Running 50km after 82h of fasting | Hacker News Reader

Running 50km after 82h of fasting

blog.xavivives.com

132 pointsxavivives120 comments

I did not see a doctor. Not before, not after. The truth is that even if I had seen one I wouldn't take in account her opinion anyway.

The current standards for nutrition are based on a diet rich in carbohydrates. Any response from a doctor (at least the ones I have access to) will discourage this event. It just doesn't fit on their models. Plus they have to play safe. I appreciate all the people who are concern about my health. I'm doing fantastically well. Thanks.

I do believe that ketosis is the "default" state for the human being. I have plenty of reasons for that and I'll try to explore more arguments in other posts. Its a very broad subject and I wanted to narrow the scope.

I didn't do this experiment out of nowhere. I've been running in ketosis for long time and I know myself pretty well. I've been reading and educating on the subject. I'm not completely stupid. I know the risks and I know there is a lot we don't know about. But if I've done it its because previous runs and experiments gave me the enough confidence.

This post doesn't suppose to be a scientific study, not to give any medical advice (I'm taking note from your comments and I'll add a warning). Its just my experience based on what I thing should be a more commmon approach, to focus more on the fundamentals than on a micro view.

Personally I've come around to your point of view. Every week I play a very intense sport consisting of a lot of quick short sprints back and forth for hours and I've self experimented with going the full carb loading route and also the full ketosis for weeks route and repeated a few times over the years. When I play after the low almost no carb eating way I have far more stamina, much greater than people half my age who are playing with me. However I also find it takes a bit longer to warm up and get my wind under low carb but only by a few minutes.

I highly encourage anyone to try this out for themselves the difference can be startling.

here is scientific explanation for some of this:

http://www.pponline.co.uk/encyc/strength-and-endurance-train...

and

http://www.pponline.co.uk/encyc/strength-and-endurance-train...

Everything on that site is subscribe-walled (one could use a phony email, I suppose), and even his cookie disclosure has a phony link. I stopped there.

There is a very hard to see "No thanks" button in red just below the nagware.

Still, it might have been interesting to have your blood work done before and after to see what the changes were. There's compelling evidence for fasting. See Micheal Mosley's Eat, Fast and Live Longer documentary:

https://vimeo.com/103656060

Personally, I'm following a 5:2 intermittent fast this year while also maintaining 63 mi/week running, including 9 mi on the days I fast.

  See Micheal Mosley's Eat, Fast and Live Longer

Also see Mosley's The Truth About Exercise:

http://www.kpbs.org/news/2013/apr/08/truth-about-exercise-mi...

True. I'll try to get a blood test next time. What are you guys recommendation on what to check?

I too, would like to know what blood tests are useful in this effort.

I am not a doctor. You should definitely talk with a doctor. But, you can google for "health blood markers" which typically includes measuring cholesterol and glucose to start with. For example:

http://www.marksdailyapple.com/blood-test-markers/

http://circ.ahajournals.org/content/107/3/499.full

https://labtestsonline.org/understanding/analytes/cardiac-ri...

Also, it's probably not a bad idea to measure your blood pressure regularly which you can easily do at home.

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 interesting.

My father, a doctor, used to be afraid of low carb/ketosis diets, because "bacon, cheese". Years later he read the relevant information and completely switched camps.

Finally, self experimentation can be dangerous, sure. But that doesn't mean it isn't valuable and interesting. Do you think people should never do potentially dangerous things in pursuit of adventure, knowledge, truth?

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.

> 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 much represent any of it as advice over an article that claims to give a bunch of advice but qualifies it with a disclaimer that it might not apply, check with an expert.

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.

Warning added.

You're not giving enough credit (or responsibility) to readers to say "Hm, I should consider the risks and other considerations before implementing this myself".

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 Strava entry for the event: https://www.strava.com/activities/morning-run-436423654?utm_...

From my sloppy napkin math, it looks like he ran the distance (slowly) and probably stopped a lot and had his device configured to pause the time when he stopped.

