Merijn Zeeman, Jumbo-Visma's sporting director, claimed that rival teams are "looking for excuses" to slander his team and complain about its use of ketones in the professional peloton.

In a lengthy interview with L'Équipe (open in new tab), Zeeman suggested that the Movement for Reliable Cycling (MPCC) opposes the use of ketones to maintain its relevance.

He also dismissed athletes' concerns that a "two-speed cycling" may be developing between teams that adhere to MPCC rules and those that do not.

"Allegations often come from the French. The French may not like this, but I don't think they work with the same professionalism as we do," Zeman told L'Équipe.

"They regularly point out that our results are due to ketones or mechanical doping. Not only France, but some teams refuse to face up to their own lack of standards and say that other teams are doing dodgy things.

Jumbo Visma, the current UCI ranking leader, is one of the WorldTour teams that have confirmed their use of ketones; MPCC member teams have committed to additional voluntary rules prohibiting ketone use.

Zeman described the debate over ketones as "more ridiculous than ever in cycling" and said that ketone use accounts for a small part of the team's success.

"It's not even 1% of our work on performance," Zeman said. 'Ketones are almost nothing. But as long as ketones are allowed, we have the right to test if ketones will help our riders."

WADA told Cycling News last winter that ketones do not meet the criteria to be banned. Meanwhile, UCI Medical Director Xavier Bigard said, "There is no scientific evidence that ketones improve performance. However, the UCI is conducting further research.

Zeman claimed that the MPCC has opposed ketones because they "needed to find something to maintain their voice in cycling."

"It's good to discuss everything in a high-level sport, but isn't the goal of the MPCC to attack what is really bad or in the gray area? [It is annoying to hear so many athletes, especially the French, talk about two-speed peloton when they talk about ketones. Bardet, Pino, and Demare talk about it, but it is nonsense."

The most important of the MPCC's voluntary rules, however, is about the use of corticosteroids. Until this year, when WADA banned the injection and oral administration of corticosteroids, the MPCC voluntarily conducted cortisol testing for its members.

Jumbo-Visma, then known as LottoNL-Jumbo, left the MPCC in 2015 after George Bennett was excluded from the Giro d'Italia lineup due to low cortisol levels.

"We don't use corticosteroids," Zeman says. 'It's bad for your health. And it is not allowed. That's totally different."

Jumbo Visma has enjoyed remarkable success in recent seasons, including a third consecutive Vuelta a España victory by Primoš Roglič, but failed to win the 2020 Tour de France, despite dominating most of the three weeks of racing.

Roglič lost the yellow jersey to Tadej Pogačar on the final day at La Planche des Belles Filles. In a documentary about the Tour, Roglič and Tom Dumoulin questioned the legitimacy of Pogačar's victory.

"I did not interpret their comments that way," Zeman said. 'I think the riders were stunned by Pogachal's extraordinary performance that day.'