
Perceived Physical Activity and Mortality: Study - giffarage
https://www.health.harvard.edu/blog/mind-over-matter-how-fit-you-think-you-are-versus-actual-fitness-2017081412282
======
whack
With the first study, I notice that they didn't take into account the
participants' general attitudes and happiness levels. It's possible that the
people who "thought they were more active", felt that way because they were
more optimistic/confident/happy in general, which in turn leads to the
reduction in mortality.

The second study is more convincing, since it relies on randomly assigned
groups. However, I don't think they measured the participants' actual level of
activity during the course of the experiment? It's possible that the different
interventions led to differences in activity level, during the experiment
period, which led to the physiological improvements later seen.

Perhaps I'm being overly cynical in not accepting the study's conclusion. It
just seems too fantastic, that someone can lose weight and reduce their
mortality, merely by deluding themselves on how active they really are.

~~~
hshehehjdjdjd
Yes, a hidden factor seems far more likely. There is probably some secondary
variable that affects both your mortality rate and your perception of your own
fitness. This seems much more likely, even to the point of seeming obvious.

~~~
chiefalchemist
Feel like it might be being optimistic. I believe "positive outlook" at the
very least has correlated with better health, longevity, etc.

Feeling in better shape (and not actually being so) is a byproduct of
optimism.

~~~
usrusr
"Being healthy makes people feel healthy" (and thus more
optimistic/active/positive) would be the more occhamish interpretation of that
correlation.

~~~
chiefalchemist
But I think it goes both way, with anticipation driving outcome as much as if
not more than the other way around. That's the gist of the study. How you feel
is more important than how healthy you actually are.

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yk
I would read that as "adhoc guess of people outperforms statistical model," so
the model probably misses some factor that people just take into account. As
an example, someone who knows that they have cancer and that therefore their
health will rapidly decline in the near future will likely not report that
they are leading a healthy and active live, even though data right know shows
that they are trying to keep in good shape. Or a combination of many similar
but less spectacular things.

Not to belittle the researchers, but trying to outperform a brain that gets
data about the individual situation 24 h a day is a quite hard task.

~~~
dcow
Outperforming the brain is different from making poor assumptions regarding
data collection, isn't it? It sounds like in your example the model is not
winning because of inaccurate setup but at the end you're conceding that
humans might just be innately better than the model.

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wufufufu
I wish physical movement was somehow integrated with software engineering
more. Weak solutions like standing desks don't make it the cardio equivalent
of something like a cleaning job.

It's sad that we sacrifice health for more money only to spend it on health-
related issues we accumulate from our career choice.

I always thought that maybe having to carry a medicine ball up a hill in order
to deploy a service would be fun.

~~~
brandonmenc
I love to exercise - but I really like being able to keep that separate from
other aspects of my life.

I've worked manual labor jobs. They suck, and they damage your body. If you
think sitting all day long is bad for your health, imagine what even just
pushing a broom thousands of times a day is doing to say, your rotator cuff.

Pack a healthy lunch, keep your hours reasonable, get up from your desk and
walk around every couple hours, exercise in your free time, and your office
job won't kill you.

As to which type of job is more "fun" \- a construction foreman once told me
that he always sees these guys who try working construction to get away from
their office job, who try to find meaning/enlightenment through manual labor -
a sentiment you hear here a lot - and they always go back to their office job.
Always.

But the guys who manage to escape the jobsite for the office - they never,
ever come back.

~~~
j9461701
And yet construction workers were the happiest group surveyed:

[https://www.linkedin.com/pulse/construction-workers-
topped-r...](https://www.linkedin.com/pulse/construction-workers-topped-
rankings-happiest-employees-matt-jones)

Personally, I really couldn't agree more with what you're saying. The prospect
of doing manual labor for a living just sounds awful. Getting dirty and
smelly, blowing out my knees and ruining my back, having my brain stuck in
idle for 8 hours all day every day, massively increasing my probability of
suffering a crippling or fatal work-related accident. And an office job has
the possibility of leading to a work-from-home situation, which would allow
you to get whatever level of exercise of whatever type you want every single
day of the week.