I don't mean to sound down on the guy, he got out there and did 50km. And he specifically mentions he's no athlete. I am glad he documented his experience. But please don't use this as part of any "Couch to 50K" kind of scheme. Ketosis doesn't work like creatine.

Edit 2: A metric/imperial conversion pace chart here: https://www.globe-runners.com/sites/default/program_builder_...

Edit 3: pneumatics' comment, below corrects me: "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." This is a pretty good performance for a newbie, IMHO.

For those saying it's slow, you've either never ran an ultra on rough terrain, or you've been on the cover of running magazines.

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

I found your Strava data and updated my comment.

And pfft 2000m+ elevation gain over 50km. Those are gently rolling hills ;-)

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.

50K isn't easy for even people in good physical shape, especially if there are hills!

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 this proves you can speed-walk an ultra in a fasted state. Which is cool and shows how strong our bodies are. scott jurek is amazing at ultras, and a vegan - but he definately eats and runs off sugar.

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.

50k in 7:45 is 15 minute mile pace (14 min 58 second to be precise).

I don't know what this moving pace thing is, if you choose to take a 45 minute break that still counts on the clock.

So at best, his 15 minute technical ultra translates into a 11 min mile road race, which is below average.

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

I make that a 3:30 marathon which I would suggest is rather more than "slightly above average" - you'd be in the first 25% male finishers at London 2015, for example.

I consider 25th - 40th percentiles as slightly above average... as many many of those people in your race are running their first and only marathon. Of people who do at least 1 marathon a year, I don't think you will find a 3:30 marathon much past the middlepoint. Not even close to an open BQ time for example.

While your intuition here may well be valid, to an outside observer it looks like you're cherry picking numbers without justification. Why 25th-40th percentiles? Do we know the distribution of first-and-only marathon runners to repeat runners or is this a pure intuition? If the latter I would be concerned about the flaws that exist in human thinking when it comes to generalizing over groups.

> Why 25th-40th percentiles

Why not? Someone wanted to quantify "slightly faster than average", so I made up some percentiles. I don't think there is a scientific definition of "slightly faster than average" so I think I can do this. You could I suppose counter with you think it means "35th-49th percentiles" which is valid but doesn't really change the argument too much.

> Do we know the distribution of first-and-only marathon runners to repeat runners or is this a pure intuition?

Just intuition. It would be a tricky thing to survey, as you would need to wait for all current people who have ran exactly 1 marathon to die, to confirm they do not indeed run more .

> Do we know the distribution of first-and-only marathon runners to repeat runners

I did look for those stats for London but I couldn't find anything relevant - I'd assume they collect that information on the entry form but it's possible they don't or just don't care to publicise it later.

http://www.theguardian.com/lifeandstyle/the-running-blog/201...

> The average finishing time globally for 26.2 miles in 2014 was 4hr 21min 21sec – about 40 seconds faster than the average for the period 2009-2013. Men’s average finishing time was 4hr 13min 23sec, while women’s was 4h 42min 33sec – 29min 10sec slower.

I'd suggest your 3:30 was still definitely more than "slightly above average".

If you want to quibble about the median instead of the mean,

e.g. http://www.nytimes.com/2009/10/23/sports/23marathon.html

> In 2008, the median finishing time [for men] was 4:16, a pace of 9:46.

Which still puts 3:30 way above, I think.

Just as a point of reference I ran this 30k [1] (18.6 miles) at 8:38 pace vs. a flat road half marathon (13.1 miles) at 6:41 pace about 5 months later.

As you can see in this [2] it climbs from a low of 2500 feet to 3700 feet. I'd estimate 1500 feet total so much less than in the article.

I usually place in the top 5% of men in most races.

[1] http://www.othtc.com/ultra/course/Course.htm [2] http://www.othtc.com/ultra/course/ultra%20maps/30kprofile.jp...

> 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-...

That site seems pretty bogus.

Lets pick a real race. Say the 2015 Chicago Marathon.

