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Long Distance Running on Keto

The question I’ve been asking myself for years now is, is long-distance running on Keto possible? How? Why? When?

long distance running on keto

After over ten years of being a runner, I decided to try running a half marathon, while in the state of Ketosis…so what happened???

Keep reading to find out. ????

If you are a runner or an athlete, you have probably been brainwashed to believe that you “NEED” carbohydrates for endurance running, I was the same way.

The Myth: You Need Carbohydrates aka Glucose for Energy

I am not about to quote any studies here because frankly, there are studies to prove two sides of the equation, and my post is always based on my n=1 experiments and biohacking. With that being said, yes, I don’t disagree that carbs provide energy, but so do ketones.

If your body is producing ketones when you are in a Ketogenic state, you will have more than enough “energy” for endurance running or any athletic activity. We have way more calories of fat stored in our bodies than we do carbs and you would never burn through all of your fat stores within one race.

On the contrary, carbs get burned pretty quickly, and then, what happens? You crash and need MORE carbs. That is the vicious cycle of running on carbs.

I’ve been subscribed to Runner’s World magazine for over a decade now and in every single article about training for a marathon, or what to eat the night before they always talk about “carb-loading.” So, that is what I have done, for the past eight years or so since I got into racing.

This year, I decided to try something different. I signed up for the Cincinnati Flying Pig Half Marathon, and I wanted to see if I could run a Half Marathon on Keto. I wasn’t brave enough to try a full marathon on keto because for one; I didn’t have enough time to train for a full marathon and two, I was still stuck on the belief that I would “crash” and needed carbs to perform.

I will say I would not do this if you are new to Keto. I have been following the Ketogenic diet for almost four years (minus pregnancies and the occasional cheat days (or weeks ????) ) so my body is pretty adapted to ketogenesis.

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Running on Keto

Tips for training:

Let’s talk about how I trained to run on Keto because let’s face it; you don’t just wake up one day and decide to run 13.1 miles out of nowhere like it’s no big deal. You have to prepare your body for it, especially if it’s your first time running on fat as your energy source instead of carbohydrates.

1. Electrolytes are crucial

If you are already following a Ketogenic diet, you may already know the importance of electrolytes. However, when it comes to running on keto, electrolytes are crucial.

Why? Because you lose a lot of them during long-distance running, especially sodium. You need to be proactive about replenishing them constantly.

I made this mistake at the beginning of my training and paid for it with massive headaches that wouldn’t go away. I started taking this Trace Minerals Electrolyte Stamina supplement consistently, and they finally went away.

Not to mention, if you don’t take enough magnesium while you are running on keto, you will get awful muscle cramps. I’m talking, wake you up in the middle of the night Charlie horse cramps. Not fun. If you are experiencing this, then you are deficient in magnesium. Start taking a magnesium supplement regularly. Here is the one I choose.

If you don’t like taking supplements, you can use Ultima Replenish Powder or Zip Fizz powder. Both have the electrolytes you need and will help you with headaches and muscle cramps.

2. Get enough calories and protein

Now is not the time to start intermittent fasting or obsessing about your protein macros. You need protein to rebuild muscle, and long-distance running beats the crap out of your body to give it some extra love.

The same goes for calories; when you are training for a half marathon or a marathon you have some long training days, I’m talking 2-3 hours of running straight. You need to make sure that your body is fueled correctly with good quality fats, protein, and “carbs” from veggies.

If you are running on Keto, I would recommend you stop tracking your calories and protein and eat until you are full. You can go back to strict tracking after the race because for now; your focus should be training your body how to run on Ketones for fuel instead of reaching your protein and daily calorie goal.

3. If you feel sluggish or drained, a pre-workout is ok.

I say ok because you have to choose carefully when it comes to pre-workouts. Most pre-workout supplements are filled with sugar and other crap that they don’t even need to disclose to you.

The last thing you want if you are training your body how to run on keto is to get out of ketosis by a stupid pre-workout. Just saying.

As far as good options for pre-workout, here is what I use:

Side Note: Don’t rely on pre-workouts. You should only use them on days when you are not feeling it. We all have those days where you didn’t get enough sleep, or you drank too much the night before, so it’s ok to get a little help, so you don’t skip your training day.

Eventually, you will get to the point where you won’t need any pre-workout because your body will be so efficient in using ketones for energy. It’s a pretty fantastic feeling.

The day before the race:

1. Resist the urge to “carb load”

Ok, I am not going to lie, I was tempted to “carb load” the night before. I was nervous, after running so many races and carb-loading, how could I not binge on pasta and bread to get ready for the big day?