~~~
visarga
> having my brain stuck in idle for 8 hours all day every day

You'd be surprised how many times manual labor requires solution finding. Even
figuring out a leaking pipe or a problem in the electricity panel requires
ingenuity. Designing and making custom furniture can be complex. A competent
construction worker / repairman can be like a dev and payed like one (&
sometimes harder to find). Take a look at those DIY videos to see what I mean.
Not to mention the tooling these guys have in their shops ...

~~~
wufufufu
Yea, the opinion that you can only use your brain in an office job is wrong,
but that opinion is somehow is imprinted on everyone.

I know people who work(ed) construction who are actually very smart and they
constantly belittle their own intelligence because they don't have a college
degree or have a job that works with computers. Vice versa I know people who
attend graduate school at tech institutes who are actually stupid in many ways
but are so full of themselves because they've managed to memorize enough to
pass engineering classes.

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arkades
The little review “suggesting that how fit you think you are affects your risk
of death more than how fit you actually are,” seems to not have parsed the
studies it claims to be quoting.

“No matter how they ran the numbers, if people thought they were “a lot less
active” than their peers, this was associated with a statistically significant
higher risk of death: at least 18% when compared to the general population
(those whose data were not included), and up to 71% higher when compared to
people who thought they were “more active.” Again, this is regardless of
actual physical activity or other health risk factors (smoking, being
overweight, etc.).”

This was -after- controlling for actual fitness (eg. BMI). That doesn’t mean
“perception matters more than BMI,” it means “perception matters a lot in
explaining the variance that remains after removing all the variability
explained by actual fitness.”

The second study wasn’t just about “activity perception.” It came with a
positive message from authority figures, and offered an additional validation
of an otherwise low-prestige job. Both of these things might contribute to a
motivation-driven short term effect that has nothing at all to do with long
term self-perception not long term mortality.

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rossdavidh
While I don't doubt that thinking of yourself as fit helps (not least by
encouraging you to remain more active), I have to wonder if people who feel
physically unwell on a frequent basis are not more likely to think of
themselves as not fit.

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0xcde4c3db
> No matter how they ran the numbers, if people thought they were “a lot less
> active” than their peers, this was associated with a statistically
> significant higher risk of death: at least 18% when compared to the general
> population (those whose data were not included), and up to 71% higher when
> compared to people who thought they were “more active.” Again, this is
> regardless of actual physical activity or other health risk factors
> (smoking, being overweight, etc.).

Knee-jerk, hobby-horse-compliant hypothesis: reduced levels of perceived
activity are a symptom of below-average/impaired interoception [1], and
effects of that deficit (less efficient homeostatic feedback, inability to
recognize progressive injury and illness in its early stages) are responsible
for the increased mortality.

[1]
[https://en.wikipedia.org/wiki/Interoception](https://en.wikipedia.org/wiki/Interoception)

> Interoception is contemporarily defined as the sense of the internal state
> of the body. It encompasses the brain’s process of integrating signals
> relayed from the body into specific subregions—like the brainstem, thalamus,
> insula, somatosensory, and anterior cingulate cortex—allowing for a nuanced
> representation of the physiological state of the body. This is important for
> maintaining homeostatic conditions in the body and, potentially, aiding in
> self-awareness.

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chiefalchemist
> "Our mindset affects our motivation."

It effects more than motivation. Take stress for example. Under stress - e.g.,
"am I fit enough?" perhaps? - the body releases cortisol. To the best of my
knowledge, cortisol has been linked to weight gain. Stress effect sleep, which
has system-wide implications. Etc.

The mind is the body and the body is the mind. The Western separation of the
two is a myth that should be considered irrelevant at this point.

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himom
Wasn’t there a study of hotel cleaners whom had an overall increase in health
because they were told their jobs already included exercise? This also seems
like a self-fulfilling prophecy effect, whereby a “healthy” thinking person
makes slightly different choices than someone else whom believes themselves to
be “unhealthy.”

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jg42
I can't get the math to work to reach 475 million American adults.

Our current population is only 347 million and the birthrate is about 1.25%.
Running a total for the last 20 years or so I can't get more than 300 million
adults or so.

Any math folks that want to analyze the number of unique adults
entering/leaving the US from 1990 to 2011?

~~~
spicymaki
I think idea is the sample size of 60k was varied enough to represent a
population size of up to 475M. More than enough to reflect the real population
and then some.

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frabbit
Perceived Physical Activity and Morality would also be an interesting study.

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blunte
It's quite difficult to measure a potential reality that could be outside
accepted reality using the tools of accepted reality.

That is to say, there are so many cases of thoughts seeming to affect reality
that are difficult or impossible to explain with existing science. Those who
do not accept such possibilities naturally do not see proof of them, and those
who do accept those possibilities may see them or even perhaps imagine that
they see them when there may be a simpler explanation.

I find it ironic that some rabidly religious people cannot accept any
explanation for events other than what their book(s) tells them, while at the
same time strictly "scientific" people likewise behave the same, but using
different books. Neither group sees their mirror image in the other...

~~~
TheDong
> so many cases of thoughts seeming to affect reality that are difficult or
> impossible to explain with existing science

Rather, science has explained many of these cases already.

Humans are prone to confirmation biases, are really bad at probability, and
have quite faulty memories.

Those facts combined result in phenomenon that exist outside science because
any time science sheds light upon them, it turns out that it is a construct of
the human brain unrelated to reality.

> strictly "scientific" people likewise behave the same, but using different
> books

Scientific people do not hold on to books with no evidence and accept
challenge. Science is more about the methodology and reasoning than about the
current conclusions. If a scientist is ignoring something counter to their
books, it's because the books have provided more scientific evidence than the
challenging opinion.

There's a massive difference here, and simplifying science down to "it's like
religion, but the bible is other scientist's books" is neither helpful nor
accurate.

