Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "
You need to know this before you buy ketones
The two most important ketones are beta-hydroxy butyric acid (BHB) and acetoacetate.
There are small studies in which, for example, elite soldiers perform better due to a diet with particularly low carbohydrates, but in a number of larger studies there is often little left of those interesting effects. [J Spec Oper Med. Summer 2017;17(2):112-6.] But we're not going to talk about low-carb diets.
Effects of ketones
So it is not so strange that in the first half of the 1980s nutritional scientists came up with the idea of giving ketones as a supplement to athletes. Those athletes don't fast and continue to eat carbohydrates, but thanks to the ketone supplements can still benefit from the positive effects of a low-carb diet or a diet of fasting.
At least, that's the idea.
However, studies do not show that athletes benefit from ketone salts. They do not dispel fatigue, [Appl Physiol Nutr Metab. 2017 Oct;42(10):1031-5.] cause nausea, diarrhea and other abdominal complaints, [J Nutr Metab. 2018 Apr 12;2018:9812806.] and may even degrade performance with high-intensity exercise.
These side effects may be due to the hefty amount of minerals that athletes ingest when they use ketone salts. It is so high that long-term use of ketone salts without intensive medical supervision is dangerous.
Another possible reason for the disappointing results of ketone salts supplementation is that ketone salts do not contain one type of BHB, but a mixture of two types of BHB molecules: D-BHB and L-BHB. Chemists call such a mixture 'racemic'.
Physiologists suspect that racemic mixtures of BHB do not have a performance-enhancing effect. In the human body you mainly find D-BHB, and only a few L-BHB. The body converts D-BHB into energy, but not L-BHB. Supplementation with D-BHB has positive effects, supplementation with L-BHB has no effect or even a negative effect.
The media reports on the use of ketones in elite sport relate to this specific ketone supplement.
D-BHB mono-ester in the body only converts to D-BHB. Endurance athletes who receive 30-35 grams of D-BHB mono-ester burn more fat and fewer glucose, according to studies. [[Cell Metab. 2016 Aug 9;24(2):256-68.] Their muscles also are able to absorb more glucose from their blood. [Med Sci Sports Exerc. 2017 Sep; 49(9):1789-95.]
Not surprisingly, ketone supplementation increases endurance capacity by a few percent. This sounds modest, but in cycling, the effect of these few percent is immense.
There is hardly any research into the use of D-BHB mono-ester in strength sports, but it seems that ketones can accelerate recovery after strength training. [Front Physiol. 2017 May 23;8:310.]
If as many athletes use ketones as the sports media suggest, those companies will make a profit. An average athlete who uses D-BHB mono-ester needs just over 50 euros a day.