I will say I did have some sweet potatoes. They were my “carbs.” I figured I would quickly burn through them, and I think it was a mental thing more than anything. If that is how you are, I will recommend adding some sweet potatoes to your meal the night before a big race if you are planning on running a keto marathon or half marathon.

2. Drink lots of water

This is important because the last thing you want is to be dehydrated while running on keto. Also, not to mention, if you wait to drink tons of water in the morning (like most racers do) you will be stopping at every porter potty stop along the course, and that will kill your time.

3. Take your electrolytes religiously

Make sure that the day before the race, you don’t have any headaches or muscle cramps by taking magnesium, potassium, and sodium. Again, you can take them by an all-in-one supplement or a drink. Adding salt to your water is a great way to replenish your sodium.

4. Don’t drink too much coffee

Coffee is a diuretic, and it will dehydrate you and make you want to go pee like crazy. If you are going to drink it, have a small cup in the morning the day before the race, but not on race day. You will have enough adrenaline from the race vibes; you won’t need coffee; trust me.

Race Day Tips for Running on Keto

Congrats! You made it to race day!! Whoohooo! Are you excited? You should be because running a half marathon or marathon on Keto is EPIC!! Not many people can do it!

Morning of Race Day-

1. Breakfast should be fat and protein

After you wake up and get dressed, take some electrolytes and have a fat and protein-filled breakfast. I had the following:

  • 2 hard-boiled Eggs
  • 1 Avocado
Running on Keto
Breakfast of Keto Champions ????

That is all seriously. You don’t want to overeat because that food will be bouncing around in your stomach and you don’t want to have to stop pooping during the race.

Speaking of pooping, try to poop before the race. I know, I know, you can’t just make yourself poop, but maybe there is a particular food or drink that helps you poop? If that is coffee, then go ahead and have some but just a little. It’s better to have a bit of coffee than to have poop cramps during your race.

Drink enough water to quench your thirst but don’t chug water the morning before the race, remember, you were supposed to be drinking water yesterday.

If you have been training with a pre-workout consistently or zip fiz, it will be ok to have some the morning of the race but don’t do anything you haven’t done during your training regimen.

Now is not the time to experiment with new things. Trust me.

Time to run!

Get your mind, right. You will start getting nervous and questioning yourself, “can I run this thing on Keto?” Kill those thoughts, of course; you can! You have been training for the race on Keto, running on race day is the natural part!

2. Slow and Steady-

Don’t be tempted to zoom off at the start line with the rest of the crowd. I see this happen at every single race I’ve run. People sprint at the start line, and a few miles later, I catch up to them walking and depleted. They ran out of carbs and hit the wall.

Even though you are running on ketones and will have endless energy, you should still start slow to prevent any injuries from happening. Run at the same pace you trained at and if you want to speed up, do it during the last 5k.

3. Stop at each water stop-

Every. Single. One. I mean it. Even if you are taking a few sips, you will be losing a lot of electrolytes during the race, especially if it’s a hot day and you want to stay hydrated.

Make sure you don’t accidentally grab the Gatorade because if you do that, you will crash and burn into the never-ending cycle of needing glycogen for the rest of the race.

4. Take the gels that are offered, just in case-

On the other hand, now is not the time to let your ego get in the way. Once I reached the 6-mile mark, I saw a gel station, and I wasn’t planning on taking it, but I did grab a couple, just in case.

Look; you never know what is going to happen. What if you do crash and can’t go on anymore because you are so depleted? That is ok, and you should be prepared. Go ahead and grab some gels but push yourself to make it without them.

There was another point around the 10-mile mark that I felt like I “needed” the gels. I was so tempted to rip one open, but then I thought, “This is my brain playing tricks on me.” I didn’t physically need the gels, I was getting tired, and my mind automatically thought of an easy way out. I didn’t give in, and I am so happy I didn’t. I switched my playlist and killed those last 3.1 miles.

So, is it possible to run long distances on Keto? I am happy to say, HELL, YES!!!! Before this experience, I have heard and read about the crazy athletes who run marathons, iron man, ultramarathons in a Ketogenic state, and I thought they were some kind of make-belief super mystical human creatures.

Now, I can’t say I can compare myself to them, but I can say it feels pretty awesome to be part of that group even if it’s on a smaller scale.

Flying Pig Half Marathon
Sweet, Sweet Victory!
Flying Pig Half Marathon
Another one to add to my collection ????

