
Does exercise slow the aging process? - tmbsundar
http://well.blogs.nytimes.com/2015/10/28/does-exercise-slow-the-aging-process/?_r=1
======
jacquesm
I don't know if it will actually slow down aging (which is a very wide
concept). But I do have a 'proof of 1' that cycling a lot will wear out your
knees and hips prematurely.

Bodies are like machines, if you use them a lot they will wear out because of
over-use. If you use them very little they will atrophy.

The balance is probably somewhere in the middle, yes, exercise but don't
overdo it.

~~~
riggins
_Bodies are like machines, if you use them a lot they will wear out because of
over-use._

This is a poor analogy. Bodies can heal (i.e. regenerate tissue). Machines
cannot. If this analogy was true, ultra-marathoners would be wearing out their
joints rapidly. That's not what is being observed though.

What is true is that you can injure joints by increasing the workload too
fast. Joints can strengthen and adapt to increased loads but it happens
slowly. So don't go from running 5 miles per outing to running 10 miles. Limit
yourself to a gradual increase.

[http://journals.plos.org/plosone/article?id=10.1371/journal....](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0083867)

[http://content.time.com/time/health/article/0,8599,1948208,0...](http://content.time.com/time/health/article/0,8599,1948208,00.html)

~~~
Udo
There is no question that bodies _are_ in fact machines, there are parts that
regenerate and parts that don't. Many extreme sport enthusiasts carry life-
long consequences of parts they broke during their activities.

The issue here is more if the oxidative stress put on your components is
offset or even completely overshadowed by the biochemical benefits of
exercise, and there is indeed reason to believe that a moderate exercise
regime - not unsurprisingly - may yield optimal results.

Exercise too little and your body's machinery will start to suffer from use-
it-or-lose-it symptoms. Exercise too much and you will cause an inordinate
amount of mechanical wear that cannot be regenerated, plus there may be some
biochemical stresses as well.

I know "do it in moderation" makes for a shitty headline that interests
nobody, but all things being equal that should probably be the take-away here.
I agree with you about gradual increase being advisable, but perpetually
aiming for your physical limits may not be the most appropriate course of
action for individuals who are already fit.

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jasode
And to add to the confusion, you have another study considering the opposite
conclusion. The study explored the effects of exercise increasing free
radicals and advanced aging.

[http://www.ncbi.nlm.nih.gov/pubmed/9177582](http://www.ncbi.nlm.nih.gov/pubmed/9177582)

~~~
outlace
This study sort of makes an assumption that increased free radicals causes (at
least in part) aging (free radical theory of aging). The relationship between
radical oxygen species (free radicals) and aging is not at all clear to my
understanding. (this paper is from 1997)

Moreover, it's possible that the tissues most susceptible to oxidative stress
during exercise (i.e. muscle) are also most adapted to handle it. So overall,
yes ROS increase but mostly just in muscle where it is well-adapted to handle
it, and the benefits of exercise (lowering blood pressure, better circulation,
etc) trump any detriments of increased ROS.

Edit: Found this review [
[http://www.ncbi.nlm.nih.gov/pubmed/23434764](http://www.ncbi.nlm.nih.gov/pubmed/23434764)
] that considers evidence that ROS may actually be a part of a pro-survival
signal cascade

------
calebm
My wife and I are reading this book called "Move Your DNA" (by Katy Bowman).
She has an interesting thesis: modern exercise is "junk movement" (like "junk"
food). The idea is that humans were meant to move more throughout the day, and
that trying to cram all of our needed movement into a small 45-minute block is
similar to how junk food crams tons of calories into a small bit of food.

We're not finished with it yet, but initially, I find it interesting.

~~~
dghughes
Then you have studies showing High Intensity Training (HIT) where you only
exercise three minutes per week is beneficial. But it may depend on your
genes.

[http://www.bbc.com/news/health-17177251](http://www.bbc.com/news/health-17177251)

>The idea is that humans were meant to move more throughout the day

My parents are always on the go gardening, going to auctions, walking a bit,
always doing something. Dad eats a lot but eats everything fish, shellfish,
many kinds of meat, all kinds of vegetables he gets a huge variety of food.

I'm sitting watching my computer screen not moving, I eat a limited diet and I
think I will be worse off than my parents. And I think Millennials will be
even worse I've never seen so many fat people at such a young age, at least
bottom out at mid 40s and not mid teens.

------
KerrickStaley
This is an observational study and proves correlation, not causation. People
whose bodies age slowly for whatever reason are more likely to be athletic,
especially in the 40-65 age range they called out.

------
repsilat
> _this study is purely associational, so cannot show whether exercise
> actually causes changes in telomere length, only that people who exercise
> have longer telomeres._

> ...