Let's look at men 30-34

http://results.chicagomarathon.com/2015/?pid=list

3200 people there finished. So let's take middle, #1600: 4:11, which is 9:34 pace.

8 min pace is 3:29, which is something like finish 700 / 3200 in that age group.

So to me, finishing in 700th place out of 3400 people in a race is "slightly above average". But who cares, even the 9:30 pace is far above the 16 minute pace of OP.

Realize too, that many people running a marathon are running their 1 lifetime marathon - they never ever plan to run another. Drop all those out, and you will find 3:30 may be about average or even a tad worse among people who are serious runners.

> That site seems pretty bogus.

I agree, my point was that the fastest "average" time I could find (regardless of quality of the source) was still sufficiently slow enough compared to the 8:00 pace figure that 8:00 is in fact not slightly above average.

I'm not a huge runner, but an 11 minute mile over that distance is great. An 8 min/mile marathon run is a highly experienced runner and not just someone slightly above average.

Good, thanks for the clarifications. Pretty admirable performance.

For reference on how to normalize the elevation gain, I like to add 1.5 miles for every 1000 feet of elevation gain/loss (combo). So, in the way I plan, I'd look at that 50k like a 41 mile run on flat ground.

I can't comment for running, but for backpacking we would add a mile for every 1000 feet of gain, ignoring loss. So 500 up, 400 down, 500 up feels like an extra mile. You have to look at elevation maps to get the nitty-gritty, but I've found it to be pretty fair.

Running means you are jumping through the air, so that at most one foot is in contact with the ground at any time. This can be done without moving forward, so there is no lower bound which separates running from walking. Walking means that at least one foot is in contact with the ground at all times, and there are at least brief periods of double support (two feet down).

I can walk up to an 8:30 mile pace. Elite race walkers can outwalk recreational runners; the paces are around 6:00 at that level, which is astonishing (though not in comparison with elite running of course).

If someone covered some distance at 11:00 to the mile, we have no idea whether they ran or walked without eye witness or video evidence of what it is their legs were doing.

I definitely ran my first marathon in 2003, in some 5:05:12. That's like 11:44 to the mile or thereabouts. I definitely made a point of not taking any walking steps in this thing. It happened by accident several times, but I immediately went back and re-ran those small stretches of the course where I had strayed from the pure running discipline. On subsequent ones, I didn't make a point of that at all, just the first one. I've never taken planned walking breaks or walked extensively, but I never re-ran any walked steps. The clock is ticking; no time for foolery! :)

Strava shows the spent moving time by default. If you want the overall time to be shown you have to tag it as a "Race". https://strava.zendesk.com/entries/22428904-Using-Strava-Run...

I also want to point out that when running barefoot/minimal you reduce the stride and increase the cadence. In my experience the result of it is that speed its generally reduced, specially downhill and flat surface.

And by going completely barefoot the surface of the terrain it really defines the speed you can go. When going fast the pressure on the sole its greater and if the terrain its harsh you are forced to slow down. A lot of time until the point of walking, or even slower. In complicated terrains the potential outcome for stepping over the wrong stone it really makes you to be conscious about every movement, slowing down as well.

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.

Oh, I totally agree. It's just, like most things, you can take it too far. Only sleeping 20 minutes every 4 hours for a total of 2 hours of sleep per day is too far in my book.

> 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.

Ketosis should have a uniform effect, whether induced by fasting or keto eating. What makes the former more fatiguing, psychological effects aside, is the lack of instantly-available free fatty acids.

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.

My experience in endurance sports is with cycling, and I have a friend that used a "ketosis" diet to help lose some weight. My understanding of the fat burning process is that it can only happen so fast, so with fat as your fuel source you are only able to support moderate intensity levels. This could explain the 7h 45 min minute time for his 50km run (~31 miles).

I know if I am riding at race pace for a couple of hours and don't give myself fuel then I am in trouble, but riding at lower intensities I can go for a much longer time without eating as long as I have water.

