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Running 50km after 82h of fasting

blog.xavivives.com

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Re: Running 50km after 82h of fasting

#61

Post by tacos »

maxerickson wrote: post #57
tacos wrote: post #52

Earlier quoted context omitted.

> This is a blog post on the author's personal blog No, the context is now reframed as a post on a highly-influential site, this one. The author is now commenting here, which is great. But "Don't try something like this without at least talking to a doctor, I probably should have" has yet to appear on the post. Therefore I reserve the right to state my objection.

Should the talking to a doctor disclaimer come with a disclaimer that you should first make sure your doctor is competent? And a disclaimer to make sure that the person reading the comment is competent to assess whether their doctor is competent? And a disclaimer that there may be errors in the disclaimers, so think for yourself a little bit? Personally, I'll take an article like this one where the author doesn't muc…

You prefer less boilerplate in this situation, I prefer more. I consulted to law firms, perhaps you have not. Mythbusters say "don't try this at home" why can't he?

Re: Running 50km after 82h of fasting

#62

Post by rhinoceraptor »

dpark wrote: post #54
exelius wrote: post #8

While this may be possible, I would worry about the effects on your liver. Ketosis does put additional strain on the liver, and while it doesn't seem like the side effects of extended ketosis are dangerous, there simply aren't any studies on ultra-endurance exercise during ketosis. And while studies on extended exercise during ketosis would be a good thing, they should be performed by researchers and doctors who know…

> our ancestors did not have a long life expectancy Historical life expectancy was skewed because of high childhood mortality. If you look at modern hunter-gatherers, life expectancy is still in the 30s, but life expectancy at age 15 is 54. This is still short by modern standards but everyone isn't/wasn't dying in their 30s. edit: Forgot link to paper: http://www.unm.edu/~hkaplan/KaplanHillLancasterHurtado_2000_...

Also, our life expectancy is increased even further due to modern medicine. But that isn't a validation of modern diet and lifestyle, we're just really good at stuff like fixing broken arms and treating infections.

Re: Running 50km after 82h of fasting

#63

Post by civilian »

gherkin0 wrote: post #45
weego wrote: post #16

The whole blog feels like a confused agenda masquerading as hand-wavey pseudo-science. Do not like. Ketosis is really quite well studied at this point, I don't really think this adds anything to the mix. Also why conflate fasting and ketogenics?

I agree. This guy seems like the type to latch onto weird fitness ideas, the weirder the better, without really understanding what he's doing. His last experiment on his blog was with some system to only sleep 2 hours a day split up into a bunch of naps. > Also why conflate fasting and ketogenics? Isn't fasting basically a ketogenic diet where you are your own food?

Idk, devil's advocate, polyphasic sleep schedule is definitely something to try if you're curious about things. There's a handful of notable people from history who used polyphasic sleep schedules because they felt that it gave them more energy and waking time each day. https://en.wikipedia.org/wiki/Polyphasic_sleep

At the very least I think we can get behind the idea of a post-lunch afternoon nap, which is a very limited form of polyphasic sleep.

Re: Running 50km after 82h of fasting

#64

Post by nicky0 »

tacos wrote: post #61
maxerickson wrote: post #57

Earlier quoted context omitted.

Should the talking to a doctor disclaimer come with a disclaimer that you should first make sure your doctor is competent? And a disclaimer to make sure that the person reading the comment is competent to assess whether their doctor is competent? And a disclaimer that there may be errors in the disclaimers, so think for yourself a little bit? Personally, I'll take an article like this one where the author doesn't muc…

You prefer less boilerplate in this situation, I prefer more. I consulted to law firms, perhaps you have not. Mythbusters say "don't try this at home" why can't he?

He can, but chooses not to.

Re: Running 50km after 82h of fasting

#65

Post by nicky0 »

rglullis wrote: post #56
PhrosTT wrote: post #5

I've seen people die running a half marathon. Please don't push your body to the breaking point just for giggles. Work your way up.

> I've seen people die running a half marathon. From the "Those who don't learn History are doomed to repeat it" department: the whole reason people "run a Marathon" is because of the legend of a Soldier, Pheidippides, running from Marathon to Athens and dying after announcing victory in battle. If people are aware of this basic information and still are stupid enough to run without any preparation, I'd say they woul…

Are you saying that the people who died ran without any preparation?

