Episode 54: Brianna Stubbs talks about ketone esters and their application in sport

// Jan 2, 2018

Late in 2017, a San Francisco startup company brought one of the commercial ketone esters to market. Today’s episode features an interview with a scientist and world-class athlete who has spent the past year helping develop and rollout HVMN Ketone, an FDA-approved drink that promises increased athletic ability as well as heightened focus and energy.

Dr. Brianna Stubbs earned her PhD in biochemical physiology from Oxford University in 2016 where she researched the effects of ketone drinks on elite athletes. During Brianna’s collegiate athletic career, she won two gold medals while representing Great Britain at the World Rowing Championships. She first made international news when as a 12-year-old she became the youngest person ever to row across the British Channel.

Brianna graduated from Oxford’s Pembroke College with a BA in preclinical sciences with the idea of becoming an MD.  But after spending a year working as a research assistant helping to investigate the effect of exogenous ketones on human performance, she decided instead to pursue her doctorate in biochemical physiology and investigate how ketone compounds might be applied in a sporting and healthcare setting in the future.

While at Oxford, she worked alongside Dr. Kieran Clarke to develop a novel ketone monoester that has been shown to improve exercise performance in endurance athletes. She also was a member of the Great Britain Rowing Team and in 2016 become the World Champion in the lightweight guadruple sculls. Brianna’s time at Oxford gave her a unique opportunity to combine her scientific interest in sports physiology and metabolism while also competing at an international level.

Brianna moved to the United States in June of 2017 to work at HVMN and help bring the company’s ketone ester to market.


HVMN website:

Mark Mattson STEM-Talk:


Mice and ketones cognition:!po=10.1064

Owen and Cahill:

Oxford ketone study:

Glycogen re-synthesi and ketones:

Ketones, glycogen and mTOR:

Caryn Zinn:

Ketone esters vs ketone salts:

Acetoacetate paper:  

HVMN online fasting community:

Show notes:

3:52: Ken and Dawn welcome Brianna to the show.

4:07: Dawn congratulates Brianna on bringing one of the first ketone esters to the commercial market, and asks Brianna to provide some background that led to the ketone ester launch.

5:31: Ken comments that the HBMN ester has been approved by the FDA as “generally recognized as safe,” or GRAS. He then asks her to expand on what this means in terms of human use and to expand on the value of the GRAS status.

6:31: Dawn asks Brianna what sparked her interest in science.

7:18: Ken comments that he heard Brianna was seven years old when she ran her first race, and that she ran so hard, she made herself sick. He asks if this is true.

8:16: Ken says that Brianna’s father was the one who got her interested in rowing, and when she was six years old, he signed her up for the first rowing race across the Atlantic Ocean. Ken asks if it’s true that he had never rowed before.

10:21: Dawn comments that Brianna used to run and row with her father as he trained for these races, and then when she was 12 years old she rowed across the English Channel, becoming the youngest person to ever do so. Dawn asks how this came about.

11:59: Dawn asks what Brianna’s mother was doing while she and her father were off rowing across the English Channel.

12:41: Dawn says that Brianna won her first international rowing event when she was 16, and then at 18 she won a silver medal at the junior world championships. She then asks Brianna’s to describe her training schedule as a teenager.

13:44: Ken asks Brianna what it feels like to be the best in the world at something after winning a gold medal in rowing at the 2013 and 2016 world championships.

16:32: Ken says that as a rower, Brianna mainly competed as a lightweight. He then asks what this meant in terms of preparing for competition from both a nutritional and training standpoint.

18:18: Dawn comments that the problems associated with excess training stress and inappropriate energy balance in female athletes were previously called the female athlete triad, but it has now been renamed relative energy deficiency in sport (RED-S). She then asks if Brianna experienced any physiological issues associated with competing as a lightweight athlete and if she saw this in any of her male colleagues.

20:35: Dawn asks Brianna if she has any thoughts on how coaches, nutritionists, and sports scientists could better support their athletes to prevent these issues.

22:39: Ken says that it was during this time, when Brianna was at Oxford, that there was a study being done on the effects of ketone esters on rowers. He then asks how Brianna became directly involved in the study.

23:51: Dawn asks why Brianna chose to postpone her medical school training to devote more time to researching ketones.

25:04: Dawn says that she understands that the CEO and a team from HVMN visited Oxford and that Brianna sort of invited herself to dinner and convinced them that they needed to hire her to roll out the ketone ester. She then asks if that is how Brianna ended up in San Francisco.

26:52: Dawn asks what Brianna’s first year in the states has been like.

27:40: Dawn says that a bottle of the ketone ester provides 25 grams of beta-hydroxybutyrate, one of the ketone bodies that the body naturally produces during a fast or period of starvation. She then asks Brianna what happens after someone consumes a bottle.

29:32: Ken asks Brianna if she has given any thought to possible consequences of supplementing with only beta-hydroxybutyrate. He then says that it has occurred to him that there might be a reason why the liver produces roughly equal amounts of acetoacetate and beta-hydroxybutyrate.

31:34: Ken says that looking back on the Cahill study, he can’t imagine proposing a study like that to an IRB now.

