Is Keto Good For Runners? Let’s Find Out

When it comes to anything related to fitness, there are people out there who want to take things beyond exercising as a hobby and for simple wellness and turn it into an actual lifestyle.

Running as a lifestyle means at some point, runners will have a special diet to help them boost running performance, and many have been considering how keto fits into all of this.

Is the Ketogenic diet a good diet to pair with running? Read on to find out.

What is the Ketogenic diet?

In fitness, the ketogenic diet is a type of diet that wants to achieve a state of ketosis, a metabolic condition where the body runs on stored fat instead of glucose stores for energy.

Ketosis is like a fire inside of us that only ignites and burns with fat, and it only happens when you are really low on glucose – pretty much fooling our body into thinking there’s a famine. Because of how ketosis works, it would explain why the ketogenic diet essentially takes as much carbs out of your diet and replaces them with fat and moderate amounts of protein. [1]

In a sense, you can also say the ketogenic diet is also more efficient than traditional diets because you don’t need to eat that much food to have energy. Fat is quite calorie dense, more than twice per gram as carbs and protein, so it would make sense to be in keto if you’re after energy efficiency.

Is the Ketogenic diet strict?

Many of the benefits of the ketogenic diet revolve around weight loss among other things. The only catch is following a rather strict dietary guideline based on total macro intake, with the majority of your carbs coming from fiber.

The ketogenic can be either strict or loose when it comes to what you can eat, depending on what you’re used to eating to begin with.

If you’re used to eating meat, the diet shouldn’t be too difficult to adapt. If you’re used to eating vegetables, you have to start considering total fiber and not just carbs. If you’re used to eating fruits, candies, cakes, and other sweet foods, you’re going to see the diet as mental torture for the first week or two.

Keto and Running

Regardless of how strict a diet is, there will always be athletes out there who want to follow an eating guideline if it can result in better performance. Runners are among the most prominent athletes who tend to be quite picky with their fuel solely because of how our energy metabolism works, with the body preferring to burn glucose over fat, and it burns glucose really fast for energy.

Runners naturally prefer carbs because running really burns a lot of carb stores fast. Runners don’t want to end up “gassed” mid-run, so they tend to eat really heavy before a big running day or event, with most of their food in carb form. This also explains why the term “carbo loading” and “running” almost always belong in the same sentence.

If runners require a lot of carbs for fuel, should they even bother trying a ketogenic diet?

As with anything health and performance related, the answer to whether runners would thrive on keto is “it depends.” Before we get to the answer, let’s first define the two types of runners: Long distance runners and Sprinters.

Long distance runners

Long distance runners are those who regularly participate in half-marathons or ultra marathons. Their bodies are built specifically to be as efficient when it comes to energy storage and usage. They can run for hours at a constant speed without feeling fatigued or sore, but they do require a lot of energy stored for use. This is also why many times halfway through a run, some runners “fuel up” with carb gels or running gels because they feel their bodies running out of carbs to use.


Usain Bolt
Image courtesy of

Sprinters are those you see doing short distance dashes on TV. Sprinters are often more “muscular” than their long distance counterparts because their bodies are built to go from 0-60 in a few seconds. Because of this, they need immediate and fast access to energy, and they also need a lot of carbs, though they often stick to carbs that are easier to digest than the fibrous ones.

Usain Bolt is the most popular sprinter today, and his diet consists of a lot of carbs. He is quoted to have a regular diet consisting of “eggs, pasta with a side of chicken breast for lunch, and Jamaican dumplings or rice and peas with pork and roasted chicken for dinner.”

So, is keto any good for runners?

The hard answer to this question, on the basis of running performance, is unfortunately no. [2]

You can always use the ketogenic diet for general running, but it’s not something you would want to rely on during competition. If you never need a huge burst of energy, keto is alright.

Unfortunately, many runners need that burst of energy and carbs are the easiest way to access them. Not to mention how fat is considered low-combustion fuel, so it takes a lot more to burn fat than glucose.

Sprinters often will not benefit from the ketogenic diet, but distance runners might since studies have shown that the body taps into fat stores (ketones) about two hours into their run or after the body no longer has carbs to burn. The same applies to other endurance sports. [3]

The caveat is; distance runners need to be first acclimated to ketosis to get the most out of the ketogenic diet in their runs, and this can take more than two months even with strict dietary discipline.


The ketogenic diet is an eating style that wants to capitalise on the body’s natural ability to run on fats instead of carbs. Many proponents “go keto” due to its many benefits, primarily for body composition and weight loss. Runners can also try the diet, but it can be tricky doing a balancing act between what is good for running performance and what is good for metabolic efficiency.


  1. Castro AI, Gomez-Arbelaez D, Crujeiras AB, et al. Effect of A Very Low-Calorie Ketogenic Diet on Food and Alcohol Cravings, Physical and Sexual Activity, Sleep Disturbances, and Quality of Life in Obese Patients. Nutrients. 2018;10(10):1348. Published 2018 Sep 21. doi:10.3390/nu10101348 Available at [Last accessed 16 April 2021]
  2. Volek JS, Freidenreich DJ, Saenz C, Kunces LJ, Creighton BC, Bartley JM, Davitt PM, Munoz CX, Anderson JM, Maresh CM, Lee EC, Schuenke MD, Aerni G, Kraemer WJ, Phinney SD. Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism. 2016 Mar;65(3):100-10. doi: 10.1016/j.metabol.2015.10.028. Epub 2015 Nov 2. PMID: 26892521. Available at [ Last accessed 16 April 2021]
  3. Zajac A, Poprzeczki S, Maszczyk A, Czuba M, Michalczyk M, Zydek G. The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists. Nutrients. 2014 Jun 27;6(7):2493-508. doi: 10.3390/nu6072493. PMID: 24979615; PMCID: PMC4113752.  Available at [Last accessed 16 April 2021]
Robert Rivera
Robert James

A graduate from the University of Santo Tomas, Robert writes about sports supplements, nutrition, health & fitness and medical topics. Robert is a former Research Scientist and holds a degree in Food Science, Technology and Nutrition. Robert regularly shares his scientific knowledge and research-backed content on health authority websites, various podcasts and social websites including Quora.

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