How do exogenous ketones affect athletic performance?
There are three published studies that examine the impact of exogenous ketones on athletic performance, tracking 59 athletes in total.
One study found that exogenous ketones, when taken along with carbohydrates, improved athletes' performance in a 30-minute cycling time trial by 2.3%, compared to the same amount of calories as multiple transportable carbohydrates.
Another study saw faster muscle resynthesis of glycogen, the body's carbohydrate stores, after exercise with exogenous ketones and IV glucose. However, a similar study on exogenous ketones taken with a carb/protein drink did NOT see this effect. Further research is needed to understand exogenous ketones' impact on glycogen resynthesis.
Other effects of exogenous ketones found in these studies include:
- Lower levels of lactic acid in the blood during exercise.
- Less use of muscle glycogen during exercise.
- Increased use of stored muscle fat during exercise.
- Less muscle protein breakdown during exercise.
Blood BHB levels reached between 3–5 mmol/L in all three athlete studies. Recent studies have shown that too-high blood BHB levels may increase cardiorespiratory stress markers without enhancing athletic performance. This may be due to acidosis, a condition where too much acid accumulates in body fluids, affecting blood pH levels.
H.V.M.N. used these findings to develop Ketone-IQ™️, which is found in H.V.M.N. Ketone 2.0. This special technology can elevate blood BHB levels to the optimal range of 1.5–2.5 mmol/L for a longer period of time, helping athletes reap the performance benefits of elevated ketones without negatively impacting blood pH.
Ketone Esters and Athletic Performance
You may have seen an Australian study that examined the performance effects of ketone esters, another type of exogenous ketone, 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 from the results using Ketone 2.0?
- The ketone ester used was an Acetoacetate Diester (AcAc2 ester). This is a very different compound to the pure R-1,3-butanediol (R-1,3-BDO) found in Ketone 2.0.
- The AcAc2 ester contains 3 "ketone equivalents": 2x AcAc and 1x racemic butanediol. The Ketone-IQ technology found in Ketone 2.0 contains a chirally pure form of R-1,3-BDO. Because of differences between these exogenous ketones, the blood BHB levels were much lower after the AcAc ester: ~1.1 mmol/L. In comparison, Ketone-IQ raises blood BHB to an optimal range of 1.5–2.5 mmol/L. This difference 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 much refinement. In the Australian study, the AcAc2 ester caused every participant GI distress. This is likely to have a HUGE impact on performance—athletes are never going to do well if they feel sick! Ketone 2.0 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 (versus 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 on athletes (total n = 22). Performance over a 4-minute cycling time trial and a 150 kJ (~10 minutes) cycling time trial were compared between ketone salts (without carbohydrates) versus carbohydrates alone. In the 4-minute trial, athletes experienced no change in performance. In the 150 kJ test, performance decreased by 7%. Blood BHB levels peaked at 0.6–0.8 mmol/L in these studies.
Learn more about this topic here: How do exogenous ketones affect athletic performance?