> _So the message seems clear, he says. “Exercise is good” for your cells, and
> “more exercise in greater variety” is likely to be even better._

Fascinating -- the first quoted sentence is logically equivalent to saying,
"If you have short telomeres you're statistically unlikely to exercise much."

The conclusion that exercise leads to shorter telomeres is empowering and
optimistic, so it's no surprised the American scientists and press ran with
it. The conclusion that people who exercise regularly are genetically
predisposed to it is _disempowering_ , though, and it wasn't mentioned at all.
(It is consistent with jasode's sibling comment that exercise can speed up the
ageing process, though.)

I'd also be interested in the inverse correlation -- are sedentary lifestyles
associated with shorter telomeres? What proportion of people in the study
actually did exercise, and what proportion had shorter telomeres? Essentially,
"show me the numbers in all of the boxes and let me draw my own conclusions."

------
5555624
Previous comments:
[https://news.ycombinator.com/item?id=10468025](https://news.ycombinator.com/item?id=10468025)

------
isolate
Personally, I think the question of the effect exercise has on my lifespan is
irrelevant.

A lot of people talk about exercise being valuable because it makes you
healthy. I like all the wonderful benefits of being healthy and in good shape,
yes, but I also genuinely like exercise. There is basically nothing as
incredible as the right kind of physical exertion for me.

If exercise is a vice, who cares? It's worth it.

~~~
CuriouslyC
Right on. For me, exercise provides a very convenient way of challenging
myself. The fact that I look fantastic and I'm very fit are really cool side
effects.

------
csvan
"Sitting is the new smoking"

~~~
abhi152
very true.

~~~
djhn
Except that it isn't. It would take a lot of obviously sitting-related deaths
for it to warrant comparison to smaking. Stress may be the new smoking, but
sitting is definitely not.

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reasonattlm
The most interesting result from recent research into exercise is this:

[http://www.alphagalileo.org/ViewItem.aspx?ItemId=159410&Cult...](http://www.alphagalileo.org/ViewItem.aspx?ItemId=159410&CultureCode=en)

[http://dx.doi.org/10.1038/srep18259](http://dx.doi.org/10.1038/srep18259)

An open access paper on exercise in identical and non-identical twin pairs was
recently published, the data suggesting that long-term differences in physical
activity between identical twins don't result in any significant difference in
longevity, even though other differences in health outcomes are observed. We
might draw parallels between this and similar results observed in a mouse
study from a few years back, in which the exercising mice had better health
but no increase in maximum life span. The researchers here theorize that the
well-known epidemiological association between exercise and increased life
expectancy is perhaps as much a matter of genetics as of choice.

For any observed statistical relationship in humans there are always questions
of causation. This is especially true in the web of associations related to
aging and mortality in population data, in which life expectancy, wealth,
social status, intelligence, education, exercise, diet, and culture all have
ties to one another. That we pay great attention to these relationships is a
function of having no good way to treat aging, I've long thought: we care
about trivial differences in life expectancy of a few years here and a few
years there because this is all that is in our power to change right now, and
that will continue until the development of rejuvenation therapies. Life
expectancy and exercise are linked robustly in many data sets, and even more
so now that accelerometers are so cheap and ubiquitous that even large studies
can use them to obtain actual rather than self-reported data on physical
activity. There are studies to demonstrate longer life expectancy in athletes,
longer life expectancy in those who exercise modestly versus those who are
sedentary, and so forth. What are these studies measuring, however? For
example, what if people who are more robust and would live longer regardless
of exercise tend to exercise more? Or perhaps exercise levels are a good proxy
for lower levels of visceral fat tissue and consequent chronic inflammation -
themselves linked to greater risk of age-related disease and mortality.

The results of this study definitely muddy the waters in the search for
causation and mechanism in exercise and mortality reduction, providing
evidence to support a state of considerable complexity in the relationship
between exercise, genetics, and outcomes in health. Nothing in biology is ever
as simple as we'd like it to be, so this should perhaps be expected.
Regardless he data presented below should be added to the many past studies on
exercise and mortality, and its weight balanced accordingly - never take any
single set of data and interpretations as gospel in science. This doesn't
change the consensus, which is that you should exercise, and that you are
expected to obtain benefits by doing so. It does add subtlety to the picture,
however.

------
dschiptsov
Circulation. The difference is like between a rainforest and semi-desert.
Efficient regeneration of tissues.

Of course other factors matter. Air quality, variety of foods, water sources,
sleep patterns, noise, stress, ecology in general.

There is nothing new about these notions - actively working peasants in
unspoiled remote areas are champions of longevity.

------
l1feh4ck
Whether that study is true or not 'do exercises' at least you can have a
healthy and fit body in your available life span.

------
jasonmp85
I think the operative question is does it slow down aging at a rate faster
than the time you spend exercising?