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 true, then I guess it means that if your goal is top performance, then carbs are your friend. If your goal is fat loss, then low-carb diet plus long endurance exercise is for you. Does that seem right?

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.

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.

That makes sense. So basically as long as you don't run more than 20 miles or equivalent, the benefit of low carb training is less noticeable.

One more question: what about proteins as a fuel source?

So taking a step back, as you go about a day you are always getting some energy from sugar stores, and some from fat stores. Example graph:

http://www.sportsscientists.com/wp-content/uploads/2010/01/F...

Sitting still mostly fat. Normal person as you work harder, more and more come form sugar stores - as it can get you energy faster.

All this is separate from calories you are taking in. You could eat sugar (sports drink), fat (an avocado), or protein (bacon) while you exercise. Your body will turn all of these into "sugar" which will then fuel your muscles through sugar. Fat is the longer term storage mechanism in the body. So while you could fuel a race by eating avocados or bacon, most people would have stomach issues.. as your stomach starts to shut down the harder you work (blood is in muscles not in gut, etc.). So this why when we talk about fueling in a race fat vs sugar, it's not really related to the source we are taking in our calories from.

You can, perhaps, train yourself to burn fat more efficiently which helps.

e.g. http://home.trainingpeaks.com/blog/article/using-low-carbohy...

Cool. Though your linked article still states that peak fat burn output is still lower than peak carb burn output and that high intensity still is best served by carb rich diet.

"high intensity" is sprinting, not distance running.

Well you are burning quite a few more carbs than fat even at a fast 1/2 or full marathon. Not sure exact switchover from more carbs to more fat is, maybe 5 or 6 hours?

"Well you are burning quite a few more carbs than fat even at a fast 1/2 or full marathon"

No, you aren't. Your liver can hold only so much glycogen, and you'll use that up well before the 10-mile mark.

http://www.ncbi.nlm.nih.gov/books/NBK22417/ suggests that an elite athlete (they're talking about 2 hour marathons) could fuel about 1:20 of that with glycogen (~18 miles) but that they burn about equal glycogen/fat (which would give 13 miles of glycogen.)

I suspect your 10 mile mark is probably correct for anyone below "almost-elite".

For a community of 'hackers' (which I assume should embrace trying out new things and questioning traditional values), the majority of these comments sound very negative and not constructive.

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.

My resources are limited. But given the chance I won't mind repeating it.

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 think you have to think about how those people died. Heat exhaustion? An underlying heart condition? I don't think they died of not having enough nutrients, or not eating soon enough before running.

Yes heat.

http://articles.chicagotribune.com/2011-06-04/news/ct-met-ha...

I'm just saying the whole "Push through the pain" adage is dangerous.

Sometimes stroke or similar, caused by incorrect hydration by just drinking lots of plain/plain-ish water which leave various useful things in your body too diluted to be useful. Sometimes an exacerbating factor in heat stroke, so not diagnosed as the heat stroke is seen as the only problem and other causes of heat stroke are assumed. See https://en.wikipedia.org/wiki/Water_intoxication

Actually seen firsthand, or read about it having happened? (These are very different, because they imply much different prevalence.)

The author of the article records a short clip describing how he's feeling at each waypoint, and doesn't seem to have pushed himself terribly hard.

I was watching my fiance run and someone died literally right in front of me at the Brooklyn half-marathon in the fall (he was a young guy - I'd say late 20s). He collapsed right at the finish line and they couldn't revive him. The crazy thing is there was no mention of it after the race or anywhere, I tried googling to find out more info. but nothing. The only info. I found was on /r/running people where people who were also in attendance were talking about it. Marathons just seem so unnatural to me.

Very often overhydration causes electrolyte dilution that stops the heart.

Solution: Install a salt lick every 5 miles or so.

> 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 would be candidates for the Darwin Awards.

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

No, I am saying that the people who "run past their breaking point just for giggles" (to use parent's term) are acting so carelessly that I don't care if something fatal happens to them.

Call it "self experimentation" all you want, but the OP running a 50k while on 4-day fast is plain stupid. It would be by his own damn doing if he died or done any serious harm to his body.

