PARIS — Two-time Tour de France champion Jonas Vingegaard is calling for a ban of the controversial carbon monoxide rebreathing method used by athletes to measure their performances.
Speaking to Le Monde newspaper, the Visma-Lease a Bike rider said in an interview published Saturday that his team makes a proper use of the method, but that some riders misuse it to artificially increase their performances.
The use of carbon monoxide was put under the spotlight during the Tour de France last year when the cycling website Escape Collective reported that riders from multiple teams inhaled the toxic gas to optimize altitude training.
The gas can be used as a tracer to monitor the diffusion of oxygen in the lungs or the total mass of hemoglobin, a key blood value for racers.
“My team uses carbon monoxide to measure blood volume and total hemoglobin mass,” he said. “We inhale the monoxide a first time, before a training course at altitude. At the end of the course, the operation is repeated to calculate your maximum oxygen absorption capacity.”
But Vingegaard added that some are using the method to dope “by regularly inhaling low doses of carbon monoxide, which leads to a significant increase in the performance.”
“This is not right and should be banned by the World Anti-Doping Agency,” he said.
Cycling governing body the UCI said in December that a ban for medical reasons will be discussed by its management committee at a meeting in France from Jan. 31-Feb. 1.
The UCI said that the gas, when inhaled repeatedly in non-medical conditions, can have side effects such as “headaches, fatigue, nausea, vomiting, chest pain, breathing difficulties, and even loss of consciousness.”
During the interview, Vingegaard was asked about the performances of his rival Tadej Pogacar — who won the Giro, the Tour de France and the road world championships in 2024 — completing the “triple crown” of cycling — as well as other prestigious one-day races.
“I understand the doubts surrounding his performances, but he has set new standards that we now need to reach,” he said. “He is the best rider in the world. That being said, the gap between us is not that big. I could have challenged him on the Tour.”
Vingegaard was runner-up at the Tour last year, lagging more than six minutes behind Pogacar. But his preparations for cycling’s biggest race had been seriously hampered by a crash in which he sustained a broken collarbone and ribs and a collapsed lung.
“I probably would have done better in the Tour had it not been for the shortened preparation after my accident, which had a big physical and psychological impact,” he said. “To win the Grande Boucle, every detail counts and I’m still happy with second place.”
