Fueling on a low carb/keto diet


DIS Veteran
Feb 13, 2013
Anyone here successfully run long distances (13.1 or greater) on a low carb diet? I have just started eating keto and am worried about how to fuel when I start training again. I used to use Cliff Gels, but one packet is already my daily allotment for carbs!


queen bee
Sep 23, 2013
I listen to a podcast, No Sugar No Grains, and they interview many guests who are long distance athletes (runners, ultra runners, tri's) who fuel without sugars. I am on an injury break right now, but I have done a few training rounds for half marathons while eating low carb. I would train by only fueling on fats and then on race time take some sugar to get that extra fire. I can't remember which book I read it in (Noakes or Perlmutter?) but if you train on keto/low carb but trickle in sugar during a race, you get a big burst.

When I did the 2014 WDW marathon, my food fell out of my belt right at the beginning. I don't know where the food stations were but I did not get anything to eat until after 10 miles. Then of course, everything on the race course is sugar. I am a slow runner, so I finished in 6:00 and I remember feeling pain from being on my feet that long, not passing out due to lack of sugar.

If you are truly following a keto/low carb diet, you will do just fine. Snack ideas are olives, packets or baggies of nuts or a scoop of nut butter, cheese cubes (if you are ok with dairy), or UCANN starch. Also, if you are running you may find that you can afford to have more carbs in your diet. On my running days, I could have up to 100 carbs a day and still be in ketosis. But remember that those carbs should be from vegetables.


Earning My Ears
Jan 18, 2016
I am relatively new to a low carb high fat diet, but was able to run this past NYC marathon and this past dopey marathon on it. I also complimented this way of eating with running by the Maffetone method (heart rate based method) and keeping my pace it easy and aerobic.

I loved it and it was by far the quickest way I have ever lost weight, and I mean I was losing weight and getting fit faster and more efficiently than when I was in my twenties (I'm a 34 year old man).

With that said, it is very tricky and one must be well informed and disciplined. Prepare to go paleo and cut out all bad things. I love the structure, but others who want to be more loose and free wheeling might not be as successful and might even encounter some harm.

The pros for me:
-high energy.
-can go long periods without feeling hungry
-pretty much don't use any fuel when training (I am used to training first thing in the morning in a fasted statr anyways)
-when I go long periods without food I don't get moody or get headaches
-improved my blood sugar and blood pressure
-eat food I love without bingeing or cravings (as often when I just go low fat)

-possible hormonal issues
-gut issues. Developed an avocado intolerance because I overdid it
-easy to undo all the work with a bad week of high sugar/carb intake (didn't happen during training, but it is something to consider)
-can get expensive
-might be a little more dangerous for women (seems to be more hormonal issues for women. I'm a guy but had low testosterone for a while)
-very easy to break down muscle if a healthy balance is not maintained

I suggest seeing a doctor before going on it, and getting someone experienced or certified to guide you through a program. I have read that it can be dangerous to dive into becoming fat adapted from a very unhealthy state.

I relied on books, Internet articles, and podcasts, but nothing beats having someone who can narrow in on your personal needs.


Also, along with what others above have mentioned, check out fat burning man, endurance planet, and Ben greenfield fitness podcasts.
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Earning My Ears
Jan 18, 2016
Btw, the "wild friends" packets are great LCHF alternatives to sugary gels (sunflower and honey is so good). I usually don't consume anything before I hit 20 miles and am in aerobic/MAF HR ranges, but when I do I pretty much use that or Justin's nut butter packets.