What are they and do I need them?
In endurance sport, recovery, fueling and hydration can make or break our training progress and race day success. So far, I haven’t said anything you likely don’t already know.
But, here’s something you may not have heard of: ketone esters, which is a relatively new, potential performance enhancer that has gained the attention of researchers, coaches and athletes. Popular brands for this supplement include KetoneAid and KetoneIQ. If you haven’t heard of ketone esters – you aren’t alone. This supplement is pretty new to the scene, but it’s gained enough attention that I’ve fielded a variety of questions from athletes. So, I did some digging to learn more about it, and to provide science-backed information that can help us make decisions about whether or not this is something we should all be taking – or leaving.
In this post, I’ll cover some of the basics regarding what ketone esters are, and why some athletes may choose to take them (and shell out a pretty penny in order to do so). Since this product is somewhat new to the public marketplace, let’s start with the what.
What are Ketone Esters?
Ketone esters are a specific type of exogenous ketone, which means they are not produced within the body. Instead, they are taken orally. They are taken in order to increase ketone levels in the blood. You may be familiar with the ketogenic diet, which is a highly restrictive diet that aims to produce the same outcome. The trouble with the ketogenic diet for endurance athletes is that our body is highly reliant upon carbohydrates for our healthy functioning and performance. So restricting carbs is not good for us.
That has led to an exploration of whether or not ketone supplementation would have any benefit for athletes. The ester variant is the type of exogenous ketone most readily absorbed by the body, and as such, the most effective and recommended in the research.
Esters differ from other types of ketone options, such as ketone salts, primarily because esters have been demonstrated to be more effective in raising ketone levels in the blood. On the marketplace, the esters are also a lot more expensive than other variants, due to this claim of more increased effectiveness.
Ketone esters are taken orally, and they are sold as liquids or powders. The taste is very bitter. The product works best when taken after intensive exercise (either duration or intensity) and before bedtime.
Ketone Ester Benefits
Given the high price and bitter taste of this product, you are likely wondering: why would I take them?
Generally speaking, ketone esters provide benefits, such as:
- Improved cognitive function
- Reduced inflammation
- Increased endurance and time to exhaustion
- Enhanced recovery periods
Of these cited benefits, the recovery aspect has found the most traction, in my opinion. More specifically, during periods of functional overreaching, we push our bodies hard either in terms of volume or intensity – or both. This is a necessary part of creating new fitness, but it comes with risks, including fatigue, increased injury chance, and over-training or nonfunctional overreaching. Poffe et al. (2019) found that ketone esters can provide a measurable benefit for accelerating recovery and adaptation. Said differently, by taking this supplement, you support the speed and depth of your body’s ability to absorb that training – while reducing some of these risks.
In a 2023 study, Poffe and his colleagues found that the greatest benefits of ketone esters is during overload training, and not during regular bouts of training. This study found that ketone esters improved muscle capillarization, increased naturally produced erythropoietin (a.k.a., EPO), and improved muscular endurance.
I have to be honest: my bullshit meter goes off when I hear such grandiose claims for a supplement’s benefit. And, to be clear: the research is on the new side, so the samples are not universal, and there are caveats for who this will and won’t work for.
Should You Use Ketone Esters?
In an effort to educate myself about this supplement, I’ve spent a good amount of time reading through various studies and popular press articles, and listening to popular press podcasts on this subject (some of which I’ve listed below in the references section). Based on this learning, I can offer you some advice about whether or not this supplement is something you need to add.
First, ketone ester supplements are expensive. The minimum effective dose is to take about 25 grams daily after bouts of intensive exercise (i.e., overreaching periods), and before sleep. The rough estimate on cost for this dosing is around $200-$300 per week. And, to get the full benefits of this, you’d likely be taking the supplement throughout a high build cycle – so anywhere from 6-8 weeks.
I know what you must be thinking: surely that amount must be a typo. I assure you it isn’t. So, I’ll type it again: $200-$300 per week x 6-8 weeks. OUCH.
