Why Exercise Makes You Less Anxious | Hacker News Reader

Why Exercise Makes You Less Anxious

well.blogs.nytimes.com

91 pointstokenadult24 comments

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.

Interesting idea! I wonder if that's why I always feel so much more awake and focused after taking a shower?

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

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.

Sounds commonsensical since my mom always said things like "you're depressed because you're just sitting there, go outside more!" And she was usually right. But..I know a bunch of busy workaholics who are pretty depressed, if you go by alcoholism and self-hatred. And when you say "the right amount and type of sensory stimulation at the right time" it sounds like you're just saying "the cure for depression is to find something to do that'll cure your depression," unless you've got a sharper idea of what you mean.

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.

"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.

A common catchphrase amongst some of my motorcycling friends is "You never see a bike parked outside a psychiatrist's office..."

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.

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

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.

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?

Yeah this is totally what I was thinking?!?!

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.

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.

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.

My hypothesis is that exercise-as-such helps with mood disorders, exercise outdoors (to regulate circadian rhythms) helps more, and exercise with someone else (to have pleasant social interaction and a reality check on one's thinking during conversation) helps still more. I wouldn't recommend NOT taking standard medications--I've seen a lot of people get a lot of help from lithium, but lithium leads to weight gain for many people, so then the exercise becomes all the more necessary.

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.

I don't have bipolar disorder, but I do know on particularly stressful days that the best thing exercise does is get you out of your own head - so the only thing you can possibly do is focus on is moving faster, pushing that weight harder, swimming faster, etc.

Personally, if I'm exercising and can keep an internal thought dialogue, I'm not exercising hard enough. Then again, I've been a runner all my life, and we runners take great pleasure in feeling pain and finding that point where we just can't mentally take it anymore.

Bottom line though, exercise is bar none the single best thing you can do for personal health and sanity (after a good night's rest of course)

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.

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.

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.

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

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...)

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