How do exogenous ketones affect athletic performance?
H.V.M.N. Ketone Ester
There are three published studies of H.V.M.N. Ketone Ester in athletes (total n = 59). In one study, performance in a 30 minute cycling time trial (after 60 minutes of "pre-fatigue") was measured. H.V.M.N. Ketone Ester taken along with carbohydrates improved cycling time trial performance by 2.3% compared to the same amount of calories as multiple transportable carbohydrates. Blood BHB was 3 - 5 mM in all three athlete studies.
Other effects of H.V.M.N. Ketone Ester found in these studies included:
- Lower levels of blood lactic acid during exercise.
- Less use of muscle glycogen during exercise.
- One study saw faster muscle glycogen resynthesis after exercise with H.V.M.N. Ketone Ester and IV glucose. A similar study of H.V.M.N. Ketone Ester with a carb/protein drink did NOT see this effect.
- Increased use of stored muscle fat during exercise.
- Less muscle protein breakdown during exercise.
Other Ketone Esters
You may have recently seen a study of ketone esters (carried out in Australia) that looked at the performance effects of ketone esters taken before a 31 km cycling time trial. This study found that many of the athletes felt sick after taking the ketone ester and that their performance got worse. Why might this have been different to the results using H.V.M.N. Ketone Ester?
- The ketone ester used was an Acetoacetate Diester (AcAc2 ester). This is a very different compound to the BHB monoester (BHB-ester) used in H.V.M.N. Ketone Ester.
- The AcAc2 ester contains 3 "ketone equivalents": 2x AcAc and 1x racemic butanediol. BHB-ester in H.V.M.N. Ketone Ester contains 1x BHB and 1x D-butanediol. Because of differences between the esters, the blood BHB levels were much lower after the AcAc ester: ~1.1 mM compared to 3 - 6 mM in the study of H.V.M.N. Ketone Ester. This is significant if the main use of ketones is as a fuel.
- Most importantly, the AcAc2 ester had only been tried in humans a few times. There were no other published human studies of the compound. This means that the actual formulation (i.e taste, texture) of the ester had not undergone very much refinement. In the Australian study, the AcAc2 ester caused every participant GI distress. This is likely to be a HUGE confounder in relation to performance–athletes are never going to do well if they feel sick! H.V.M.N. Ketone Ester does not cause side effects like this.
- AcAc is converted to BHB by an enzyme that is reversible NAD linked and operates to achieve equilibrium. That means some AcAc is converted to BHB. This conversion USES up a co-factor called NADH. The co-factor NADH is the proton end electron donor for the electron transport chain. If you use up NADH (vs giving BHB, which generates NADH when converted to AcAc) this could negatively affect energy production in the mitochondria, and therefore, performance.
Read a non-technical critique of this study here: https://hvmn.com/blog/in-response-to-nyt
Read a technical commentary on this study here: https://www.frontiersin.org/articles/10.3389/fphys.2018.00279/full
There are two published studies investigating the effects of ketone salts in athletes (total n = 22). Performance over 4 minute cycling time trial and a 150 kJ ( ~10 mins) cycling time trial were compared between ketone salts (without carbohydrates) vs. carbohydrates alone. In the 4 minute trial, there was no change in performance, and in the 150 kJ test performance was decreased by 7%. Blood BHB levels peaked at 0.6 and 0.8 mM in these studies.
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