~~~
tajen
A precedent study showed that 1hr of sports increased your life by 8hrs. 1hr
very intensive sports increases it by 16hrs, 1hr of walking increases it by
2-4hrs. The study concluded on the fact that it probably only works up to
7-10hrs per week, as that's the level which makes injury more probable. They
say "probably" because injury doesn't shorten the lifespan, it only makes in
uncomfortable. Which is probably what you want: Longest comfortable life,
followed by rapid descent.

------
furfish
According to the law of headlines the answer is "no".

------
nikolay
Aerobic exercise actually speeds it up due to increased oxidation in the
system, but, in general, any BMR (Basal Metabolic Rate) increase also speeds
up your demise, but this is in the ideal situation where we all die naturally,
not from chronic disease, cancer, etc. Why? Because our cells can't divide
indefinitely (Hayflick limit [0]). Any activity that increases growth factors
also can speed up cancerous growth. So, don't run, don't exercise - just walk,
do gardening work, and other normal human activities.

[0]:
[https://en.wikipedia.org/wiki/Hayflick_limit](https://en.wikipedia.org/wiki/Hayflick_limit)

~~~
nikolay
All gym-goers and runners gang up and downvote me... but this won't change
what I said. Read up, educate yourself, research other species, and you'll
find the truth.

And let me be even more direct: you're endorphins junkies!

~~~
enraged_camel
You're being downvoted because your reasoning is pure nonsense. Yes, cells can
divide only a limited number of times. And then they die. But guess what: your
body is capable of creating new cells. This is in fact what happens when you
lift weights: new muscle tissue is generated.

~~~
avz
> Yes, cells can divide only a limited number of times. And then they die. But
> guess what: your body is capable of creating new cells.

If I read this correctly, you imply that "creating new cells" is somehow an
alternative to cell division. This isn't true - cell division is in fact the
only mechanism by which new cells normally(1) come to life.

Consequently if the GP was correct in general in saying that cells can divide
only a limited number of times then yes, eventually the organism would lose
the ability to regenerate and die. The reality is that not all cells have a
limit on the number of divisions. Majority of differentiated cells do, but a
few special types of cells have no such limit. These are called stem cells.
Many tissues have stems cells on standby waiting for signals that trigger
regeneration. Cancer cells often break out of the limit, too (2).

Telomeres provide a mechanism that limits the number of cell divisions - they
get shortened on each division and once they become too short the cell loses
the ability to divide further. Stems cells (and some cancer cells) express an
enzyme called telomerase (3) that extends the telomeres to their original
length after cell division.

(1) Reproductive cells (sperms and ovums) can also create a new cell by
merging, but this isn't relevant for somatic cells.

(2) Cancer is a neat demonstration of the dangers that uncontrolled cell
division poses for a complex organism and explains why most types of cells
have their division machinery restricted or disabled.

(3)
[https://en.wikipedia.org/wiki/Telomerase](https://en.wikipedia.org/wiki/Telomerase)

~~~
nikolay
Boosting telomerase is a double-edged sword - it can make cancer bloom, too,
and we all have some cancerous cells in us.

------
kingsley3
Hi,

I maintain the world's biggest spread sheet of life span experiments.

I believe slowing aging can increase life span.

It turns out that the effect of exercise on all-cause mortality is well
studied.

My big spread sheet summarizes about 80 experiments.

They show that exercise usually lets us live longer.

A histogram of their results is at

    
    
        http://morse.kiwi.nz/kingsley/lib/exe/fetch.php?cache=&media=science:histogram_of_exercise_vs_all_cause_mortality.png
    

I think the trick is to not OVER train.

I'm told that over-training is worse than no training, and just working up a
light sweat is good.

More findings from data mining my big spread sheet of life span experiments
are at

    
    
        http://morse.kiwi.nz/kingsley/doku.php?id=science:kingsleys_big_spread_sheet_of_life_span_experiments

------
kingsley3
Hi,

I maintain the world's biggest spread sheet of life span experiments.

I believe slowing aging can increase life span.

It turns out that the effect of exercise on all-cause mortality is well
studied.

My big spread sheet summarizes about 80 exercise experiments.

They show that exercise usually lets us live longer.

A histogram of their results is at

    
    
        http://morse.kiwi.nz/kingsley/lib/exe/fetch.php?cache=&media=science:histogram_of_exercise_vs_all_cause_mortality.png
    

I think the trick is to not OVER train.

I'm told that over-training is worse than no training, and just working up a
light sweat is good.

More findings from data mining my big spread sheet of life span experiments
are at

    
    
        http://morse.kiwi.nz/kingsley/doku.php?id=science:kingsleys_big_spread_sheet_of_life_span_experiments
    

Thanks, Kingsley

------
amelius
Perhaps cardio training. But bodybuilding will probably not slow down aging; I
suppose it wears one down physically, and also imposes a huge load on the
central nervous system. It would be nice to have a scientific study on this,
to see to what extent this is true.

