In today’s journal club we’re taking a closer look at ketones by focusing on a paper from 2020 titled “Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review” Let’s jump in.
Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review
To start with, our paper on ketones is a review, meaning rather than presenting new research data, it instead attempts to clarify the potential benefit of ketone supplementation by examining the existing research on ketones.
Let’s start with a few introductory details providing context on the roll of ketones in sport.
Ketones in Context
Why ingest ketones to start with?
Athletes ingest ketones to provide an alternative energy source during exercise in an attempt to spare endogenous (on-board) carbohydrate stores. The more carbohydrate you conserve during exercise, the more you’ll have in reserve to fuel your most intense efforts, ideally at the end of a race when you’re trying to win.
Would a ketogenic diet be better for this purpose?
While a keto diet does increase fat utilization during exercise, it also limits carb utilization at the highest intensities. In a practical sense, a keto diet seems to limit how hard you can go, something we’ve covered in this post.
So what’s the point of ingesting ketones, I’m confused?
Ingesting ketones is the sports nutrition equivalent of having your cake and eating it to. The goal is to use ingested ketones as an energy source during exercise, without needing to restrict carb intake prior to exercise (i.e. compromising your available glycogen stores and throttling high intensity effort).
But Do They Work?
With that context as a backdrop, let’s take a look at what this paper had to say about whether or not ketones actually work.
The Punch Line
Of the studies analyzed in this review, three reported positive, ten reported none, and three reported negative effects on performance when utilizing ketone supplementation during exercise.
In short, the larger body of research is inconclusive as to whether or not endogenous (ingested) ketones improve performance.
If after reading this paper you decided to avoid ketones and focus your time and energy on other proven nutritional strategies, you’d be making a good call.
Ride Basic: A Minimalist Guide to Maximize Your Cycling
Whether you’re a beginner eager to complete your first fondo, or a seasoned pro aiming to refresh the foundational principles of long-term cycling success, this time-efficient guide offers invaluable insights into why and how you can Ride Basic.
But I Wanna…
If you really want to give ketones a shot and test them for yourself, here are a few guidelines.
Cover the sports nutrition greatest hits before dabbling with unknowns like ketones
Here’s a nutritional checklist you should master before spending the time or money pursuing ketones.
- Follow a high-carbohydrate availability diet
- Ensure adequate protein throughout the day
- Strategically utilize caffeine in training and competition
- Experiment with beet juice
If And Only If
After you’ve checked off the items above, here are a few recommendations for increasing the odds that ketones might work for you.
1: Use Ketone Esters
The review article highlights four different types of ketones used in current research.
- Ketone monoester
- Ketone diester
- Ketone precursor
- Ketone salt
Of these four, ketone esters look to offer the best shot at improving performance. In simple terms, if you’re paying for a ketone product, stick to one containing ketone esters.
2: Practice
Ketones can cause significant GI distress. Make sure to ingest them during training in the months leading up to an important event to know exactly how you’ll tolerate them.
3: Get Receipts
Take notes regarding your experience with ketones. If you plan to spend time and considerable money investigating how they impact your cycling, keep any receipts (in the form of race results, ride data, segment PR’s, or lowered RPE) that offer evidence of improved performance.
These receipts can help to maximize any potential placebo effect, or give you the evidence needed to ignore the ketone hype and save your money.
References
Margolis, L. M. and K. S. O’Fallon (2020). “Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review.” Adv Nutr 11(2): 412-419.