
Why Exercise Makes You Less Anxious - tokenadult
http://well.blogs.nytimes.com/2009/11/18/phys-ed-why-exercise-makes-you-less-anxious/
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Alex3917
Would driving a race car or something like that for 20 minutes a day give some
of the same benefits as actually exercising?

I have this theory that anxiety and depression are most commonly caused by
sensory deprivation, which is obviously counter-intuitive, but it seems to
match with both the clinical data and also with anecdotal evidence about how
people self-medicate.

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dunstad
In terms of sensory deprivation tanks, Wikipedia says that it actually can
relax you in the short term, and only causes anxiety after prolonged exposure
(or lack thereof).

<http://en.wikipedia.org/wiki/Sensory_deprivation>

~~~
Alex3917
To explain my theory, basically I propose that the brain has two parts: the
part that processes thoughts and patterns, and the part that processes
incoming sensory data. With depression, information coming from the thought
processing part of the brain becomes more salient, and the information coming
from the sensory perception part of the brain becomes less salient. And
basically the way to fix depression is by stimulating your sensory system with
the right amount and type of sensory stimulation at the right time.

More specifically, my proposed mechanism is that during a state of depression,
outside stimuli don't get processed properly because they are more than the
brain can handle, thus you are essentially suffering from the effects of mild
sensory deprivation even though you are surrounded by a normal amount of
stimuli. And the way to fix this is by starting with less stimulation and then
layering more stimuli on top so that you can 'jumpstart' the brain, so that it
goes back to being able to normally process the level of incoming stimuli in
the outside environment.

Note that this doesn't contradict any of the established ideas about serotonin
deficiency, and I'm not at all recommending forgoing the traditional
treatments.

My thinking is that the reason SNRIs and traditional treatments work is
because they either involve stimulating the sensory processing part of the
brain, or else (with CBT) they help people to avoid triggering excessive
rumination.

What's the data? Look at both the recommended treatments and also the ways
people self-medicate: there is listening to classical music, wearing more
cologne, cuddling with someone else, cutting themselves, TMS/ECT, SSRI/SNRIs,
acupuncture, exercise, increasing social contact, etc.

All of these are activities that increase the activity in the sensory
perception part of the brain, so my thinking is that you can purposely
increase the activity in this part of the brain by applying the right stimuli
at the right time, and thus ultimately fix the problem by bringing your
sensory perceptions back to the proper salience.

Anyway I was doing a little reading on depression a month ago on behalf of a
couple friends, and this is just sort of a pattern I picked up. Not sure what
to make of it, but I think it holds and is also very easy to test empirically,
although I'm not a scientist so take it cum grano salis. Obviously there are
purely biological or nutritional causes as well, but based on the extremely
high efficacy of non-drug treatments it seems like there is something similar
to what I'm describing going on.

~~~
joeyo
I like your theory. However, an alternative hypothesis within your framework
could be that depression is a disorder where internal thoughts are
_overrepresented_ rather than external sensory experiences underrepresented.
It seems like this could also result in the same coping behaviors eg cutting.

I wonder if a way to test these hypotheses would be to consider situations
involving the expectation of a sensory experience and look for a mismatch
between that and the actual sensation. You could do this with the rubber hand
illusion or immersion in a virtual reality environment. A depressed person
would putatively have an abnormal congruence between the magnitude of their
internally generated brain states and external sensation.

~~~
Alex3917
"an alternative hypothesis within your framework could be that depression is a
disorder where internal thoughts are overrepresented rather than external
sensory experiences underrepresented."

I think both are happening. Basically internal thought processes increase to
an unhealthy degree as a way of compensating for the decrease in sensory
perception, which is the same thing as happens in a sensory deprivation tank.

I think the initial cause of the depression can be either not enough sensory
stimulation or too much thinking, as happens when there is a traumatic or very
stressful event. If the latter is the root cause then you may need CBT or
meditation or something like that. But in both cases using my sensory
jumpstart method would work to fix a bout of depression, although it will keep
recurring until you change your lifestyle (sensory as root cause case) or come
to terms with whatever is stressing you, or at least learn to avoid the
negative thought triggers.

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tjsnyder
Exercise does seem to steady my emotions, but that's not the greatest benefit
I get from exercising. Health benefits aside, I can simply focus more. There's
nothing like being able to sit down and fully comprehend the problem at hand
because you went for a run earlier.

