Cycling is so full of baffling jargon that it almost threatens to spoil the fun at times. If it’s not the complexity of power measurement, then it’s the physiology of fueling or the PhD-level physics behind aerodynamics that tricks the wind. The latest buzzword that has us grappling with its meaning is ketones, described by some as a groundbreaking legal performance-enhancing supplement. More and more WorldTour teams are announcing collaborations with providers of the mysterious drinks, which are difficult to ignore. But what exactly are ketones and do they really live up to all the hype?
This much is clear: ketones are ubiquitous among pros, as I experienced firsthand during Paris-Nice in March. On several stages, as riders crossed the finish line, they grabbed jackets, Haribo and, in some cases, ketones from waiting soigneurs before returning to their team buses.
Soudal Quick-Step was one of many teams to use the drinks and was active on social media during the race, sharing videos of Remco Evenepoel guzzling sponsor KetoneAid’s products after the stage. Witnessing this new phenomenon, a multitude of thoughts entered my mind. Do the riders who use these products really believe in their effectiveness and, on the other hand, do those who don’t use them dismiss them as worthless?
A quick search online revealed that DeltaG, the ketones used by Mathieu van der Poel’s Alpecin-Deceuninck team, were developed at the University of Oxford, near where I live. A few emails later I was on my way to meet the scientists behind the drinks. I wanted to break down the wall of secrecy surrounding ketones to find out what it’s really all about.
Visma-Lease a Bike was the early adopter of the supplement
(Image credit: Getty Images)
Alternative fuel source
First, what are ketones? In short, they are a fuel produced naturally in the liver when the body breaks down fats, making them an alternative fuel source when glucose availability is limited, such as during long rides. “There is no human body where ketones are not present,” says Professor Kieran Clarke of the University of Oxford, ketone researcher and the brains behind DeltaG, one of the many ketone brands used in cycling today. “Fat is broken down into ketones,” she explains, “which are very similar to glucose [molecules] and work in a similar manner.”
The ketones used in supplements are ketone esters, a synthetic compound consisting of a ketone group bonded to an ester group. By taking these exogenous ketones in drink form, athletes theoretically provide themselves with an additional fuel source in addition to their glucose reserves to ensure they can go the distance during long, tough events. However, the Movement for Credible Cycling (MPCC) group, which includes Groupama-FDJ, Confidis and Bora-Hansgrohe, bans its member teams from using exogenous ketones. Why this skepticism, given that ketones are produced naturally? “The UCI says it is investigating the long-term health effects of ketone use,” says MPCC president Roger Legeay Cycling every week. “We want to await the results of the investigation.”
Hold your nose: taste test
In a clip on social media after the recent Flèche Wallonne, Soudal Quick-Step’s Ilan van Wilder was photographed holding his nose as he drank a bottle of KetoneAid at the finish. After recently trying ketones myself, I understood why: the taste is awful.
When I tried ketones to check their effect on my own performance, I was immediately put off by what can only be described as a bitter, metallic taste. The DeltaG product I tried was listed as blueberry flavor, but it was enough to put you off blueberries for life.
Javier Gonzalez believes the bad taste is part of what has raised questions around the legitimacy of ketones. “The bad taste adds to the mystique surrounding ketones. People think, ‘Oh, this tastes terrible, it must be doing something really powerful,’ so I think it’s probably partly that.”
The MPCC’s stance is hardly surprising, especially since the initial involvement of ketones in cycling sparked such a high-profile controversy. This was at the time of the 2012 Olympic Games in London, when it was not yet known whether the drug could violate anti-doping laws. A report in the Mail on Sunday in 2020 revealed that DeltaG was being secretly tested by some of Britain’s top riders in the lead-up to the races in a testing program endorsed by UK Sport. According to Sporting Intelligence, the product was not medically approved at the time and yet 91 guinea pig athletes from various sports signed non-disclosure agreements stating that if they became ill from using the product they would not discuss what they had done. with people outside the program. The Mail on Sunday report stated that, if discovered, the plan was to portray the scheme as GB simply leading the way in marginal profits development.
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Research on ketones has advanced significantly since then and they are not currently banned by the UCI, the World Anti Doping Agency (WADA) or the International Olympic Committee. [IOC]. Clarke tells me that exogenous ketones were initially produced at the University of Oxford at the request of the US Department of Defense. The U.S. military’s hope was that ketones would give troops an extra edge and help them stay fueled longer when operating on low rations behind enemy lines and during combat.
