Will cycling ban carbon monoxide rebreathing?

The International Cycling Union (UCI) is expected to vote this week to ban the use of carbon monoxide rebreathing devices. This follows evidence last year that some teams were using the devices to measure hemoglobin levels in blood before and after athletes underwent altitude training. While not explicitly prohibited by existing rules, questions have arisen as to whether repeated use of the device could enhance athletic performance, or if simply inhaling a deadly gas for scientific measurement is too dangerous.

Currently, it appears highly likely that the technology will be banned. However, the specific implications of this ban have caused growing confusion within the cycling world, as the UCI is expected to allow the use of the device in "medical settings." According to BBC Sport, if the ban is approved, it will likely take effect immediately.

Carbon monoxide rebreathing is a long-standing technique in endurance sports. It involves athletes inhaling small amounts of carbon monoxide, a deadly gas produced when anything burns, because it can measure the amount of hemoglobin in the blood. This is typically done at the start and end of altitude training. Hemoglobin is a protein in red blood cells responsible for transporting oxygen throughout the body. The more hemoglobin in the blood, the more oxygen muscles can receive, improving an athlete's ability to resist lactic acid buildup, helping them to perform faster and for longer.

The device is connected to an external oxygen and carbon monoxide supply, with athletes using an integrated rebreathing circuit. Cycling has long struggled with negative associations related to blood issues, stemming from Lance Armstrong's infamous blood doping, where he increased his red blood cell count through transfusions to cheat his way to Tour de France victories around 20 years ago. The current carbon monoxide rebreathing issue might not be so prevalent if some of the top teams and riders weren't involved. This includes three-time Tour de France champion Tadej Pogačar and his UAE Team Emirates, as well as his strongest rival, Jonas Vingegaard from Team Visma-Lease a Bike.

Rumors about the use of the technology began to surface during last year's Tour de France, coinciding with a significant increase in winning margins for some of the top riders. The device's manufacturer has admitted that performance enhancement is possible, although easily detectable. Karsten Lundby, co-founder of device manufacturer Detalo Health, stated, "When you inhale carbon monoxide, the oxygen level in the blood decreases, so the body behaves as if you were at high altitude. If you only inhale once, it's like being at high altitude for a few hours, which has no effect on your performance. If you inhale carbon monoxide four or five times a day for a month, your hemoglobin level will increase, but that's an abuse of our device, which is not its intended purpose." Lundby also said they can monitor each machine in real time, making it easy to identify if a device is being misused.

The UCI is not implementing the ban solely to combat cheating. They stated that the ban is for safety reasons, and that the technology can still be used in "medical settings." However, Lundby and the teams are confused by this. Lundby stated, "Initially I was happy to see the UCI take a stand, but then I was confused by the wording about allowing these procedures in medical settings. I don't know of any medical settings that would do this. My colleagues and I have contacted the UCI to point out that 99% of measurements are not done in medical settings, but by medically trained personnel. I believe the wording will change."

Israel-Premier Tech team purchased the device and hired Lundby himself to use it. The team stated, "The sole purpose of the Israel-Premier Tech team using the device was to test the effects of altitude training." Team Visma-Lease a Bike said that this "is not new, this method has been used for decades to measure the effects of altitude training." They added, "It is completely normal practice in multiple sports, done by experienced scientists and with their equipment. In this context, it is neither harmful to health nor does it enhance performance."

So, if it can indeed enhance performance, can it be tracked? In theory, any changes in blood values would be identified through an athlete's biological passport. However, the World Anti-Doping Agency (WADA) is not taking any chances and is investigating. A WADA representative stated, "The issue of exposure to carbon monoxide has been discussed multiple times by WADA. There is currently no consensus on whether carbon monoxide enhances performance, and there is not enough reliable data to support this claim. However, WADA is currently investigating the impact of frequent and repeated use of carbon monoxide rebreathing methods on artificially increasing oxygen uptake, transport, or delivery. Regardless, it is generally believed that it may be harmful to health, and therefore its use is not recommended."

Many believe that this issue has been hyped up by the cycling media, and that the UCI is simply taking a proactive approach to make a statement. The UCI is expected to announce any decision on February 1st, after President David Lappartient formally presented the request to the executive body at a meeting in France. It remains uncertain when WADA will know if further action is needed, but the teams have stated that they are prepared to cooperate with the UCI on any decision. Until then, this technology has once again raised questions in cycling, a sport that could have done without them.