want_ something is not a good reason to think that it's
possible.

As I understand it, the health benefits of hard work are currently believed to
be an integral part of that hard work. And, they're at least somewhat
localized to whatever systems are doing the work.

Or from another perspective, weight machines and indoor air-conditioned
treadmills _are_ your technological solution.

~~~
cosmie
They're the _current_ technological solution, but they're essentially proxies
to condense a naturally occurring process into a more efficient process;
weight machines and treadmills provide an efficient method to work out
whatever systems your exercise regime is designed to affect. But what you're
after is the resulting byproduct of that exercise, not that exercise itself.

Similar to how biking uses the same inputs as walking, but makes it more
efficient. So if your goal is to get somewhere as efficiently as possible
rather than walking in and of itself being the goal, you're going to bike
instead. Then comes along the car and you're no longer constrained to the
natural capabilities of your body in order to travel, and it's a whole new
ballgame.

Exercise has a lot of health benefits because it _causes_ things in the body.
From stretching things to tearing muscle fiber to causing your body to
generate and release different hormones and steroids (and many, many other
effects).

The technological solution the OP wants is something which simulates the
effects of exercise on the body but without the exercise itself. Such as
nanomachines that can be designed to stress test different components of the
body and keep them active or that cause the same types of micro-tears in
muscular tissue that weight lifting does. As we learn more about the body, and
we make smaller and smaller machines that are capable of operating from within
the body, we can leverage those machines and that knowledge to directly
maintain an ideal state of fitness regardless of externalities such as an
individuals predilection or capacity for the level of working out needed to
maintain that ideal state.

------
fsiefken
So are 40 degree Celcius hot tubs as effective as 80 degree Celcius Sauna
sessions. I was just about to buy a portable sauna, but if a bath gives me a
similar effect I wouldn't buy it. Except that I can watch TV while I'm sitting
in my portable sauna chair and my S.O. lounges on the couch.

~~~
sushisource
I mean, buy one if you want one. I wouldn't buy it for this reason. It might
be sort of good for you, but so are lots of things as research constantly
reveals. A 30 minute run everyday will do way more for your health if you're
not exercising.

------
Mz
I bet that hot baths move lymph at higher than normal rates, just like
exercise. This is the mechanism by which our bodies cleanse our tissues.

But, that is considered "woo" by a lot of people. I am sort of annoyed at the
heat molecules explanation at the end of the article. Like, we can't just
admit that maybe our own body's mechanism for taking out the trash matters
when it gets pumped up to a higher rate? That is too...weird? or something?

------
waxing-gibbous
n = 7 per group, no control, main effect p ~ 0.05. Nothing to see here
unfortunately.

~~~
seanwilson
Yeah, I'm not sure why this is being discussed so seriously. There really
wasn't a control group?

------
akhatri_aus
Funny, because the comments on here a few months ago implied a cold water
shower does miracles for you too and practically bashed hot water cleaning to
oblivion.

------
halis
What I like to do is have a hot bath and then 30 minutes in take a freezing
cold shower for about 10 minutes then get back in the bath for 30 minutes,
followed by another freezing cold 10 minute shower.

If you think you can't do a freezing cold shower, you'd be surprised. Start
off luke warm and just keep lowering it little by little. Before long you'll
have the water all the way on cold.

Once it's cold I try to do 2-3 minutes on front, back, left and right.

This will get the endorphins flowing and is good for weight loss. I've also
read that it will release something in your body that tells it that it needs
to start burning fat reserves, which makes sense given our history.

~~~
tqkxzugoaupvwqr
I guess I’m not the bathing type, 1 h 20 min seems excessive too me. I rather
spend this time in the gym exercising and raking in all the additional
benefits compared to bathing.

------
fsiefken
Does anyone know where the Shutterstock picture has been taken? I haven't seen
a swimming pool with chess games in it. I once thought about playing with hive
pieces on the bottom of the pool. It'd be nice to read a book in bath or in
the water, but water and books don't really get along.

~~~
js2
"Szechenyi Baths (Budapest, Hungary), traditional Hungarian thermal bath
complex with spa treatments." \-- [https://www.shutterstock.com/image-
photo/budapest-hungary-no...](https://www.shutterstock.com/image-
photo/budapest-hungary-november-2-2008-szechenyi-205346587)

~~~
StavrosK
I've been there, it's great (and in a very nice building).

------
mtw
There are similar studies showing that regular saunas lower cardiovascular
risk and dementia risk up to 63% (a summary here
[http://outcomereference.com/causes/108](http://outcomereference.com/causes/108)
)

Like the hot bath study, these were limited to very specific populations
(Finnish). I have yet to see studies of hot bath or saunas on different
ethnicities or different locations.

At the end of the day though, nothing beats regular moderate exercise. It's
the only lifestyle that has no side-effects, cheap, accessible to everyone
anywhere, and with demonstrated short-term and long-term effects. Walk, run
5k, hike, bike to work, your heart and your family will be grateful!

