© Copyright – 2019 – Athletics Illustrated

Much has been made in endurance sports circles about the apparent training benefits of consuming exogenous ketone esters. It is well-documented that six competitive teams that participated in the Tour de France admitted to drinking the supplement throughout the 2018 and 2019 tours. The product is gaining notoriety.

Currently, the question isn’t so much whether ketone esters benefit endurance athletes, but rather how.

Firstly, let’s tackle being in a state of ketosis, naturally. Getting into a state of ketosis due to fasting or reducing carbohydrate intake will require dieters to eat high ratios of fat, moderate protein and very low volumes of carbohydrate. Ratios of macronutrients in the diet could look similar to this:

60% fat
30% protein
5% carbohydrate
5% fibre

Author at 2K mark in Victoria, BC Clover Point Park Run. Photo credit: Joseph Camilleri.

The above ratios basically flip the typical North American diet upside down or perhaps right-side up. Currently, carbohydrates, especially refined carbohydrates, make up the bulk of the average person’s diet in North America and other jurisdictions like the UK, parts of mainland Europe and Oceania. Saturated fats, long and wrongly considered unhealthy, make up the least of the four macronutrients (fat, carbohydrate, protein, and fibre). Meanwhile, there are three apparent epidemics that are related: obesity, type 2 diabetes, and coronary artery disease.

Being in a state of ketosis will help those who carry excess weight drop pounds and inches rapidly by primarily jettisoning excess water that one retains from eating (and not burning off) excess refined carbohydrates as well as the benefit of no longer storing un-burned, if you will, carbs as fat.

For every gram of carbohydrate that is stored as fat, 2.5 grams of water is retained as well.

Food products made with refined sugar or flour as well as potato or corn starch for example bread, wraps, doughnuts, candy, cake, cookies, pop, croissants, bagels, some crackers, energy drinks, beer, pizza crust, and most desserts are verboten. Also, foods containing a high level of carbohydrate naturally like popcorn, potatoes, fruits, bananas (bananas are berries), juices and most root vegetables, are going to cause one to store carbohydrates as fat as well as retain water unless it is burned off through vigorous physical exercise.

To maintain a low-carb diet, there are no industry standards, however, fewer than 50 grams per day is a popular number used, however, <100 grams can be considered low-carb to some.

The following common foods and beverages are high in sugar. Their carbohydrate content is listed to the right:

Product size Carbs grams (g)
Coca Cola 330ml 39g
Bagel 1 40-50g
Caramel Macchiato Large 40g
Big Gulp 30 oz. 47g
Cold cereals bowl 30-50g  (w/out milk, fruit or yogurt)
Ice Cream 100g 24g
White bread 1 slice 13g

Adding up a few of the items on the list above will easily top a low-carb diet in a single meal.

There is preliminary information suggesting that exogenous ketone esters may benefit cognitive function as well as aiding weight loss. Apparently, MCT oil, MCT powder and coconut oil like ketone bodies may also cross the blood-brain barrier and in so doing maintain neurovascular integrity. There is some potential evidence suggesting that the oils and or ketones or while being in a state of ketosis will benefit people who live with Parkinson’s and Alzheimer’s diseases as well as Dementia. More studies have to be conducted.

KetoneAid contains one of the three ketone bodies: Betahydroxybuterate. Apparently, it is the most stable of the three to send to market. Acetoacetate and acetone are the other two ketone bodies.

Ketone ester effects on endurance training:

For a direct effect on sports performance, the data is very preliminary and as Canadian exercise physiologist Trent Stellingwerff said, “There are not enough studies done yet to prove that there is a performance benefit. However, a single study thus far has shown a recovery benefit in less over-reaching symptoms during hard training. However, similar to the performance studies, it is too early, and more evidence is required, to see if this is a real consistent effect.”

Of course, quicker recovery (if it is true) could indirectly benefit performance, through the stimulus-recovery-adaption process of becoming fitter through training. Time will tell.

As expected, scientific studies on exogenous ketone ester consumption will likely be conducted on sub-elite, elite and world-class athletes. The question many recreational athletes may ask is, “how will ketone ester consumption affect my performance or recovery status?”

