Training for an Ultra on Keto!


(Hansel) #1

So, there’s a trail ultra here in my “backyard” on June 7, 2025 and I’m definitely going all in on this race. Please note I have no intentions of winning, I’m not seasoned enough and not built like a runner. I simply want to see how far I can go in 24 hours.

A bit about me, I’m 43.5 years old, 5’11" 207 lbs with a small spare tire and decent muscle mass. I was diagnosed Type 2 in May and immediately attempted a ridiculous fasting and keto adaptation regimen and failed. So then I resorted to Ozempic and I absolutely hate the way I feel on it so I’ve decided to dive back into keto. I ran 189 miles this fall, not as much as I wanted but that’s mostly because I wasn’t consistent and didn’t follow a training plan.

What makes this interesting as I’m recently back on Keto after a failed attempt earlier in the year. And although I’m not “untrained” by any means, my running hasn’t been consistent enough lately to see improvements in my 5k times. Which is fine, because now I have a goal and will hunker down to get those miles in consistently moving forward.

I went out today and ran a 5k (see image below), logged a 12:14 mile pace which is considerably slower than I’m used to, but I’m not terribly worried as this was my first “carbless” run and the wind was blowing around 25 mph. My plan is to keep slugging along at Zone 2 for January and February tom hopefully become fat adapted while I slowly build my base. Then in March, I will throw in some speed and hill workouts to prep for the race.

As to fueling strategies for the race, I have no idea how I will handle that yet, but then again I have 22.5 weeks/ 158 days until race day so there’s plenty of time to test methods out during my long runs each weekend. Anyhow, I’ll probably keep posting here with updates so y’all can follow along if you’re interested.


#2

Oh I am very much interested! :smiley: I just do some little walks and mini runs this far so I can’t test what I could do… Maybe one day I run a marathon, it’s not a big deal, after all but I need to start taking things seriously already for that to happen. My body isn’t into sugar and I don’t want a great pace so I am sure a mere marathon (or half if I chicken out/figure running isn’t for me, after all) doesn’t require much, good meal the previous day, maybe a little emergency food and some water, that’s it… I never want to do an ultra, either running or hiking… But I am very curious about people who do it especially on keto!
Even my (high-carber) SO (he is the runner in the family if anyone) haven’t run more than a half-marathon yet and he did that without food or water (it wasn’t ideal but he forgot, normally he runs without water as the distance isn’t great and he doesn’t need drinking all the time like I do. I would have noticed the lack of water bottle in the first half km, most probably)…

Good luck!!!


(Bob M) #3

You might want to listen to Zach Bitter’s podcast.

He is keto most of the time, but adds in some carbs when training a lot.


(Peter - Don't Fear the Fat ) #4

I don’t know about Ultra but I bet the T2 will fade away when your low enough carb.
Personally I felt great after 3 weeks and HbA1C was normal after 3 months


#5

Your doc had you following the diabetes dose increasing schedule I’d assume? In the event you go back, doing that is what gives people all the GI issues and makes them feel like hell. When it’s for fat loss, never increase the dose until it stops working.

Plus, if you were paying anywhere near retail, that much more of a reason to stretch it out! I don’t even REMOTELY pay what it costs, and I’m still cheap as hell that way!


(Robin) #6

I’m hoping @Alecmcq will chime in here… running is his jam


(Alec) #7

Hansel
I have been carnivore for 3 years now, and I am a runner: never completed an ultra or a marathon, but I am in the Canberra Marathon in mid-April. My HM PB is just under 2 hours, which I did a couple of months ago. All my running is fasted, my normal diet is carni, and I never eat carbs for fuel on runs, however long they are. Longest runs I have done in training have been around 36k.

Some questions and comments for you:

  1. What is your planned event and how far is it? You mentioned a 24 hour race? Is it simply go as far as you can in 24 hours?
  2. If you are planning to do it carbless, you must be well fat adapted. How long have you now been keto? I think you need a minimum of 6 months on strict keto/carnivore to be truly fat adapted for long distance events.
  3. You need to get your body used to running on fat… my recommended approach is fasted long runs ie get out the door early in the morning with no breakfast and no gels and no intention of eating anything. If you feel like you are bonking in any way at all, it’s a signal you are not yet fully fat adapted. Your long runs should be nice and slow, but you should feel steady energy throughout the run. You should feel a big difference between your legs getting tired vs your body running out of energy. They feel different, and you need to learn the difference.
  4. You need to make sure you are regularly taking on fluids and electrolytes/salt, especially on long runs.
  5. Recovery is important: you need to fuel up with good keto/carni food after big efforts: remember your body will use the protein to rebuild and repair, and it will use the fat for fuel. Get good sleep! Repair is much faster when you are asleep!
  6. Your training plan sounds OK, but I would not worry too much about speed sessions. Ultras are all about endurance and little else. I would focus on zone 2, build your volume gently, and also focus on not getting injured (part of the reason I suggest to not go hard on the speedwork, which is much riskier injury-wise).
  7. You should consider whether you want to fuel up with carbs during the race. If you do, you need to practice it on long runs. My personal preference is to not eat carbs at all. I run on fat.

Best of luck: comments and questions always welcome!
Cheers
Alec


(Bob M) #8

I’ve been wondering about this. I think there are two mechanisms, one using protein and one using fat, to get glucose. Consider the following conclusion from what is an incredibly complex paper:

This is the paper:

I started looking through this, but it would take me a solid week of reading just to grasp part of it.

It has tons of info in it. For instance, I thought that glucagon was a mirror image hormone to insulin: when insulin went up, glucagon went down; when insulin went down, glucagon went up. And while that’s somewhat true, check this out:

I don’t even know what to make of that.

But I’m wondering if there are differences in people so that some have a better pathway for glycogenolysis and some have a better pathway for gluconeogenesis. This would explain a lot, such as why some people prefer high fat (they process fat using glycogenolysis better than protein through gluconeogenesis) and some prefer higher protein (they process protein through gluconeogenesis better than fat using glycogenolysis).

I saw someone who remarked that her doctor (or whoever she was seeing) recommended a higher carb intake, thinking that the woman was using protein to create glucose, and higher carbs would provide glucose while limiting protein usage for that purpose. At first, I thought this was wrong, but if you’re not eating that much protein and also possibly have worse gluconeogenesis using protein, maybe that’s true?

Unfortunately, I know of no way to test any of this. If I’m better at converting protein to glucose than someone else, how do I test this?

I did hear someone who was trying to get ketone levels up on people for cancer say that two people eating the same high-fat diet can have wildly different ketone levels, and I’m wondering if the possible differences I’ve outline above are one reason why?


(Robin) #9

Thanks for chiming in, McQueen, Alec McQueen.
Knew I could count on you.