Carbon Monoxide rebreathing is a topic that has seen daylight this past June when an investigation showed that a few top teams, including UAE Team Emirates and
Team Visma | Lease a Bike, had experimented with what may be a method to improve performance. Whilst not banned it's highly controversial, but it's use is also a mystery.
Jonas Vingegaard has weighed in on it.
The Dane had already answered questions regarding it at the Tour de France, and explained what had been said previously which is that the team uses it for testing during altitude camps.
"I didn't even know it could be misused," Vingegaard said in an interview with
NOS. "I said before that we only used them to test whether altitude training works. If you misuse it, it can be a substitute for altitude training. If you use it that way, there may be health risks involved. But we use it differently."