Second, there is evidence to suggest that training must come first. As with all “magic pills,” there is no substitute for doing the right work. A review study by Evans, Cogan & Egan (2017) found that ketone ester supplementation is most beneficial in highly trained individuals, who have the physiological infrastructure to take up and use the ketones. There was limited benefit found in newer athletes or in recreational athletes, with lower training loads.
Third, ketone esters taste terrible. I’ve read this pretty consistently in the more popular press descriptions. Beyond the taste, they can create GI distress. This is something to consider if you have a sensitive stomach.
My overall advice:
Ketone ester research is on the newer side of the spectrum. For every study that claims some benefit, there are other studies that question that benefit. That being said, the recovery benefit seems to be the most promising possibility. In this vein, I recommend following Dr. Chiel Poffe who is at the front edge of this research and working to produce more knowledge about KE for both elite and recreational athletes.
Given the state of the research and the exorbitant cost, I’m not convinced this supplementation is worth the charge unless you have exhausted every other 1% detail. This means maximizing your recovery through traditional and proven methods, fueling and hydrating every workout like clockwork, eating a nutrient-dense daily diet, completing 99-100% of your training, and so on.
If you are doing all of these 1% details to a “T”, and your goal is to hit the podium, qualify for a major event, or become a professional, you can discuss this supplementation strategy with your coach and your doctor. All supplements come with risks, so before you try anything, you need to speak with your doctor to discuss your specific situation and any potential health risks that may come.
Remember though: there are no magic pills that will bring us to our big dreams. It is the combination of doing the right work, and minding all the 1% details that add up to 100% of your success.
References
Evans, M., Cogan, K. E., & Egan, B. (2017). Metabolism of ketone bodies during exercise and training: physiological basis for exogenous supplementation. The Journal of Physiology, 595(9), 2857–2871. https://doi.org/10.1113/JP273185
Evans, M., McClure, T. S., Koutnik, A. P., & Egan, B. (2022). Exogenous Ketone Supplements in Athletic Contexts: Past, Present, and Future. Sports Medicine, 52(Suppl 1), 25–67. https://doi.org/10.1007/s40279-022-01756-2
Koopcast. Ketones for Ultrarunning with Chiel Poffe PhD. https://podcasts.apple.com/us/podcast/ketones-for-ultrarunning-with-chiel-poff%C3%A9-phd-koopcast/id1489494447?i=1000613478568
Pinckaers, P. J., Churchward-Venne, T. A., Bailey, D., & van Loon, L. J. (2017). Ketone Bodies and Exercise Performance: The Next Magic Bullet or Merely Hype?. Sports medicine (Auckland, N.Z.), 47(3), 383–391. https://doi.org/10.1007/s40279-016-0577-y
Poffé, C. et al. (2023). Exogenous ketosis elevates circulating erythropoietin and stimulates muscular angiogenesis during endurance training overload. The Journal of Physiology, 601(12), 2345–2358. https://doi.org/10.1113/JP284346
Poffe, C. et. al. (2019). Ketone ester supplementation blunts overreaching symptoms during endurance training overload. The Journal of Physiology, 597(12), 3009-3027. https://doi.org/10.1113/JP277831
Poffé, C., Ramaekers, M., Bogaerts, S., & Hespel, P. (2020). Exogenous ketosis impacts neither performance nor muscle glycogen breakdown in prolonged endurance exercise. Journal of Applied Physiology, 128(6), 1643–1653. https://doi.org/10.1152/japplphysiol.00092.2020
Sansone, M., Sansone, A., Borrione, P., Romanelli, F., Di Luigi, L., & Sgrò, P. (2018). Effects of Ketone Bodies on Endurance Exercise. Current sports medicine reports, 17(12), 444–453. https://doi.org/10.1249/JSR.0000000000000542
TrainerRoad Podcast. Ketones and Recovery with Dr. Chiel Poffe. https://www.youtube.com/watch?v=Ogekfdb2aXo