~~~
scott_s
I think increased ability to focus and steady emotions are basically the same
thing.

~~~
jamesbritt
Not so for me.

Also, exercise doesn't seem to improve my ability to focus, though I've not
tried controlling for other things (sleep, stimulants, etc.). Could be my
focus would be worse were I not exercising regularly.

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uuilly
It seems like an odd test to me. Swimming in cold water would test fitness
more than ability to handle stress. And since some rats did not exercise they
became less fit and would not handle the cold water test as well. Am I missing
something?

~~~
gcheong
My guess is that they didn't push them beyond the level where fitness
mattered. Sort of like having a group of people run a couple of laps around a
track - which even sedentary people could probably manage without much stress
on their bodies. In the article it was stated that rats do not like swimming
in cold water and so they are apparently testing the affects of that kind of
stress rather than just the stress of physical fitness.

~~~
fauigerzigerk
I'm not sure how they can separate stress caused by fear from stress caused by
the physical challenge alone. I don't think this is a good experiment.

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petercooper
A recent Ask HN seemed to reveal there are a lot of people here with bipolar
disorder (or bipolar tendencies, at least). For those of you who are bipolar,
have you found exercise to be a cure-all or to work in combo with
lithium/medication, or...? Basically looking for anecdotal advice here. (FWIW,
I have bipolar II.)

This article just reminded me I wanted to raise the question here, but I don't
think it warrants its own post.

~~~
San
For me, the most important thing is to stick to my daily schedule. Every
single day of the week.

Once I skip one or two meals, work long hours, or stay up late, my life starts
spiraling out of control. So I live on a fixed schedule now, which includes
three hours of exercise per day:

* One hour of swimming at 7AM; this forces me to get out of bed on time, and makes me hungry for breakfast.

* One hour of rowing at 5PM; this forces me to stop working, and makes me hungry for dinner.

* One hour of running at 11PM; this forces me to stop whatever I am doing that evening, and gets me tired for bed.

(In addition I have hundreds of small rules: never go shopping alone, the bed
is only for sex and sleeping, dinner must take at least fifteen minutes to
prepare, ...)

It does take a lot of time and self discipline (and monitoring by others), but
it sure helps me to keep my life under control.

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WilliamLP
The problem is that there are some really fundamental differences between rats
and humans in terms of metabolism. (E.g. things as different as that they have
a type of muscle fibre, type IIb, that we do not have at all.)

You just can't take studies on rats like this and assume that they have any
relevance to humans. There are many many known metabolic effects that work on
rats but not on people.

~~~
tokenadult
In human subjects, I would wonder if exercise outdoors in sunlight is more
efficacious for reducing anxiety and stabilizing mood than exercise with
indoor lighting. I also wonder if exercising with a friend is better than
exercising alone for Homo sapiens. All I've got on this issue from personal
experience are anecdotes,

<http://norvig.com/experiment-design.html>

but I would be interested to see if there are human-specific effects that
wouldn't generalize back to other animals.

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joe_the_user
Hmm,

The reasoning involved in the experiment seems rather tenuous to me.

if we tried to under a computer only by how many 0's it wrote to memory for a
given input, our understanding would be rather limit.

If a brain is highly tuned and complex thing, our ability to read the meaning
of certain things firing or not firing for certain events is going to be
limited.

The thing is the real progress is being made in far more detailed approaches
than this - simulating whole fly brains or large parts of a cat brain. I
suspect that this is where any real understanding is going to come from.

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leecho0
So the rats were more stressed out from cold water than getting killed and
getting their brains examined? interesting.

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anonjon
I always assumed that this was because my brain is part of my body, and doing
stuff that is good for my body would be the same stuff that is good for my
brain.

For some reason we draw this weird metaphysical distinction between the brain
and the other organs in the body that make results like this seem strange,
when they clearly are not.

The idea that healthy people think better should not shock us. (Think better
in terms of lower incidence psychological problems, although i always feel
smarter after I exercise as well...)