In 2017, according to the study, “Ketone Bodies and Exercise Performance: The Next Magic Bullet or Merely Hype?” indicated that for now, it’s all hype:

Peter Hespel, professor of Exercise Physiology at KU Leuven Belgium at the Department of Movement Sciences told Athletics Illustrated, “At present, there are no data available to suggest that ingestion of ketone bodies during exercise improves athletes’ performance under conditions where evidence-based nutritional strategies are applied appropriately.”


However, all is not lost – in case you just invested in a cupboard full.

Hespel and his research team, which includes Chiel Poffé, Monique Ramaekers, and Ruud Van Thienen, led an interesting study (the one Stellingwerff earlier referred to) with cyclists who supplemented their diet with a ketone ester (KE). Results indicate that ingesting ketones with little to no other dietary changes may attenuate some negative training effects from periods of intense volume and effort.

Below is the author’s first-hand experience consuming ketone esters for running.

Anecdotal performance report:

Athlete profile:

Age: 53
Gender: Male
Sport: Road and trail distance running
Current running-specific fitness: Modest
Height: 5’9″
Weight: 147-149 lbs


Took ten years off from semi-competitive masters-age long-distance running, primarily road racing. During that break, there were three surgeries: 2 x Haglund’s Deformity (each heel, 2009, 2010), 1 x hip replacement (right) in late 2016.

Returned to running April 2017 on a very low-volume program with a gradual increase over the following 29 months.

Currently, I am running 60-74 kilometres per week. Two gym sessions of various upper-body weight exercises as well as one or two heavy bag workouts per week. Some modest road cycling, generally an active lifestyle and I walk 10-30K per week as well as enjoy hiking.

Product: KetoneAid (ester).

Disclosure: Twelve x 60ml bottles were supplied by the company “KetoneAid” to publication “Athletics Illustrated” for review purposes. At no time will any person involved with the publication including the author be paid or reimbursed in any way for the review(s) or products by the company. The review(s) are impartial and based solely on first-person independent and anecdotal evidence. The company will not be reimbursed in any way for the supply of the product to the publication.

Ketone consumption dates: Started on June 18, 2019, through to Aug. 27, 2019, and continuing.

During 2018 and through to March 2019, the weekly volume of running ranged from as low as zero to 40K. The inability for the atrophied muscles in the leg (around surgery site) to recover from runs forced a schedule of just 1 to 3 runs per week. There was no apparent change in this program over the following 26-months.

Due to repetitive calf injuries, I was required to take complete weeks off in February, March and April 2019. I was unable to grow volume or run with intensity without suffering calf pulls and abductor stress.

During mid-June, I managed my biggest week post-hiatus with a 60K, Monday to Sunday week of training.

Since consuming ketone esters, I have had the most consistent stretch of running, injury-free. I have now run an average of 60K per week with a high of 74K and a recovery week of 45K. Although causation does not necessarily imply a correlation, the consistency of repetitive running coincided with the consumption of ketone esters and the ability to run on the atrophied leg repetitively has been a pronounced change. It is unknown if this result is coincidental or directly related.


Furthest distance run: 25K – Aug. 11, 2019.
Longest time running: 2:33 (forested run with significant elevation change and technical trail), Aug. 18, 2019.
Most consecutive days running: six, three times, June, July, and Aug.

Run work rate:

Due to lack of fitness from hiatus, a long run is kept to 18-25K (as opposed to traditional 32K+). My long-runs are currently measured by time rather than distance with the minimum being two hours.

The two-hour-plus “long run” pace is 6:00 per km (+/- 10 sec) (147 bpm +/-).
5K race pace (mostly time trials at near full race effort = 176 bpm +/-) 22:33 – 23:51 (masters pb = 17:58 at age 42).

Long run paces are at 75% +/- of 5K race pace or 4:25/6:00 per km +/-.
Heart rates: 5K = 176 bpm +/- — long runs = 147 bpm +/-.