------
r00fus
Were they measuring outdoor cycling or indoor (exercise bike)?

I think there's a huge qualitative difference between the two - breathing the
outside air (and absorbing the sun if I'm lucky) probably do much more to
improve my health and outlook than the simple calories burned.

~~~
atourgates
I don't think it matters for this study. They only measured calories burned
and inflammatory response, which, assuming the same amount of energy expended,
I'd expect to be identical cycling on a trainer or outdoors.

------
cik2e
Best news ever! Now I can finally justify my exuberant daily morning bath
ritual to my friends and family with more than just "I like it so stfu".

On a serious note though, I've always known how good I feel after a nice 30-60
minute soak so I'm not entirely surprised. But I'll be sure to keep the water
temp up from here on out though. I've grown accustomed to a "nice and warm but
not excessively hot" setting. Come to think of it, 40 C (104 F) might be where
I'm at already--that doesn't sound like a crazy high number. Perhaps it's time
to take things to the next level and install a bath thermometer along with
measuring my body temp pre and post bath.

------
Nomentatus
J Physiol. 2016 Sep 15;594(18):5329-42. doi: 10.1113/JP272453. Epub 2016 Jun
30. Passive heat therapy improves endothelial function, arterial stiffness and
blood pressure in sedentary humans. Brunt VE1, Howard MJ1, Francisco MA1, Ely
BR1, Minson CT2.

A recent 30 year prospective study showed that lifelong sauna use reduces
cardiovascular-related and all-cause mortality; however, the specific
cardiovascular adaptations that cause this chronic protection are currently
unknown.

[https://www.ncbi.nlm.nih.gov/pubmed/27270841](https://www.ncbi.nlm.nih.gov/pubmed/27270841)

------
nocoder
Such articles are so frustrating. What is with our fixation to trying to do as
little as possible for max. gains. It feels like there is this whole group of
individuals out there who are trying to convince (without solid evidence) that
exercise is replaceable my other things.Human beings are not efficiency
optimization machines. Moreover, everyone who exercises regularly can tell you
that fitness is the low hanging fruit. There are so many other benefits of
exercise like opportunity to meet new people & benefits to mental health and
more.

------
Gatsky
Hope you are heating your water with renewables.

A coal powerplant would produce ~ 8-10 pounds of CO2 to heat a bath, 3.5x more
than a shower.

[https://www.withouthotair.com/c7/page_50.shtml](https://www.withouthotair.com/c7/page_50.shtml)
[https://www.eia.gov/tools/faqs/faq.php?id=74&t=11](https://www.eia.gov/tools/faqs/faq.php?id=74&t=11)

------
pmoriarty
_" Water immersion resulted in a greater increase in body temperature compared
with exercise, as well as a greater reduction in average arterial blood
pressure."_

Was that reduction in blood pressure seen after the bath or only while in it?

If after, how long after?

I wouldn't be at all surprised if there was lower blood pressure while lying
still in a bath compared to while performing vigorous exercise. But what about
after?

------
peterwwillis
We've known for a long time that temperature will change calories burned at
rest, and a reduction in peak blood pressure is not the same as a reduction in
overall blood sugar. These same temporary effects can be gained merely by
slight changes in diet, and don't provide the other positive effects that
light exercise brings.

The comparison to exercise is quite misleading.

------
maruhan2
This is just a simply "I heard that ...", so take it with a grain of salt. I
heard that heat (such as sauna) can help you lose weight, but it also loses
muscle, so it's not a great method of diet.

------
mamon
There's also one significant downside: hot bath lower testosterone levels in
men, hurting fertility, so please don't do it if you are trying to make your
partner pregnant.

~~~
blacksmith_tb
There's certainly some evidence that hot baths reduce sperm counts[1] but
nothing I see about testosterone levels. At the same time, it's clear that men
in cultures with traditions of soaking or saunas do still seem to father
children...

1: [https://www.ucsf.edu/news/2007/03/5541/hot-tubs-hurt-
fertili...](https://www.ucsf.edu/news/2007/03/5541/hot-tubs-hurt-fertility-
ucsf-study-shows)

~~~
cableshaft
Damn. My muscles have been feeling more fatigued lately and I was planning to
start going to a hot tub on a semi-regular basis :/.

------
drpgq
I wonder how cold a bath has to be to get the same calorie burn as for 40C
water.

------
ForFreedom
Warm bath would be better than hot bath.

------
HillaryBriss
hasn't this sort of practice been a common thing in Japan for centuries?

~~~
Jtsummers
Yes, but a common practice doesn't mean that whether or how it's beneficial
has been studied.

------
stretchwithme
My feeling is that diabetes is, at least in part, caused by poor circulation.
The peripheral neuropathy commonly associated with diabetes may actually be
caused by poor circulation as well, not by diabetes.

If blood flow to your limbs is impaired, your limbs can't process insulin very
well.

Given this view, anything that promotes circulation is going to help diabetes.

