Cycling’s international governing body has announced a new ban on the repeated use of carbon monoxide rebreathing in the sport. This decision follows growing concerns over the health risks associated with the practice, which some athletes have allegedly misused to enhance their performance. The prohibition will be officially implemented starting February 10.
The technique involves inhaling carbon monoxide (CO), which can be utilized to monitor the diffusion of oxygen in the lungs or measure the total mass of hemoglobin—a critical blood value for endurance athletes. During major cycling events, such as the Tour de France, reports emerged suggesting that riders from several teams had been inhaling the gas to optimize their altitude training. The practice caught significant attention when a prominent rider remarked that regularly inhaling low doses of carbon monoxide could lead to a notable boost in performance.
Despite these claims of performance enhancement, the cycling authority’s decision to ban the practice is rooted in medical concerns. Repeated inhalation of carbon monoxide, especially outside controlled medical environments, poses substantial health risks. Acute exposure can lead to headaches, nausea, dizziness, and confusion. In more severe cases, chronic exposure may escalate to heart rhythm abnormalities, seizures, paralysis, and even loss of consciousness.
In response to these dangers, the new regulations will specifically prohibit the possession of commercially available carbon monoxide rebreathing systems outside of medical facilities. These systems are typically connected to both oxygen and CO cylinders, facilitating the controlled inhalation of the gas. Under the updated rules, the only permissible use of carbon monoxide inhalation will be within a medical facility and under the guidance of a qualified medical professional experienced with the gas. Even then, its use will be strictly limited. Only one inhalation will be authorized to measure the total mass of hemoglobin, and any subsequent measurement can only occur two weeks later.
Interestingly, the World Anti-Doping Agency (WADA) still permits the method, which adds a layer of complexity to the ban. The cycling authority has requested WADA to review its stance on the issue, potentially paving the way for a broader prohibition across other sports as well. The debate over the ethical and health implications of using substances or methods like carbon monoxide rebreathing reflects the ongoing tension between performance enhancement and athlete welfare in elite sports.
While altitude training itself remains a legal and widely accepted method for improving endurance, the use of carbon monoxide rebreathing appears to blur the line between natural training adaptations and artificial enhancements. The governing body’s decisive action serves as a reminder of its commitment to athlete health and the integrity of competition. It highlights the need for vigilance as sports science and training methodologies continue to evolve, sometimes at a faster pace than the regulations designed to oversee them.
This ban also serves as a precautionary measure, underscoring the unpredictable nature of how emerging performance strategies might impact athlete health long-term. For the cycling community, it is a moment to reflect on the lengths to which competitors go in pursuit of victory and the responsibilities of the governing bodies to maintain a safe and fair playing field.
Looking forward, the dialogue between sporting authorities, medical professionals, and athletes will be crucial in navigating these complex issues. The goal is to strike a balance where innovation in training and recovery can coexist with the safeguarding of athlete health and the principles of fair competition. With the ban in place, attention now shifts to enforcement and whether other sports might follow suit, as the interplay between science, ethics, and regulation in sport continues to unfold.
