
The Right Dose of Exercise for a Longer Life - prostoalex
http://well.blogs.nytimes.com/2015/04/15/the-right-dose-of-exercise-for-a-longer-life/?smid=fb-nytimes&smtyp=cur&bicmp=AD&bicmlukp=WT.mc_id&bicmst=1409232722000&bicmet=1419773522000&_r=0
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nidieunimaitre
I always wonder to what degree this kind of study might invert causality: that
is, people who are subclinically "ill" may be less likely to exercise in the
first place because it is harder or less pleasant for them. Someone with, for
example, undiagnosed but significant cardiovascular disease (unfortunately
very common: in many cases the first sign anyone recognizes as concerning is a
heart attack) is likely to have some degree of decreased exercise tolerance
and discomfort at longer durations and intensities -- and thus will be less
likely to meet the recommendations.

~~~
brlewis
You're not the first to wonder about this.
[http://www.ncbi.nlm.nih.gov/books/NBK62370/](http://www.ncbi.nlm.nih.gov/books/NBK62370/)
"It should be noted that while these results may reflect the effect of
exercise patterns on mortality, reverse causation is also possible—that the
results reflect instead the effect of health on physical activity."

But what if you studied people who made a decision to change their exercise
habits, and checked if it made a difference in general health?

~~~
dragonwriter
That would seem to be subject to the same basic problem; whether people make a
decision to add exercise may well be strongly affected by their experience
with activity eighth may be affected by the same kind of subclinical condition
that itself is a mortality predictor discussed up thread.

Of course the potential for such inverted causality is a cause for developing
and testing hypotheses about the alternative explanations, not a reason to
casually dismiss the study or the more obvious conclusion on the causal
relationship.

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suprgeek
A very important detail - these are survey studies: "Of course, these studies
relied on people’s shaky recall of exercise habits and were not randomized
experiments, so can’t prove that any exercise dose caused changes in mortality
risk, only that exercise and death risks were associated."

NOT Randomized controlled trials.

So take these with a pinch of salt and then go outside & run for 30 mins every
day.

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bhaumik
>The sweet spot for exercise benefits, however, came among those who tripled
the recommended level of exercise, working out moderately, mostly by walking,
for 450 minutes per week, or a little more than an hour per day. Those people
were 39 percent less likely to die prematurely than people who never
exercised.

~~~
griffinmahon
This is like that one TED talk on longevity that found green zones where
people lived much longer. One factor found in these people's lives was an
ambulatory day, just generally walking a lot -- but, surprisingly, none of
these groups went out of their way to exercise.

~~~
IndianAstronaut
I wonder if we integrated regular walking into our city planning that we could
reduce cardiovascular disease and obesity.

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tempestn
Now we need someone to combine these two to give us a picture the whole
parameter space. Wouldn't a 3d graph by awesome here? Premature death rate on
the Z axis, minutes of weekly exercise and percentage that is beyond a given
intensity threshold on the X and Y? You could then compare that to the same
thing, except using average intensity as the metric instead of amount of time
spent over a threshold.

450 minutes per week was optimal when it was mostly light exercise, and
intense exercise is more beneficial, with diminishing returns after 30 minutes
per week. But if you do a higher percentage of intense exercise, does the
optimal time per week decrease? (Or maybe even increase as you get beyond a
certain fitness threshold! Although I somewhat doubt that.)

~~~
niels_olson
Reading the abstracts, the measurement the US study uses for "dosing" is
metabolic-equivalent hours per week. The Australian study uses "vigorous".

If you want to grade your activities of choice to METs, there are various
sources to do estimate them:

[http://en.wikipedia.org/wiki/Metabolic_equivalent](http://en.wikipedia.org/wiki/Metabolic_equivalent)

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31reasons
Studies like these always make me think how little we know about human body. I
wonder when are we going to stop doing these kind of studies and learn from
human body as purely engineering system. By simulating it at a molecular level
and understanding it that way.

Where are the chips that mimic cells and help create complete simulation of a
trillion+ cell system? We need Elon Musk of human body :)

~~~
melling
How about simply being able to better monitor/measure changes in the body?

~~~
31reasons
Changes of what? There are millions of parameters that affect each other in a
nonlinear fashion due to genetics, environment, diet etc. Getting such data
from the living system would be prohibitively invasive, blood tests have their
limitations and doesn't provide real-time data.

~~~
melling
I don't know what can be or should be measured. The idea is to develop better
techniques for monitoring the body. A future tricorder X-Prize, for instance:
[http://tricorder.xprize.org](http://tricorder.xprize.org)

You're telling me what we can do today. I'm asking what we can develop to
solve the problem.

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borgia
I'm glad we're getting a better understanding of how much these variables
contribute toward longevity and well-being. Now we just have to come up with a
plan to deal with the challenges of people living far longer.

