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Running 50km after 82h of fasting

blog.xavivives.com

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Re: Running 50km after 82h of fasting

#41

Post by runjake »

pneumatics wrote: post #36
runjake wrote: post #23

A couple points: * He ran 50 KM in 7 hours and 45 minutes, which amounts to fast walking. In real terms, he probably ran some but probably walked most of it. * If you're going to do something like this, please do it under the supervision of a medical doctor. A 50km isn't a big deal, virtually anyone who can run a marathon can run a 50k, but people do die during this events. Respect the distance. Edit: Here is his Str…

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.

Good, thanks for the clarifications. Pretty admirable performance.

Re: Running 50km after 82h of fasting

#42

Post by runjake »

bluedino wrote: post #35
xavivives wrote: post #27

Earlier quoted context omitted.

I did ran all the way. Surely it wasn't fast, but take in account that there was 2000+ meters of elevation gain.

15/min miles make that more of an 8 hour 'walk'

See the clarifications from pneumatics. It looks like he ran it, just stopped a lot.

Re: Running 50km after 82h of fasting

#43

Post by ygjb-dupe »

powera wrote: post #21

Could all the people without medical knowledge please stop saying that their lack-of-medical-knowledge make them smarter than the guy that actually did this? Your requests for various random chemical levels are stupid. We have done science for thousands of years before blood tests were invented.

Yeah, we did science for thousands of years, but medical science has had (and still has) to contend with pseudo science and snake oil continuously (for a modern take, see homeopathy).

An anecdote about a personal experience in relation to an exercise and diet regime doesn't make a person smart, and asking questions about the experience doesn't denigrate the author of the anecdote.

Weight loss and nutrition are the bogey man of the health industry, and anyone claiming a new, better way of doing things is inviting harsh criticism - as long as the idea is under attack and not the person, there is no harm done.

Re: Running 50km after 82h of fasting

#44

Post by brianwawok »

IgorPartola wrote: post #40

I just started training for my first marathon, and am trying to do some reading on the subject. Hal Higdon's position is I guess what you might call "traditional": your muscles use glycogen as the preferred energy source. Around mile 20 is when most people deplete their glycogen and start burning fat as the primary source of energy, but this is much less efficient, resulting in a performance drop. If this is indeed t…

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. An ironman is a 8-16 hour race that burns 5,6,10k calories, and all the successful people I know do it via eating a lot of sugar during the race. In theory you COULD do it off fat, but no one has won a race (that I am aware) doing that, so it seems to not work as well in practice.

Re: Running 50km after 82h of fasting

#45

Post by gherkin0 »

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?

Re: Running 50km after 82h of fasting

#46

Post by jimrandomh »

tacos wrote: post #37
jessep wrote: post #34

I applaud the author's spirit of mad science and adventure. As someone with a lot of doctor friends and family, I think it is pretty clear most doctors are not familiar with the relevant research and by default give a cautionary response which merely parrots back the status quo fears, but they're even more risk averse due to malpractice concerns. In terms of getting your blood work done, sure, I'll agree that seems i…

Do what you want privately but the value proposition changes when you publish your self-experimentation world-wide. More so when you promote it. And yet more still if and when you try to profit from it. There are clear and common ethical standards here and the blog post comes in well under them.

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.

Re: Running 50km after 82h of fasting

#47

Post by ErikAugust »

He did it in 7:45. They don't stop the race timer because you stopped.

That's towards the back of the pack for a trail 50K with that kind of elevation profile.

It'd be better as an experiment if we measured the author's VO2Max, his 1 mile run time on a track, and then ran the 50K on a track. Measure ketone levels, etc.

Re: Running 50km after 82h of fasting

#48

Post by mrits »

Congrats on not dying I guess. As someone who has been around elite athletes my whole life an article like this doesn't phase me at all. A bad diet can throw the best athlete off her game. On the other hand, Michael Jordan can win the NBA finals on nothing but water and flu in his stomach. There are a lot of factors on what it takes to get through a 50K. I think a lot of us runners could do it starving ourselves, but we'd just feel very bad the whole race.

Re: Running 50km after 82h of fasting

#49

Post by runjake »

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…

pneumatics corrects me and says his actual moving pace was 11:12 min/mi. This is a pretty good pace, given the terrain, and far beyond speed walking.

I've run everything from flat, paved marathons to alpine mountain ultras. The paces are totally different. I'm going to be running a technical ultra a good 3-4 minutes/min slower than I'd run a flat road marathon.

Re: Running 50km after 82h of fasting

#50

Post by IgorPartola »

brianwawok wrote: post #44
IgorPartola wrote: post #40

I just started training for my first marathon, and am trying to do some reading on the subject. Hal Higdon's position is I guess what you might call "traditional": your muscles use glycogen as the preferred energy source. Around mile 20 is when most people deplete their glycogen and start burning fat as the primary source of energy, but this is much less efficient, resulting in a performance drop. If this is indeed t…

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.
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