32:01: Dawn comments that the work Brianna was doing with Dr. Clark suggests that drinking ketones alongside a high-carb meal deliver a powerful performance boost. She then asks Brianna if the carbs are necessary to get the full performance boost of the supplement.

32:56: Ken says that state, where there is high carbohydrate availability and high ketones, does not seem like something that would naturally occur and asks if Brianna has any thoughts on this.

33:47: Ken says that you can imagine sparing the glycogen stores for when you really need them would be a great advantage in many sports, as most sports are both aerobic and anaerobic.

34:18: Dawn asks if ketone esters are best utilized as a training aid, as opposed to being acutely administered before an event.

36:03: Ken says that there is evidence that the HVMN ketone ester improves athletic performance. He then asks Brianna about its effects on cognitive performance.

37:10: Dawn asks Brianna to talk about some of the animal studies that are being conducted on ketone esters and their impact on physical and cognitive performance.

38:37: Dawn asks Brianna to explain the difference between ketone salts and ketone esters, and to also give an overview of what the advantages and disadvantages are for each.

41:56: Ken asks how Brianna envisions people using the ketone esters as part of their nutrition plan for a multi-day race.

42:55: Ken asks Brianna if there has been a study to look at the effects of chronic ketone ester administration on performance.

44:27: Dawn asks Brianna to discuss the study in cell metabolism that was published last year that looked at ketone metabolism in elite athletes.

47:15: Dawn asks how Brianna blinded people to which was the ester and which was not during these studies, since the ester tastes bitter.

48:57: Ken asks if it would be feasible to put the agents into capsules to avert the possible confounding effects of distinguishing the rather unique taste.

49:55:  Brianna believes there are important factors in running a successful and accurate sports science study.

53:00: Brianna discusses where ketones fit in the hierarchy of fuel selection during exercise.

55:53: Ken says that the terminology, ketone and ketone esters, are not synonymous, and asks Brianna to give an overview.


57:31: Dawn asks Brianna if administration of ketone esters in the context of moderate carb intake overcomes the alleged problem of reduced PDH activity associated with ketogenic diets. She then asks Brianna if she has measured PDH activity.

58:06: Ken asks Brianna if you could, by use of the ester for an athlete that was in ketosis, have the best of both worlds.

1:00:07: Dawn says that ketone supplementation has a lot of potential to improve the performance of elite athletes. She then asks Brianna if weekend warriors or average recreational athletes can benefit from ketone supplementation.

1:01:21: Ken discusses a study recently conducted in Australia which reported that an acetoacetate diester slightly decreased performance in elite cyclists.

1:04:16: Ken comments that the authors’ speculated that the observed performance decrement was the result of elevated acetoacetate levels, which he noted, does not make sense.  He also noted that all of the study participants experienced GI distress which could easily have accounted for the performance decrement.

1:06:29: Dawn asks Brianna if she thinks this study will further confuse the topic of ketone supplementation.

1:07:37: Ken says that science and religion are two different things, and that particularly in nutrition science and topics related to nutrition, it is an emotional hot button, and people get all spun up about it.

1:08:54: Ken discusses again how many sports are a mixture of aerobic and anaerobic work. He then asks Brianna how athletes will use exogenous ketones in sports with varying degrees of intensity.

1:12:39: Ken comments that it is where the ketogenic diet will have the largest effect for the aging population, both in terms of general wellness and signaling effects, with respect to avoidance of sarcopenia.

1:12:51: Brianna talks about how athletes who are already on a ketogenic diet will use ketone esters.

1:13:47: Ken discusses the increase in BDNF after exercise and a study by Sleiman et al. that showed that HDACs inhibit the production of BDNF. Also, that beta-hydroxybutyrate inhibits HDACS, which would likely increase the production of BDNF. He then asks Brianna if she has any thoughts on whether exogenous ketone ester, such as the HVMN product, might also elevate BDNF.

1:16:00: Ken says that we know that the endogenous ketones have powerful signaling functions, but one of the most fascinating questions is about which of those the ketone ester will provide equivalent or better.

1:17:50: Ken says that it is possible to have high ketone elevations with the ketogenic diet, but it makes it difficult for the people doing the study.

1:22:41: Dawn says that it was noted in a recent paper from a group at UC Davis that ketones, and specifically beta-hydroxybutyrate, potentiated mTOR-1 signaling in skeletal muscle. She then asks Brianna if there is reason to believe this occurs in other tissues or organs of the body, where a potentiating mTOR might not be welcome.

1:23:20: Ken says that they found that it was tissue specific, so the level in the liver was not elevated in that study.

1:24:55: Brianna talks about the public’s response to the launch of the HVMN ketone ester, and gives a rundown of common questions people have been asking.

1:27:51: Brianna shares what her diet is like now that she has retired from competitive rowing.

1:30:42: Ken comments that Mark Mattson discussed intermittent fasting on STEM-Talk on an earlier episode.

1:31:13: Dawn comments that it seems as though most researchers also have a social media presence today, allowing people to collaborate more. She then asks Brianna if she is active on social media.

1:34:02: Ken and Dawn thank Brianna for the interview.