What are ketones and why are the Tour de France’s top teams using them?

Ketones are gaining popularity amoung endurance athletes. Recent studies show they can substantial improve recovery and can even give a boost of performance of up to 15 per cent. So it should come as no surprise that WorldTour cycling teams are using them to boost the performance of their riders. According to reports, as many as six teams currently racing the Tour de France could be using ketones.

“Ketones are a dietary supplement. You can use this just like vitamins. The substance is not on the prohibited list. It is also known that other teams use ketones, ” Jumbo-Visma team manager Richard Plugge told De Telegraaf revealing that the Dutch team gives them to their rides.

Jumbo-Visma has four stage wins at the 2019 Tour de France. Mike Teunissen won the opening stage in Belgium in a sprint. The team scorched the team time trial course on Stage 2 putting 21-seconds into the usually dominant Team Ineos. The team’s lead sprinter, Dylan Groenewegen found success on Stage 7. The first phase of the Tour ended with three-time cyclocross world champion Wout van Aert winning in the sprint on a crosswind affected Stage 10. With three sprint wins from three different riders and a dominant display in the TTT, Jumbo-Visma are on fire.

Last year, The Telegraph reported that Team Sky, Mitchelton-Scott, Groupama-FDJ, Dimension Data and Sunweb all denied using ketones on their athletes while the BMC racing team, which merged into CCC at the end of the year, declined to comment. According to reports, many members of the British team were using ketones during the 2012 London Olympics after biochemist Kieran Clarke of the University of Oxford helped to develop the first ketone ester drink.

What are ketones?

A ketone body is a substance produced from fatty acid when our body is in a state of ketogenesis. This state is known as a state of survival that allows our body to survive a period without carbohydrate intake. A person who follows a strict ketogenic diet will start producing ketone bodies to give energy to normal daily functions and training.

It is now possible to supplement your diet with ketone bodies in liquid or powder form. Powdered ketone bodies (ketone salts) are either BHB (beta-hydroxybutyrate) linked to an amino acid or to a mineral salt (sodium, potassium or calcium). This allows the ketone body to exist in powder form and easily dissolve in water. The same way that one consumes protein powder or electrolytes.

Liquid ketone body supplements (ketone esters) contain only ketone bodies. They are attached by an ester linkage to a precursor of a ketone body such as butanediol or glycerol. Studies on fluid supplements are much more conclusive than studies with powdered supplements. These supplements are, however, much more expensive. For example, three small bottles of 25 grams of HVMN brand ketones sell for US$99 while KetoneAid sells bottles with 300 grams of ketone ester for US$320.

Do ketone bodies work?

A recent study published by Peter Hespel, a Belgian sports science researcher who works with the WorldTour Quickstep cycling team, has demonstrated the effect that liquid ketone bodies can have on recovery. The subjects conducted an intense training camp of three weeks to simulate the load and duration of a competition like the Tour de France. Nine subjects consumed the ketone body supplement and nine others took a placebo. Participants drank up to three bottles a day, one after each workout and one before going to bed.

Carbohydrates and fats provide us with energy to allow us to train at different intensities, and proteins are essential to repair muscle breakdowns and allow us to recover. However, there is another energy source that could be beneficial for energy and muscle recovery: ketone bodies.

“The evidence for using Ketone ester – which is this drink they’ve created – seems to be that it reduces the emphasis on carbohydrate metabolism,” explained Team Sky’s nutritionist James Morton in 2018. ” On the one hand, this could be a good thing as it may spare muscle glycogen use meaning you have more for later. On the other, if it surpasses the ability of muscle to use carbohydrate as a fuel then this could really be detrimental to performance. So, whether it’s a good thing or a bad thing  is too early to say.”

Does it work?

A recent study published by Peter Hespel, a Belgian sports science researcher who works with the WorldTour Deceunick-Quick Step cycling team, has demonstrated the effect that liquid ketone bodies can have on recovery. The subjects conducted an intense training camp of three weeks to simulate the load and duration of a competition like the Tour de France. Nine subjects consumed the ketone body supplement and nine others took a placebo. Participants drank up to three bottles a day, one after each workout and one before going to bed.

By the third week of the camp, the group that consumed the ketones was able to perform sustain training load 15 per cent higher than the placebo group. As well as push a power output 15 per cent higher in a time trial effort.

At the end of these three weeks, all participants had a reduction in their max heart rate during maximal and submaximal exercise, which is normal following a long period of intense training. However, the reduction in heart rate was lower in subjects who consumed the ketone supplement, which may demonstrate the effect of this supplement on recovery.

“I have heard a cyclist say that he had participated in a dozen Tours of France, one of which on ketones. With that one on ketones, his heartbeat in Paris had hardly dropped compared to his heartbeat with the prologue,” said Hespel who has ketones effects on recovery unprecedented.

Ketones are not-currently banned by WADA but some teams appear to still be cautious about employing them on their riders during a rigorous three week Grand Tour.

“There is much uncertainty about the efficacy. There are even studies that show that it has a negative effect on sports performance. That the remedy would only be good for recovery. We want to be sure that we will not harm our riders,” said Team Sunweb doctor Anko Boelens.