An Unexpected Effect of Ultra-Marathons: Temporary Brain Shrinkage | Hacker News Reader

An Unexpected Effect of Ultra-Marathons: Temporary Brain Shrinkage

smithsonianmag.com

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It's a pity they didn't normalize/baseline for dehydration, which has been demonstrated to result in brain shrinkage: http://campus.neurochirurgie.fr/IMG/pdf/changement_volume_ce...

I'd love to do the same study on an 8 hour day of meetings and compare to an extended period of uninterrupted coding.

Goodness. There are ultra-marathons, and then there are trans-continental ultra-marathons. I have a friend who did a number of 50s, at least one 100 (I was there to watch), and I think a Canada to NYC run. Her brain seems to fine as she approaches 60, but her knees aren't up to long distances.

(Full disclosure: I ran a few times over 26.2, only once as far as 50.)

"as she approaches 60, but her knees aren't up to long distances."

@cafard, know the feeling. Most of the people I know who ran seriously retired in their 40's, knees smashed. What caught my interest in this article was the quote:

"After about 1,553 miles, the researchers noted that the cartilage that normally cushions joints showed signs of breaking down. But after that point, the runners started building their cartilage again, even without rest. "

What's going on there?

(my disclosure: Keenwalk, 2010 http://seldomlogical.com/2011/MAR/12/keenwalk-why-i-went/ cf Hackernews https://news.ycombinator.com/item?id=1126078 and regular 2000km/yr PT)

I think recent studies don't support the idea that running destroys your knees, actually.

This is correct. The true picture is complex and not fully understood.

Distance running tends to increase surface area of knee cartilage. Lifting weights seems to increase thickness of cartilage.

However, thickness of cartilage seems to have a maximum value beyond which it will not increase. This may be because the chondocytes (cells inside the cartilage that produce and maintain it) gain all their nutrition by diffusion, so cartilage that is too thick would prevent adequate nutrition.

Lack of activity certainly leads to reduction in cartilage thickness, possibly surface area. It is unclear how exercise should be prescribed to optimally restore this.

Irregularities in cartilage surface, due to injury or possibly genetic bad luck, can produce irregular pressure on the underlying bone surface. This seems to be a driving factor in bone changes in early osteoarthritis.

Everyone's response to exercise is unique to them. It's not currently easy to say whether distance running is "good for you". However, the benefits of exercise generally outweigh the risks. Personally I suspect that only a tiny minority of people are capable of regularly running marathon distances and benefiting from that.

If you are over 40, don't expect to do then save intensity or duration of your younger peers, particularly if you are starting a new form of exercise. Your body has already adapted to your lifestyle, and it will be slower to adapt. But find what works for you, do what feels good, don't compare yourself to others, and enjoy yourself.

"But find what works for you, do what feels good, don't compare yourself to others, and enjoy yourself."

That sounds good and right, especially 'don't compare yourself to others'. It is a good Zen training to let others go faster and stick to ones own goals.

It really depends on your stride and general form, doesn't it? It sounds reasonable that overstriding (landing with your foot ahead of the imaginary vertical line passing through your body) would place a lot of pressure on the knee, which would result in long-term damage. The same goes for the landing, it's easier on the body to make good use of the natural mechanism present in the arch of the foot by landing on the mid-foot (ball of the foot).

Daniel Lieberman (Harvard professor) has excellent research on the subject for those interested.

Exactly. Stride and posture are vitally important for a healthy run. As someone with a sprinters build and stride to match any amount of long distance (over 5k) puts a massive strain on my shins. I have a mid foot strike which is quicker over short to mid distances but is completely unsustainable for longer distances (for me at least). Full time running training (5-7 days week) also inevitably results in shin splints. Watching people run in the park it's clear that only ~5% have put any thought into their stride and posture.

This Principals of Natural Running video[0] is pretty good at illustrating foot strike, running stride, posture, mechanics.

[0] https://www.youtube.com/watch?v=1finiZn4G3E

Great video. Thanks

Most women appear to land on the mid foot or even farther forward. Now, women are in general lighter, and who knows how far the random woman runner seen on the streets is actually going? But I know at least one woman with a very forward strike, and who ran a lot, who was still going in her 50s when I last saw her. I don't recall how my friend with the bad knees landed: but I do remember that her way of pushing off at the end of a stride was distinctive, recognizable from a distance.

By the way, have you eliminated the possibility of compartment syndrome?

I believe shin splints is a form of compartment syndrome in the tough sinewy tissue between the tibia and fibula. I had to stop running every day after the last bout. Took 4 months to recover from and by that time all the good work had been undone. I try mix it up more these days with biking and when in better shape also soccer (though that can be terrible for the knees too).

The reason I quit training was because a guy in my track group had the same problem and he didn't quit. It resulted in a badly fractured ankle which took him out for a whole season. I hadn't met him before (I was new to the group) but he turned up to training one day to say hi and told me his story which was a bit of a wake up call. We were training very hard at the time, ~15 hour track time (including warm ups) and ~15 hours weights per week.

I've observed the opposite: the women I see running are generally heel-striking shufflers. But then again, the sample is composed of Parisian women who don't exercise as regularly as they could because of urban conditions and population density (and the resulting scarcity of running estate).

