Cycling’s governing body bans carbon monoxide rebreathing on health grounds

Cycling’s governing body has banned the repeated use of carbon monoxide rebreathing that some riders allegedly misuse to artificially increase their performances.

Following a meeting of its executive committee on Saturday in France, the UCI said it approved a ban on repeated inhalation to protect the health of riders. The ban starts on 10 February.

The inhalation will, however, continue to be authorised “within a medical facility and under the responsibility of a medical professional experienced in the handling of this gas for medical reasons”, the UCI said.

The use of carbon monoxide (CO) was put in the spotlight during the Tour de France when the cycling website Escape Collective reported that riders from multiple teams inhaled the toxic gas to optimise altitude training.

CO gas can be used as a tracer to monitor the diffusion of oxygen in the lungs or the total mass of haemoglobin, a key blood value for racers. Two-time Tour de France champion Jonas Vingegaard said last month that some are using the method “by regularly inhaling low doses of carbon monoxide, which leads to a significant increase in the performance”.

The UCI decided to act on medical grounds, saying that the gas, when inhaled repeatedly in non-medical conditions, “can result in acute and chronic health problems, for example headaches, lethargy, nausea, dizziness, and confusion”.

It added: “Such symptoms can worsen at any time and develop into problems with heart rhythm, seizures, paralysis, and loss of consciousness.”

The new rules prohibit the possession, outside of a medical facility, of commercially available carbon monoxide rebreathing systems connected to oxygen and CO cylinders, the UCI said.

When performed under medical supervision, the UCI said only one inhalation will be authorised to measure the total mass of haemoglobin, with a second inhalation allowed only two weeks after the first measurement.

The method remains authorised by the World Anti-Doping Agency and the UCI said it has requested the body to take a position on the issue.