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 what the risks are and can monitor them appropriately.

IMO this is dangerous. Just because our hunter-gatherer ancestors did it doesn't mean it's healthy for us. For all we know, this type of activity could wreck your liver and contribute to dying in your 30s (our ancestors did not have a long life expectancy). So even if it was a survival adaptation, it may have ensured the survival of the herd at the cost of the individual.

I link a small study of endurance athletes performance while in ketosis in another comment.

Please cite your sources. It's certainly possible that it's dangerous, but there is also a tradition of labeling anything which is different than what was historically done as medically dangerous. There is an equal tradition of pulling the medical dangers of various things out of thin air based on guesswork. It is of course possible, I am very interested in reviewing your sources.

> 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.

>Ketosis does put additional strain on the liver

Do you know what you're talking about? Fructose metabolism and alcohol metabolism also occur in the liver.

Keto reverses non-alcoholic fatty liver disease http://link.springer.com/article/10.1007/s10620-006-9433-5

Many tissues can use ketones directly as fuel. https://en.wikipedia.org/wiki/Ketone_bodies#Uses_in_the_hear...

I've played with ketosis. You can verify your body is in a state of ketosis using "keto sticks" that you pee on. They change color and prove that your body is outputting ketones. That's also what causes your breath to smell like something died (my wife's comment).

One of the leading thinkers on this is Tim Noakes who has written some excellent literature on the subject and is a keen runner. He became famous for "Lore of Running" which is a tome of a book but is an excellent primer for any runner serious about nutrition and metabolic processes.

Noakes has more recently joined the low carb/low GI movement and has some pretty radical thinking in the area.

I would also echo some other commenters here that Ketosis is IMHO not a healthy state and can have quite far reaching health consequences. One of the by products of ketosis is acetone which is what makes your breath smell - so there are some fairly radical changes in your body's chemical functioning as it goes into starvation and survival mode.

I tend to gravitate away from radical experiments like this and more towards what the leading edge professional athletes are doing, minus the steroids. They have plenty of motivation to innovate in the field in a sustainable way.

>I would also echo some other commenters here that Ketosis is IMHO not a healthy state and can have quite far reaching health consequences.

Are you a doctor? Are you qualified in any way to be giving health recommendations?

No? Parroting the crowd doesn't help people. Especially people with insulin sensitivities that could absolutely be helped by a low carbohydrate diet.[0]

0: [pdf link] http://download.springer.com/static/pdf/335/art%253A10.1186%...

> so there are some fairly radical changes in your body's chemical functioning as it goes into starvation and survival mode.

Ketosis is not a "starvation mode", it's just one of the normal ways your body provides energy. During most of human history people didn't have plenty of carbs available all day long, so ketosis was most likely the normal state and not an exception.

"Starvation mode" because of eating less is generally just a myth and an excuse for people why their diet failed.

So, I played with ketosis and lost. 7 years ago I weighed 260lbs, having converted a once fit and muscular physique into lard with the help of my desk and startup. I decided to do something about this, and to simultaneously run an experiment to determine my general metabolic rate and baseline nutritional requirements.

To do this, I stuck myself on a fixed daily 700kcal diet, ran 15km a day, and got on with life as usual. I measured blood sugar, weight, fat mass, resting pulse, b.p.

Needless to say, I lost weight, fast, and was down to 180 by the time I ended the experiment, four months later. 80% of the mass I lost was fat, 20% muscle, my sleep apnoea was cured, and I felt good about myself for the first time in years.

I also got some beautiful graphs out of it. By keeping the inputs all constant, I could see my weight shifting along a curve as my metabolic requirements shrank as I dropped mass, I could see blood pressure and glucose moving in curves beautifully correlated with my fat mass. To that end, everything went as planned.

