The UCI has asked the World Anti-Doping Agency (WADA) to take a position on the use of carbon monoxide (CO) by professional cycling teams after it came to light during the Tour de France that some sides were using it to optimise altitude training.
At the governing body's annual Seminar in Nice, France, the UCI also warned teams about the dangers of carbon monoxide inhalation and requested riders and teams not to use "repeated inhalation" of the deadly gas.
Escape Collective first unveiled CO's use in the professional peloton and confirmed that teams such as Visma-Lease a Bike, UAE Team Emirates and Israel-Premier Tech had used carbon monoxide rebreathers to measure blood values and maximise their gains from altitude camps.
Headline stars Tadej Pogačar and Jonas Vingegaard also confirmed they were aware of and had at least partially used the rebreathing equipment, a practice not banned by WADA, with its use quickly becoming a contentious issue.
Inhalation is a different method completely from rebreathing, with the former potentially leading to an increase in aerobic capacity like VO2 max and the latter being a measurement tool that can aid in maximising the physiological benefits of altitude training.
Escape Collective's initial findings confirmed that there was "no hard evidence that any WorldTeams are currently using CO inhalation for performance gains" at the time of publication in July - it's the potential for it which is worrying the UCI.
"Seminar participants were brought up to date on the current knowledge of the effects on performance of repeated carbon monoxide (CO) inhalation," read a UCI press release.
"The UCI clearly asks teams and riders not to use repeated CO inhalation. Only the medical use of a single inhalation of CO in a controlled medical environment could be acceptable.
"The UCI is also officially requesting the World Anti-Doping Agency (WADA) to take a position on the use of this method by athletes."
Pogačar described the confirmed rebreather use as "a pretty simple test to see how you respond to altitude training" when speaking at the Tour, while Vingegaard concurred that "there is nothing suspicious about it" speaking to Danish newspaper Politiken.
Another key group, the Movement for Credible Cycling (MPCC), recently called for the technique not to be practised, prompting a response from Detalo Health, the company behind the rebreathers used by several WorldTour teams.
“With the health risk (potentially fatal), the complex and artificial technical aspect (misuse of technical and therapeutic means to artificially create physiological changes), and the world anti-doping code in force, the MPCC can only and strongly advise against the use of this technique… until it’s banned," read an MPCC press release.
"I completely agree that we should advise against the use of carbon monoxide inhalation with the intent to increase haemoglobin mass. That should be clear. And we have stated this on numerous occasions already," said Carsten Lundby, CEO of Detalo Health, to Cyclingnews in response.
"The use of carbon monoxide as a medical diagnostic tool is, of course, an entirely different thing where the intent is not to increase performance, but as a diagnostic tool. And that should, of course, not be forbidden, or cannot be forbidden. So there needs to be a clear distinct treatment between the two.
"I'm very much against carbon monoxide inhalation with the intent to increase performance. I think it's against the spirit of sports. I don't want my kids to inhale toxic gas in order to become World Champions."
Speaking earlier in November, Lundby also confirmed that Detalo plans to continue working with WorldTour teams in 2025.