Re: Running 50km after 82h of fasting

#66

Post by kaonashi »

weego wrote: post #16

The whole blog feels like a confused agenda masquerading as hand-wavey pseudo-science. Do not like. Ketosis is really quite well studied at this point, I don't really think this adds anything to the mix. Also why conflate fasting and ketogenics?

> Also why conflate fasting and ketogenics?

He made the distinction between ketosis, a ketosis-inducing diet and fasting as far as I could tell:

> I’m suspicious that there are big differences between nutritional ketosis (induced by reducing the intake of high glycemic index foods) and ketosis induced from fasting. In other runs done in nutritional ketosis I didn’t feel that energetic (but it’s hard to compare since I’ve never done it that far in distance). That’s something I may explore.

Re: Running 50km after 82h of fasting

#67

Post by pc86 »

brianwawok wrote: post #39
pneumatics wrote: post #36

Earlier quoted context omitted.

This is a gnarly run. Almost 7000 ft of climbing (he gives the value in m, but all my reference points are in feet). It appears he was not auto-pausing, but did stop quite a bit. The time spent moving was 5:49. His pace, excluding the time stopped, was 11:12 min/mi. With the elevation gain, this is most definitely running.

To a decent runner that is nearly walking though. A record road race marathon pace is ~4:45 min miles. A slightly above average runner can do say 8 min miles over 26.2 miles on flats, which is only a titch under the 50k of this race. Trail races are slower, and 7000 feet is a decent amount of climbing.. but he was in no danger of setting any land speed record. 15 min miles is not that much faster than walking. So thi…

> A slightly above average runner can do say 8 min miles over 26.2 miles on flats

What is it about the running community that makes them say ridiculous things like this?

The fastest average marathon pace I could find anywhere was 9m 6s for 20-year old men.[0] To say that it takes only someone "slightly" above average to maintain a pace 12% faster than that for an entire marathon is ridiculous. Just because a lot of people do it every year doesn't mean that it's a great accomplishment. For context, that means someone finished nearly half an hour sooner.

[0] http://www.pace-calculator.com/average-marathon-pace-by-age-...

Re: Running 50km after 82h of fasting

#68

Post by Facemelters »

tacos wrote: post #2

I'm not sure if this is pseudoscience or anecdata but I'm sure I could find six doctors saying that this is a horrible idea. From the post: "I couldn’t find any publication about ultra distances and significant amount of fasting." This is not a medical study. This is an individual and could be anything from simply dumb and dangerous to body dysmorphia. Not everything can be safely hacked, friends.

This is DEFINITELY not a great idea without pre-clearance from a doctor, and even then it's not great for you. I would imagine this places undue stress on many body systems. Your muscles (and brain!) really really want glucose when you're working this hard. AND he was at altitude.

Ketosis workouts DO work very well though. I just don't recommend an Ultra while fasting...

Re: Running 50km after 82h of fasting

#69

Post by brianwawok »

IgorPartola wrote: post #50
brianwawok wrote: post #44

Earlier quoted context omitted.

I think you are conflating two things. Losing weight you do outside of races. Eat less, exercise more - you lose weight. Now during an actual race - do you want to burn sugar or fat? Your body has a TON more fat, even a skinny guy has 50k calories of fat he can burn.. whereas the same guy only has 2k calories of sugar to burn. However burning fat is less efficient, so you are unlikely to set a speed record doing it.…

OK that makes sense. So then what's the point of doing the fasting + racing thing? Seems like it'll just be very slow and difficult for you to do it.

Well in theory you run out of sugar calories after 2000 calories, but you have 50-100k fat calories. If he trains a lot in a fasted state, in theory he would have a much larger bank of energy to draw from. Many animals, for example dogs, mostly burn fat.

On the other hand, burning fat is less effecient, so your peak output is lower.

Re: Running 50km after 82h of fasting

#70

Post by xavivives »

tacos wrote: post #52
jimrandomh wrote: post #46

Earlier quoted context omitted.

This is a blog post on the author's personal blog. It doesn't even have ads on it. I really don't see a legitimate objection here. Just take the data for what it is - a report of something one specific person was able to do, which other peoples' physiology might or might not be able to handle, plus some speculation about our distant evolutionary history.

> This is a blog post on the author's personal blog No, the context is now reframed as a post on a highly-influential site, this one. The author is now commenting here, which is great. But "Don't try something like this without at least talking to a doctor, I probably should have" has yet to appear on the post. Therefore I reserve the right to state my objection.

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