Visma’s vision
In cycling, ketones are no longer primarily seen as a fuel product, but rather as a recovery aid, as Martijn Redegeld, head of nutrition at Jonas Vingegaard’s Visma-Lease a Bike team, explains. “I think the whole buzz around ketones started five or six years ago,” he says.
“There were two different reasons for using them, one was more focused on the acute performance benefits, which meant riders had to take ketones shortly before or during a race; the other area was more focused on recovery purposes and training adaptive responses. I think research in recent years has shown the most promising effects in that secondary area, on the recovery side.”
Ketone is reported to improve your sleep
(Image credit: Getty Images)
Cycling every week contacted other WorldTour teams to discuss the use of ketones but received no response. Some teams acknowledged their use of ketones but declined to discuss why. Professor Clarke says research shows ketones have the power to improve cognitive performance while providing a physical boost. However, Visma’s Redegeld is not yet certain about the cognitive benefits. “That’s an area that the research is focusing on, but to be honest I think that part is still quite unexplored,” he says. “The evidence so far is anecdotal. What is clear is that ketones are more than just a fuel. At first they were thought to be like carbohydrates, just extra fuel, but now we know that they can be seen as a signaling molecule that triggers all kinds of other processes in the body.”
Ketones for the night: sleep booster
(Image credit: Getty Images)
If you can overcome the feeling of nausea upon consumption, ketones are reported to improve your sleep and quickly have you napping like a pro. Professor Gonzalez explains why: “They appear to potentially have some effect on the balance of hormones, including noradrenaline,” he explains, “which could have a direct effect on sleep, but ketones can also affect sleep indirectly because they also reduce urine production. So if you have a ketone ester you don’t have to go to the toilet as often, which can mean you don’t wake up at night because you have to go to the toilet.’
Researchers at universities around the world continue to investigate the benefits and side effects of ketones. One stumbling block is cost: exogenous ketones are so expensive that it can be difficult to complete research projects. “Some of the ketone studies we’re interested in are long-term, where people do them for weeks at a time, but then the costs skyrocket and are difficult to finance,” says Javier Gonzalez, professor of human metabolism at Bath University . “This is why we currently have no projects in the field of ketones.”
It is also for cost reasons that Gonzalez believes that amateurs are better off spending their money on other forms of performance enhancement. “I do think about the cost-benefit ratio [from ketones] is small,” he says. “Even if they do improve performance, there are probably other cheaper things that will give you more bang for your buck, at least based on what we currently know.”
For example, the DeltaG ketone drink is available in boxes of three, with the most expensive retail price being £75 per box.
Believers and skeptics
Redegeld echoes Gonzalez’s views on costs, saying that while amateurs may see benefits in using the product, he would recommend making changes elsewhere first. “My advice is always that amateurs should start by getting the basics right,” says the Visma nutritionist. “Just meeting your energy needs, getting good calories and the right amount of carbohydrates will provide a much greater benefit. But I think for an ambitious amateur who does all these things correctly, ketones can certainly be an extra.”
Like Visma-Lease a Bike, UAE Emirates – the team of two-time Tour champion Tadej Pogačar – is not part of the MPCC and could therefore use ketones freely. So it’s interesting that UAE riders are advised against using them. Outspoken sports scientist Iñigo San Millán, the Pogačar team’s head of performance, is not convinced. “We know that the best fuel for contracting muscles during high-performance exercise is glucose and also lactate,” he tells CW. “Ketones are available as additional fuel. Yes, that extra fuel works, but it is a poorer, lower quality fuel compared to carbohydrates. This is why when an athlete asks me if he should eat carbs or ketones, it’s always carbs. We always try to educate them and explain why having ketones during competitions can be harmful.”
Ketones are not banned in the UAE, but San Millán explains to riders that there are better alternatives. What about the alleged recovery benefits? “For a recovery drink or formulation, I always stick to carbohydrates and proteins, rather than ketones. In my opinion, ketones are a low-quality fuel,” says San Millán.
Unlike university researchers, it is not budgetary constraints that prevent UAE Emirates from using ketones. “Sometimes athletes have asked us, ‘Is the team going to deliver these ketones?’ The answer is no, and the reason is because we don’t believe they are necessary,” he explains. “In my humble opinion, there are better ways to manage your diet effectively.”
With highly qualified scientists like San Millán writing up the effectiveness of ketones, it’s hard to understand how much faith some teams place in them – especially since they’re unwilling to discuss their reasons. Cycling’s dark past means that any supposedly new performance-enhancing drug will arouse suspicion. However, amateur riders would have to be very convinced of the benefits of ketones to regularly spend £75 on a drink that, at best, produces a marginal gain.