I don't know if I'm alone in noticing this, but there appears to be a larger
divide in society along these lines opening up. More people seem to be
exercising than ever - almost every guy I know has a gym membership, is taking
part in a sport, or goes hiking, or whatever - where previously the same
people may have been thin/healthy but sedentary.

On the other side of things, it appears that more people seem to be simply
getting _more_ fat and more sedentary. Where once there was thin/average and
sedentary | mildly overweight and sedentary, it seems to be dividing to
thin/average and pretty active | very fat and very sedentary.

That is all from personal observations, but it will be interesting to see the
physical composition of society in 5-10 years time. What was once overweight
has simply become normal, what was "fat" has now become huge and what was once
a healthy weight has become the new thin.

~~~
nileshtrivedi
> More people seem to be exercising than ever - almost every guy I know has a
> gym membership, is taking part in a sport, or goes hiking, or whatever -
> where previously the same people may have been thin/healthy but sedentary.

That's because more of our interactions are moving online than offline so you
see people at their best and not how they typically are. ;-)

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flambard
When this subject comes up, I always think of this article:
[http://startingstrength.com/articles/barbell_medicine_sulliv...](http://startingstrength.com/articles/barbell_medicine_sullivan.pdf)

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benihana
For me it always comes back to: what are people's long, long term goals.
Overall? Is it a longer life? Do you want to live an extra five years? I
personally don't think that's a good goal. I'd much rather be in good shape,
mobile, healthy and relatively pain free for my 30s, 40s, 50s, 60s and as far
into my 70s as I can manage than to increase my lifespan from 85-90.

It's way less about eking out a few more years of keeping death at bay and way
more about feeling good while I'm a mobile, mentally healthy adult.

~~~
nostromo
Young people say this a lot, but I don't hear people in their 80s say it.

When my grandpa was dying in his mid-80s, it really hit home for me how scary
it is. Even if you've had a fulfilling, long life, dying still sucks. For
young people, another year of life for an 80 year old doesn't seem like much,
but to an 80 year old it means the world.

~~~
dspillett
_> Young people say this a lot, but I don't hear people in their 80s say it._

When you are young those five years don't look that attractive: you are older,
slower, half your friends and family are gone, you might not have any money to
support the life you want depending how the economy goes, and so forth - so
having a bit more fun _now_ seems like a good compromise. Once you get older
then you realise that any time is worth having as there are still more things
you want to do and more time you want to spend with people than you might have
time for left.

Of course having too much "fun" now means that your old decrepit years come
sooner because your body will fall apart faster, so that really isn't the good
compromise is might seem to some - you start paying in good years as well as
the later ones you might be dreading at this point in your life.

To be far far more flippant about it, my reasoning up to a few years ago was:

 _" My main worry is being able to afford to live a content life beyond a
certain point so my current pension plan is to not live long enough to need a
good pension. Hence my drinking habit: I'm investing heavily in cirrhosis
futures!"_

Having started to see some of my older friends in bad conditions, various
people in my life having less serious but still significant health scares, I
changed my mind about that quite a bit. Had I not decided to shape up back
then, an old friend my own age (mid 30s) shuffle off to the crematorium rather
prematurely recently might have made me do it. I might not care about those
last few years in my 80s now, but I certainly care about hanging around for a
good few years yet. I've got places to see and people to do!

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ChrisNorstrom
I think a lack of exersize throughout the day is why guys today are going bald
earlier than in previous generations. I think high intensity exercises for 3
min every 1-2 hours throughout the day is reversing my hair loss. I'll be
making a blog post on it soon with evidence of my progress.

Since August of 2014 I had been losing my hair. More and more of it was
showing up in the sink drain. Earlier this year I got worried because it
increased. I wasn't sure if it was a temporary thing due to stress or illness
so I started saving up the little clumps of hair between paper towels and date
stamping them. It just kept getting worse and worse. I got a blood test to
check hormone levels and find out if everything's ok. I'm waiting on the
results.

Last month I got tired of it all, and decided to experiment as a last ditch
effort to prevent baldness in my late 20s. I started short but high intensity
exersizes every 1 hour, for about 2-3 minutes. After only 1 week new hair has
started sprouting up on my scalp. And the amount I've seen in the sink drain
has gone down drastically. This is very odd because there's a huge delay in
when hair grows and falls (often months) not 1 week. So I'm convinced it's the
exersize that's increased circulation, jump started cell growth, and
maintained healthy hormone levels. I need to test this out in the long term
and try to get other guys to participate. I doubt it's a coincidence because 1
week I skipped my exercises and my hair growth decreased a bit and hair loss
increased a tiny bit.

tl;dr The right dose of exersize for a healthy head of hair. Possibly.

~~~
BSousa
I started losing mine at 17 and I worked out/moved a lot at the time (played 2
sports + fun activities) so I doubt there is a connection there.

~~~
ghthor
Male pattern baldness is directly linked to testosterone. I believe is also
linked to stress. If you're TOO active and causing high levels of cortisol in
your system then you'll probably go bald early.