Wait, if they kept walking past the point of damage... cartilage damage would start going away?! Am I reading what you quoted correctly?

"cartilage damage would start going away?"

Running. That's what I quoted from the article. Don't believe it is significant enough though. The citation follows [0] and one study of 44 runners?

[0] Uwe Schütz, M.D (specialist in orthopedics and trauma surgery in the Department of Diagnostic and Interventional Radiology at the University Hospital of Ulm in Germany) Jürgen Machann, M.D., and Christian Billich, M.D. "Imaging Identifies Cartilage Regeneration in Long-Distance Runners" Abstract: https://www2.rsna.org/timssnet/rsna/media/pr2015/schuetz/abs...

and some more explanation:

- https://www2.rsna.org/timssnet/media/pressreleases/pr_target...

- https://www2.rsna.org/timssnet/media/pressreleases/14_pr_tar...

That actually makes a bit of sense to me. Uneducated guess: The cartilage breaks down, releasing some chemical, hormone, or just bits of cartilage into the blood which the body detects at levels above some threshold, prompting the body to begin producing more cartilage.

could be right. (i have no idea about this particular instance but) a whole bunch of our metabolic pathways are initiated/regulated through negative feedback loops like the one you described.

Get her a bike!

I have only recently begun running (18 months) and in that time I have completed multiple halfs, with my first full in January (actually a 2 day: half followed by a full). My goal is to beging doing the 5 day desert ultras.

To date it have been an interest learning experience/experiment.

I used to eat Paleo, without any exercise I was fairly ripped. I dropped Paleo a year ago to incorporate carbs, over the year I have gained 15-20 lbs due to change in diet, while my overall intake has remained about the same. I don't think this is unusual for new distance runner who don't change diets as generally runners will need to increase intake to the point it exceeds what people burn.

Training in tropical weather (Miami) I have run into the issue of heat stroke a few times. This is completely distinct from dehydration and pushes me to train at night.

I developed compartment syndrome and subsequently (thru trial and error) discovered a topical treatment that does not cure but prevents the symptoms. Whereas the only solution that appears anywhere online for this phenomenon is surgery. I would love the opportunity to formally test my topical treatment in an official clinical lab setting.

Diatance running no doubt has odd effects on the body (short term and longe term) but from the just based anecdotally on the hundreds of 60-70 years olds I see in these races who have been running for decades I think it's a good bet overall distance running has a net positive impact on quality of life.

Hi there. Very interested in your topical treatment for compartment syndrome. Frankly, I am very sceptical that (a) it works or (b) you had compartment syndrome. Can you provide further details?

I would simply say this, and if you have CS you should agree, CS is unmistakable. That said there are 2 types I am aware of, CS as a result of accidents/trauma and athletically induced, mine being the later.

(b) Within 30 seconds to 2 minutes of running the pressure/pain begins. Personally I get swelling/bulging in 2 of the compartments to the extent it is clearly visible to the naked eye (this never happened before the CS or when using my topical treatment). In the few instances I "power through" the pain, which I have found mostly impossible, it will lead first to numbness in my feet (though the pain never subsides in the compartments and only increases) and then I develop drop foot during the run. Within ~1 minute of ceasing the run the pain subsides.

(a): I have experimented to the point that I have isolated the CS in 2 out of 4 compartments in each leg. If I don't use the treatment I always have the pain/swelling/pressure. Additionally, through experiments I know I can target one of the compartments in each leg and still have the pain/pressure/swelling in the untreated compartments. Another note, if I apply to topical treatment and don't run within ~1 hour I will develop the pain/swelling/pressure to a lesser degree, but when I go running immediately I have had runs as long as 3 hours and do not experience any symptoms.

My discovery was not random luck, as I experimented with rollers, icing, heating, stretching, shoes, running surface, other topicals, etc... Having found the treatment I don't employ any other variables such as stretching, icing, or heating. It really isn't so crazy to conclude there are topical treatments the body will absorb that could change the fascia viscosity to accommodate muscle expansion.

As I said, I would love the opportunity to go through clinical testing to confirm my treatment works. I am not sure how big the CS market is, but I know that after only 18 months of running I was unwilling to give it up, and surgery is not practical.

Unfortunately this all sounds highly implausible.

If you have found something that you feel works for you, good luck with it. The chances that it works by the methods you suggest are hugely unlikely.

Compartment syndrome can be extremely serious. Extremely. If you notice swelling with numbness or weakness again please go immediately to a hospital.

Good luck! :)

Can you share what the treatment is?

I doubt brain volume shrinkage in itself is alarming - it could well be a physical effect from the shaking or something akin to dehydration (I know the brain is suspended in liquor).

Assessing the cognitive capabilities before and after would be more interesting, but of course much more complicated. Also: 1000+km runs, my god...

> I know the brain is suspended in liquor

eh, a man can dream, but reality be a harsh mistress!

This just in: ultra-marathons are not healthy.

I'm perpetually amazed by the inability of people -- especially Americans -- to distinguish between sport and exercise.

There's a rich body of literature tying high injury rates (unsurprising) and metabolic dysfunction (more surprising) to extreme competitive sports.

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