Going carnivore and running?

(Alec) #21

The question I think is how you best top up your glycogen stores on the run when you know the muscle glycogen is likely to get depleted. There’s no question that a keto runner and carb runner will both start with filled up muscle glycogen. But as that is used up during the run, the question is whether gluconeogenesis is fast enough in a fasted-trained athlete (that means me!) to top up the glycogen stores fast enough to make the ingestion if sugar/gels on the run (as almost all runners do during a long race) irrelevant, or worse, counterproductive.

I had forgotten that I think I have the Volek et al book in my library somewhere. I might go and re-read that book.

(Bacon is a many-splendoured thing) #22

If you’d ever hit the wall, you’d know, believe me!

(Bacon is a many-splendoured thing) #23

And the other question is what you are planning on using that glycogen for. Running a marathon? Fat is the fuel. Sprinting, or a clean jerk (or whatever it’s called; the weight-lifting move)? That’s glycogen/glucose. I also suspect that training makes a difference, since the liver can store basically an unlimited supply of glycogen, enough to feed the muscles while getting gluconeogenesis going.

(Alec) #24

I am pretty confident that my normal training and life is well served and well fed by a good carnivore diet… I have proven this over the last 16 months. I did my half marathon PB a few weeks ago totally fasted ie no breakfast, start at 8am, finish at 10am, and no gels or food before or during the run.

The key question I am trying to ascertain is whether my body can keep up with my energy demands as I go longer than 2hrs. My first marathon is likely to take 4-5hrs, and I will run out of the glycogen that was originally in my muscles when I started… but is gluconeogenesis fast enough on the run to work and keep up with topping up the muscle glycogen so I don’t need an external source of energy such as sugar/gels or ketones.

I think that comparing me to Zack Bitter is a poor comparison… I will be going about half his speed, and therefore I may not need “rocket fuel”… the slow burn fatty acids could be quite capable of keeping up with my much slower speed…

(Bacon is a many-splendoured thing) #25

What will you be doing during the run that will deplete glycogen, if you are in fat-burning mode? This is the part I’m not getting. Isn’t most of a marathon endurance running, which is fueled by fat when we are in ketosis? What will the glycogen be used for?

I must confess I don’t understand a lot of the measurements Jeff Volek talks about, but it sounds as though the fat-adapted athletes are using mostly fat when they are exerting themselves. What am I not getting?

(Alec) #26

That’s an interesting question… and it might be the key one. Am I going slow enough to be using primarily fatty acids, and keeping the glycogen burn to a minimum? It is true that when we run slow we use more fat, but I think we still use some glycogen throughout a run… the key here is the mix, and how quickly I do burn the glycogen and then how quickly can GNG replenish what is used on the run.

I would imagine this mix is very individualised and depends a lot on what training you’ve done and how fat adapted you are. I know I am very fat adapted… I have been zero carb and running fasted for 16 months now. I am about as fat adapted as I am ever likely to be. But does that mean that I can run a marathon on mostly fat and not run out of glycogen… it is a very interesting question.

I will be testing this in about 12 months time. If I stop posting in 12 months time you will know that I died during the run… :joy::joy::joy:

(Bacon is a many-splendoured thing) #27

The easy way to test is to run the marathon without carbohydrates and see whether you hit the wall or not. Of course, winning is probably more important than testing a hypothesis, so we’ll never know. We had a forum member for a short time, who was interested in keto for the lift in performance, but had to give up because a six- to eight-week drop in performance while adapting to fatty acid metabolism was completely unacceptable, since it would interfere with his run times in a couple of races.

(KM) #28

When I was training I ran a half marathon length on a treadmill to get an idea of what I was in for. I didn’t have a very precise training schedule tho. Could you do a test run to see how you feel when it gets close?

To me running a marathon is a life achievement and if I had to supplement with frequent gels at my limit, I would. Literally, ymmv. :slightly_smiling_face:

(Alec) #29

This is the same for me. I used to run when I was much younger as part of being a triathlete. I did a half marathon or 2, and I also did a half ironman… 6.5hrs worth… that was hard!

At that time I also had a place at the London Marathon and I was in training for it, but got ill, pulled out and I have never entered another, and I have never done one.

But as you say, as a runner, it is one of those races/distances that is kind of iconic… it is hard, very hard, but most people can do it if they really want to and they train properly. I am planning for the Canberra marathon in April 2024, so this gives me a year to get properly prepared. And that includes figuring out how my body needs to be fed during the run… hence the extreme interest and mulling over this subject.

Thanks for your help and thoughts.

(Alec) #30

That’s funny! Winning is absolutely never in my mind nor even plausible. My “winning” is improving my personal best. When I do my marathon I will not yet be at the half way mark when the winners are crossing the line!

But thanks for having more faith in my ability than is realistic :joy::joy:. I am always going to be at the slower end of the scale…. Having said that, I am now coming around 20th in a field of 60 at parkrun (5k) each week. Yay!