~~~
blunte
I did not simplify it as you state, and I certainly did not make a blanket
statement.

But regarding science and possibilities, how often in history had science said
somethingwas not possible or real, and by rules of science at that time they
were correct, but later with more understanding science began to allow the
observed thing to be "real".

Science, its definitions and rules, are ever changing and advancing. Thus it
is fair to say that at any given time we are dumber than we will be in the
future.

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axilmar
...or people can "feel" their general status and therefore those that think
they will not live long didn't actually live long.

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dhbradshaw
People had a measure of fitness that was accessed by asking "how active / fit
are you?"

Researchers had a different measure of fitness.

If the researcher's measurements are less predictive than people's estimates,
one possible reason is that there's some powerful mental effect going on.

However, a more parsimonious interpretation might be that self-perceived
fitness was a better measurement than the one the researchers came up with.
This isn't completely unreasonable because the subjects have access to more
information about their own health than do the researchers.

~~~
tgb
Agreed though the previous study had an intervention and so more directly
supported the idea that the belief created benefits.

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your-nanny
>a representative sample estimated to reflect over 475 million US adults.

Thems some odd numbers

~~~
your-nanny
The number exceeds total us population. However if it's a count over time with
entry if new persons into popukatiob then possible

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danschumann
The brain has pretty direct contact to all the cells of the body. Regardless
of overall activity, if the brain has an idea in mind, it can make it happen.

There's a tribe in Africa that comes to mind. They studied them, because they
don't eat that much and they do a ton of activity. It turns out, when they
run, they just burn fewer calories than most people. So, intake, calories
burned, overall health, it all seems to not follow a hard and fast rule, apart
from the intention of the mind.

Ignore politics for a second, the amount of time he spent on his feet and the
amount of energy it must have required during the campaign, and how Trump's
doctors say he's really healthy(assuming you believe them), but his diet looks
pretty bad, but you know in his head, he's saying, "I'm the healthiest, I'm so
healthy, my health is great, it's the best".

Take-away from article? "I'm so healthy, I'm the healthiest, my health is
huge, it's the best."

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ordinaryperson
Yes mindset is important. But having run 8 marathons I can tell you wishful
thinking is not a substitute for training.

You can’t really quantify fitness, there are too many subtypes (running?
swimming? weightlifting?) This study used blood pressure and weight (among
others) but those can vary wildly based on genetics and diet, I’m not sure
they’re reliable indicators.

The point of the article (as I understand it) is that positive thinking can
influence your health. Fine. But let’s not get carried away: you’re not going
to roll out of bed and complete an Ironman without training just because you
think you can.

EDIT: Mods have updated the title to better reflect the first underlying study
(which focuses on mortality, not fitness).

But 1) even with the focus on mortality, it's still hard to correlate PMA and
mortality and not control for diet, exercise, history, genetics, etc. and 2)
if PMA doesn't correlate w/fitness, it's hard to see how it can make you live
longer (i.e., can you be morbidly obese and positive and live longer than an
athlete with a bad mental attitude?)

PMA is good. But I'm having a hard time believing you're going to live longer
-- seems like there are 50 other factors that are more important.

~~~
wodenokoto
I thought capacity for taking in oxygen[1] was a general indicator of fitness.
But then again, I haven't looked into this since highschool 15+ years ago.

[1]
[https://en.wikipedia.org/wiki/VO2_max](https://en.wikipedia.org/wiki/VO2_max)

~~~
ordinaryperson
What about powerlifters or weightlifters? Super strong. Get winded walking up
a flight of stairs.

My point is, there is no one universal definition of fitness.

The most reliable measure I've heard of is belly fat, which you can measure
with a calipers. But you can't wish away belly fat with positive thinking, so
I think the writers of this article are taking this study a little too far,
IMO.

~~~
SketchySeaBeast
Belly fat would be a poor measurement of a lot of powerlifters fitness as
well.

The article seems to be mixing up "fitness" and "chance of death", which,
while they are related, are probably not as directly correlated as they seem
to be in the article.

~~~
ordinaryperson
Yes, the article seems to take liberties from the two studies it quotes.

But I also am skeptical of the underlying studies. So many factors in
mortality rate I'm having a hard time believing they were able to control for
all of those (weight, age, diet, exercise, family history, etc) and isolate
"positive thinking."

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neuro_imager
I can't believe this waffle qualifies for a Harvard medical school
publication. Clearly the wooly-haired management and soft science types have
overrun Ivy League Medicine.

~~~
dang
This comment breaks the site guidelines, which ask: "Please don't post shallow
dismissals, especially of other people's work. A good critical comment teaches
us something." So could you please not post like this here?

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

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matte_black
You need to be logging at least 150 workout days a year to be considered fit.

~~~
inertiatic
I workout less than 100 hours a year in 1 hour sessions and I'd consider
myself pretty fit. My peers and any physicians I've visited also agree.

I have to ask, by whose standard?