About six months after this, I started being sick. I'd spend days puking and delirious, and would then be fine for months, or weeks - came and went at random. Several years of baffled doctors later, I diagnosed myself with gall stones, got an ultrasound, confirmed my hypothesis, and had my gall bladder removed last year. Turns out that having a prolonged low calorie diet pissed my duodenum and gall bladder off mightily, and they grew a huge cluster of stones in short order. I'm seemingly fine now, after five years of misery.

Long story short, you're not actually invincible, don't learn this the hard way like I did.

Sounds like you played with starvation and lost.

Ketosis does not require or imply a severe caloric deficit. It requires a very low carbohydrate intake, but you can eat a maintenance level of calories and be in ketosis.

None of the standard guidance (e.g. [1]) for a weight loss program using a ketogenic diet advocates such a severe deficit. Presuming you're a male of average height, 700 kcal is about a 75% deficit. By all appearances, that was the source of your troubles, not keto per se.

I'm glad you recovered all right!

[1] http://keto-calculator.ankerl.com/

Certainly an interesting experiment.

As somebody who only engages in "moderate" endurance activities (bicycle rides ~100 miles) I can relate the difference diet makes for me on long activities.

Endurance athletes speak of a thing called the "bonk"[0] - a point beyond which continued activity becomes much more difficult. This state is due to the exhaustion of glycogen stores in the body.

I've encountered this only a few times, but it's a really interesting phenomenon. In times I do not prepare well enough, I just run out of "energy." Everything gets harder, and I don't recover from it. It's not the case that I cannot continue, but continued exertion feels much more difficult. I feel mental fatigue as well, and I have felt "light headed" in this state.

This is why it is recommended to consume carbohydrates when engaging in endurance activities. It's not that you can't continue on ketosis, it's that you continue in a very suboptimal manner, and in something like cycling (where you are moving quite quickly) a sensation of light-headedness can be exceptionally dangerous.

Incidentally, the rate of depletion of glycogen stores is relative to the intensity of the activity. Operating further below the aerobic threshold will allow one to deplete the glycogen stores more slowly. If the OP is in good shape, this probably played a role in his success, as he might be running at a less intense pace than he would be capable of were he consuming carbohydrates.

[0] https://en.wikipedia.org/wiki/Hitting_the_wall

Hacking your own body can lead to health issues obviously. But...

This may be the way everybody runs in the future.

A bit like Cliff Young[1], a potato farmer that won the Sydney-Melbourne ultra-marathon.

[1] https://en.wikipedia.org/wiki/Cliff_Young_(athlete)

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.

> Weight loss and nutrition are the bogey man of the health industry

They've become a bogeyman of internet forums too. Throw in weight lifting for the trifecta.

I'd like to add my own data points for low-carb/ketosis and exercise. In the beginning it was very hard and I felt extremely lethargic (typically 3 to 4 days after switching to < 30g carbs a day). My exercise at the time was 2 miles on the treadmill and 20 minutes of full body weight lifting (squats, etc).

The worse I ever felt was during that time (3-4 days in). After that I would slowly improve and within a few weeks could almost reach my normal max, though never exceeded them. The bonus part was that I was melting off pounds of fat.

This was just my experience. I found that salty drinks (such as chicken stock) helped a lot when first beginning low carb to prevent the lethargic feeling ~3 days in.

Ketosis sounds nice and all but it makes ones breath stink bad. I think id rather be fat.

I think the vinegar-scented sweat is even worse...

Not something I would try, or would have tried at what I suppose is his age. I will say a runner in training can get into ketosis with no need for fasting--visiting the downwind side of marathon finish chutes would probably convince you of this.

I did "hit the wall" a couple of times, but my diet leading up to the race was no different from that before other races. In one case it was inadequate training. In a couple of others it was setting out at too fast a pace. Now, that is not to say that I felt good in the others--I felt awful but bearably awful.

I think the most important factor should not be whether you can do it or not, but if you can perform better in ketosis than those who are not in ketosis.

In Ironman and related circles it is conceded that performance is decreased, but the reduced calorie requirements in races often mean better results due to less, err, gut complications.