I definitely never want to win (fat luck for that anyway). I am a hedonist and a stubborn one. I want to run a marathon or a half one or whatever I will stop at quicker than walking the same distance, that’s non-negotiable :smiley: And I actually expect being below 5 hours… But I couldn’t care less beyond that. Doing the distance when I can’t run for a few hundreds of meters now (I am trying since a few years but with almost no effort and I dislike running. I just want to learn it. I LOVE walking and hiking and if I can choose between walking and running, I usually choose walking), that would be plenty. Beyond that enjoyment/lack of suffering is my only goal. Okay, maybe it’s true for everyone but they get out more joy from being quick. I don’t. Running a marathon would be a not even very tiny miracle for me… Even though it’s realistic but theoretical possibilities mean little in my case. I can mess up even easy looking things!
I am very competitive, by the way but not when it comes to running, something I am awful at. I don’t care much about my speed when hiking or cycling either. When it’s cycling, I try not stopping all the time but if I get tired or warm or thirsty, I do… I just don’t do hard things. My cold showers only happen when they cause no suffering at all, it’s impossible for me to do them when I don’t want that level of coldness (hence I never do them in winter when the tap water is 5C or less. that wouldn’t be nice)…

Erm, sorry, just wanted to express one may not care about the time that much (of course I would like to be quick, well no chance for that… and I will try as long as it’s pleasant enough… it’s not fully indifferent but not really important for me).

And Alec, I am looking forward to your experiences! You made me more curious, maybe it will help me to break some barrier at running. I believe if I could do it regularly, I would eventually get better and run longer and it even would be easier than now.
I agree with you, by the way. It must be individual, it is a mix and a slower marathoner probably won’t run out, it would make no sense, people used to run for hours well fasted without problems… A half marathon for a normal person should be fine, sprints are fine as they are short… A very intense marathon? No idea. Do we have some info about it? The pros probably consume gels and whatnot… Did some try it without? It would help us out :slight_smile:

(KM) #32

Lol. Ya, my friend’s eyes got round when I announced I was doing a Rock n Roll half. “Do you think you’ll win?” Over 20,000 other people??? :rofl: The challenge wasn’t winning, it was finishing!


Nah you were only shooting to be one of the first 5 over that finish line :crazy_face:


Hi Dave, I do Keto/fasting for a few reasons one of which is climbing. It took me months to get adapted and I can still get it wrong.

I think if you tried to change how you eat in the situation you suggested it wouldn’t go well. I think Keto flue and not being fat adapted will be huge problems. In fact I can’t imagine a worse way to experiment.

I’d start in a situation where you’re in control, willing to experiment and not under any performance pressure. Don’t expect to get better for a few months.

I’d imagine that Keto/fasting will give you huge benefits in running especially as you’ll probably be able to stop yourself hitting the wall - maybe. You’ll probably be much more metabolically flexible and able to cope with fuelling your body from fat.

Best of luck

(David Cooke) #35

I guess I should have mentioned that I am low carb most of the time, and generally train fasted.


Ah in that case I’m really interested in how it goes/went!

(Alec) #37

There was an interesting passage in a YT video I was watching yesterday with Dr Chaffee… he was definitely in the camp of “if you are fat adapted, you can do endurance activity for many hours on fat and not run out of energy”. He was very clearly saying: don’t take carbs, there is no need. I think the relevant section was at about 44 mins.

I want to believe this, and this is my gut feel as to what is right. But I don’t yet know this is right (for me!).


Sounds like you already have your answer.

(Alec) #39

I am not sure yet though… for me, this is still an open question. When I do my next half marathon, I think I will take some ketones and see if it changes anything. And during marathon training, I may do some tests on long runs on both ketones and (carby) gels.

My current plan is to do it without additions of either. But I think it will be worth doing some testing in training and see what happens.


My answer always was ready: I try and we will see. Most things related to how our body responds to a situation is quite individual. It’s good to know what to be expect, what theory and even other people’s experiences say - but in the end it’s our unique case.

I got a bit more motivated to start to run (and talked with my SO and he entertains the idea to have longer runs here and there). It would be nice to experiment and compare to my high-carber SO. My guess is that if we will be able to run a marathon, we will be able (and prefer) to run it fasted. We already has a very strong aversion against consuming anything during/before running and he proved that a half marathon is no problem but even he never run longer let alone me.

By the way, yesterday I run into an article about how to eat when running… Of course it was some usual carby BS, I just got reminded again to the (to me) very strange thing that people imagine their body is STARVING if they don’t eat almost constantly when exercising. Skipping half a day is nothing! Even if it includes a not too long run (I mean, not the 120km that is possible during that time for some people :wink: I am still on the fence regarding marathon distances but surely many are fine doing it fasted). The article writer seemed to think that even a teeny-tiny run shouldn’t be done without some serious thinking about how we eat. But if we already eat properly for a sedentary lifestyle, what could a tiny run change? Many people are so obsessed with eating very often… Don’t they know and well, experience that their body has reserves?
Or maybe it’s for people who need many tiny meals all day long…? Still, an article writer should be aware that most people aren’t like that… And probably most people could get used to a more traditional lifestyle with more exercise and less frequent feeding… Isn’t that natural? We evolved like that.