In conclusion, I want to say that if you have been considering running on Keto or running a Ketogenic race, I highly encourage you to try it out. Make sure you train correctly, take your electrolytes but most of all, believe in yourself and that you can do it.

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More articles about Keto Diet:

  1. What is Clean Keto Carb Cycling?
  2. The Top 10 Supplements To Take On Keto
  3. I Tried The Slow Carb Diet For 30-Days
  4. How To Calculate Your Keto Macros

18 thoughts on “Long Distance Running on Keto”

  1. I just did two half marathons two weeks apart, both in strong ketosis. Zero carbs the night before or day-of! I didn’t even need to stop for water until mile 11, however I don’t recommend that in hind sight! Ketones are such a better fuel for this carrier unit, I’m hooked!!!

  2. I do all my training runs fasted and in ketosis (except for the weeks when I travel and indulge.) I’ve done runs of 30+ km without taking anything and I don’t feel weak or anything. Some faster marathoners will go a whole marathon without taking any gels but I think I will take some in my next marathon because I feel it will help me be faster. I’ve also ran fast 5ks and 10ks without taking carbs and I even beat my normal diet (higher in carbs) PRs. I know most people think you cannot run shorter distances on a keto diet but I’m the proof that it can be done.

  3. I am just starting to get back into running. I’ve been following a ketogenic way if eating for a few years and love it bi have seen it work well with weightlifting and now I’m excited to try it out with running. Thank you for all the info in this post.

  4. Thanks for posting this. I had read all the same things about meeting to carb load and was worried that I would never get very far with running on a keto diet. I feel much more at ease now!

  5. I’ve been on Keto for 7months now and only took up running during that time, I’m keen to train for a half marathon (I currently run to 10K) but wasn’t sure if it was possible in ketosis after having read all the pro carb loading articles!! As running is new to me I have never run on carbs! I seem to do well up to 10k, and I do surprise myself at how fast I go during interval training. I usually run before eating but as I extend the distance I will eat before a run. I wasn’t sure if I should have a nutty snack of some sort mid run, or is that not really necessary? I don’t get hungry when I run so maybe not. Thank you for the very interesting and helpful article.

  6. Hey Caroline! I think it’s great to have something with you just in case, but as I always say to my clients, just listen to your body. It will tell you what it needs! Most of us have more than enough fat stores to keep us going for a long time so you may be fine with having nothing during the run.

  7. I’m thrilled I found your post about running on keto! I’m am a new runner and am running my first 5K this Saturday and am excited to read that I will (hopefully!) be able to go even further while maintaining my ketosis. Thanks for sharing your experience and training tips!

  8. I’m thrilled I found your post about running on keto! I’m am a new runner and am running my first 5K this Saturday and am excited to read that I will (hopefully!) be able to go even further while maintaining my ketosis. Thanks for sharing your experience and training tips!

  9. Thank you for sharing practical tips.
    I’m currently working as a cleaner with 4+ hour shifts which are very physically active but needing info how to make keto work for me & my husband who often has long days of manual labour too.
    So overcoming the “need carbs” myth / realising our bodies have plenty of fat stores – especially given from a woman’s experience has been very helpful. Thank you.

  10. Thanks for the tips. I just started ketogenic diet. Before this I can do 10km in 1hr 10min. I have a Marathon coming up in 82 days. Is it bad idea to start keto and marathon training at same time? Or I should be alright as long as body can push?

  11. So I have been a triathlete for yonks, but very new to keto and this is such a new approach to racing!! Certainly going to be a massive mindshift to be make since the fourth discipline of Ironman is nutrition.. lol .. seriously though have been reading a lot about exogenous ketones especially for longer distances, any thoughts? Very odd to be going into a race with NO nutrition on you except what is already on your body .. freaking out just training fasted, despite it actually going well so far, ha!

  12. Hey there! It’s fantastic to hear about your journey as a triathlete, and it’s great that you’re exploring keto as a new approach to racing. You’re absolutely right—nutrition is often considered the fourth discipline in triathlons, especially in long-distance events like Ironman races.

    Exogenous ketones can be a useful tool for athletes on a keto diet, especially for endurance events. They can provide an additional energy source and help maintain ketosis during long races. However, it’s important to experiment with them during training to see how your body responds and to figure out the best timing and dosage for your needs.

    As for training fasted, it can be a bit nerve-wracking at first, but it’s encouraging to hear that it’s going well for you so far. Fasted training can help improve your body’s ability to use fat as fuel, which is a key aspect of keto-adaptation for endurance athletes. Just make sure to listen to your body and adjust your training and nutrition as needed.

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