Attenuating over reaching indication:

Six Saturday Park Runs, (5K time trials) at near full-out race effort were performed. Until the ketone ester protocol was started, this effort required two days off for muscle recovery around the surgery site. Sunday long runs of 18-25K or 2:00-2:33 were run every week without interruption after the Saturday 5K race-like effort as well as on non-race weekends. Previously, this was impossible.

Ketone ester protocol:

5ml before bed, fasted, two to three nights per week.
15ml fasted before four of the time trials.
15ml fasted before each of the long runs.
60ml – DF with 30g of carbohydrate before two of the time trials.

Dual Fuel test (60ml – DF):

Fasted, took 30g of carbs (Gu-brand gel) and then 20 minutes later, consumed one 60ml bottle of KE in *500ml of water, started warm-up 10-minutes later. The 60ml – DF test was run twice. Interestingly, there seemed to be no significant performance gain during the 5K near full-out time trials with the 60ml – DF protocol, in fact, I ran marginally slower, however, the Sunday long runs saw the fastest km splits accomplished at the end of the long run. This marked a significant change.

*No Gastrointestinal issues (GI) at any time, however, I am not accustomed to having 500ml of water in the stomach to start a run. Always run on an empty stomach.

Six 5K race efforts and six Sunday long runs:

KE 5K TT Time Long run dist. Time Fastest split
15ml 29-Jun 23:53 30-Jun 20.91 2:05:07 20th: 5:18, run avg: 5:59
15ml 6-Jul 23:28 7-Jul 21.02 2:07:55 2nd: 5:38 (purposely ran slower) avg: 6:05
15ml 20-Jul 22:33 20-Jul 20.01 2:01:52 20th: 5:42, uphill, avg: 6:05
15ml 3-Aug 22:48 4-Aug 17.91 2:12:29 Technical trail running
60ml – DF 10-Aug 22:51 11-Aug 25.06 2:28:18 20th: 5:22 avg: 5:55
60ml – DF 24-Aug 23:24 24-Aug 22.01 2:10:22 21st: 4:41 avg was 5:56
The fastest split was the second to last km 21 of 22K run at 4:42/km

Ran two-hour runs each on Aug. 18 and Aug. 20, this was impossible before June 18.

Note: On Dec. 31, ran a 5K race on a flat course in the time of 23:38. Needed the following day off, followed by a light 7K run the second day, where the heart-rate indicated that I was not yet recovered >155 @6:00+ per km.

On Jan. 27, ran a 10K road race in the time of 48:43, required nearly two full days off to attempt running again.

Interim conclusion: 7/12 bottles have been consumed. From June 18 to August 25, there was no significant improvement in 5K TT performance and there was no significant performance improvement over 20-25K long runs the following day, however, overall volume increase, which typically leads to better future performances, allowed injury-free running for the first time in over two years.

Note: The Sunday long runs that took place on the following day after time trial could have gone longer, however, I ran them:

  • fasted five of the six times (was careful not to bonk – yet).
  • temperatures were high for four of the runs (not heat acclimatized).
  • volume adaptation was kept to within 2:30:00 +/- to ensure no acute muscle injury.

Comment: There appears to be a clear recovery benefit with hard efforts and there appears to be room for extra volume growth under the protocol. Although volume has been held to <80K per week, training volume (see graph from Strava), is clearly higher and more consistent since return from decade-long hiatus.

Natural Ketosis:

During 2018, I was on a disciplined ketogenic diet. Results were typical where I experienced rapid weight loss (170pds to 140pds), and modest gain after three months (147-149). Experienced apparent untappable endurance (7-hour road cycle with almost no prior adaptation) while also suffering from debilitating anaerobic-like efforts over shorter, faster and especially steep hill work on foot. Currently, eating a low-carb/high-fat diet (LCHF) instead (almost 0 refined carbs – most carbs obtained through whole foods).

Diet during the ketogenic period:

60-90% fats
10-30% protein (too much protein can interrupt ketosis)
0-10% carbohydrates
1-5% fibre

Current diet of LCHF:

50-60% fats
20-30% protein
20-30% carbohydrates
1-5% fibre