I know the 4 months I went on low/no carbs, I had never felt better, had more energy, or lost weight faster. I lost 43lbs, saw my cholesterol and triglycerides go from marginal to perfect, and ate as much as I wanted.

Course then my gallbladder stopped pumping and I haven't tried it again, although I don't see why I couldn't.

I once tried just 16 miles after just 36 hours of fasting. It was interesting. I don't remember a whole lot, other than that it was a serene kind of experience. I was in quite a different mental state from the run-of-the mill run.

Funny that this gets upvoted so high and a more reasonable article that was posted in the same day (https://news.ycombinator.com/item?id=10931349) did not.

I've done ketosis, high carb, and moderate carb, and the fact is that while ketosis can work for some, it can be damaging to others. I tried keto for a while and it raised my fasting blood glucose levels to pre-diabetic levels. As soon as I went back to a moderate carb intake, my blood glucose was back to near-ideal. Obviously you should take further tests (HbA1C) to be absolutely sure if you're at risk, but it's not all smiles and rainbows for keto, you really need to make sure your body can actually adapt properly to the changes that are going on in your body as a result of the diet that promotes keto.

I've had a similar experience. I researched that and found that in those conditions having a fasting glucose that is higher than the "normal" range is not a problem, just an adaptation. I had HbA1C done several times and the results came back perfect.

More people find articles discussing what is possible more interesting than a summary article. Xavi was interested in ketosis, read about the subject, saw that runners like Tim Olsen had done well on a paleo-type diet and wondered about long-distance running in ketosis, followed through on the experiment, and wrote it up. To me that is the ideal thing to post here.

«And they were hunting because didn’t have food in the first place…»

I laughed at this one.

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.

The only fundamental difference between this and a 'proper' scientific experiment is the p value. All scientific experiments have cavets, and all have a probability their finding could be erroneous. Of course, no one should write a textbook based on this one guys self-reported experience. But, assuming he is accurately reporting it, it is evidence that this is _possible_ which is a very important thing to discover.

Yes, it may only be possible in 0.01% of the population, that is the type of thing which a larger-scale study can evaluate, but whatever they find, it will be an interesting result which would have been less likely if he hadn't shown it could be done.

Nonsense. A proper scientific experiment would have controls and independent results and medical oversight and calibrated measurement equipment and a clear definition of what's attempting to be proved.

This is a guy fooling around and blogging for attention. Dangerously so. p=1, no scientific method = anecdata. His conclusions? Pseudoscience. It's dangerous to him personally and it's damaging to society broadly to promote such without caveats. So I'm providing them.

He has gathered more data than had he not done it, or not blogged about it. You're right that it doesn't meet any scientific criteria for 'fact' yet, but it is data of a sort, and may be a helpful step on the road to the furtherance of science.

Wow. I didn't realize "doing random stuff while taking no measurements, and then later writing about it" qualified as "the furtherance of science." A sample size of 1, combined with an attitude of ignorance and machismo, helps explain why "medical remedies" like bleeding people with leeches and giving them liquid mercury to drink endured for hundreds of years despite no actual evidence that they worked or were safe.

Reality check: nutritional deficits lead to cognitive deficits. The Atkins diet is known to lead to heart disease, which Atkins himself died from.

A proper medical study also has doctors monitoring for any risks. They would run blood work and check for anything wrong - it's hard for one person to draw conclusions about how healthy this is if he wasn't baselining and monitoring different vital statistics (liver enzymes, etc.)

Also, everyone's body is different: he may just be a genetic freak who is able to do this. Especially with heath/body claims, be very wary that one person's results will be able to transfer to anyone else.

Your point is valid, but your wording could have been better (I assume that is the reason for the down votes).

He doesn't mention consulting a doctor to explain the health risks before undertaking this. In my opinion, even if you think a medical professional is going to say you are stupid for trying it, you should still consult a medical professional. You need to be aware of the risks and their signs, and when you post something like this on your blog, it should be prefaced with you probably shouldn't try this.

What if someone dies trying to recreate his experiment? (I know common sense etc...)

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...

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