Training with an extra supply of oxygen, so-called hyperoxia, has been banned for those active in SOK's Top and Talent Program since 2016. But there are athletes who use it, including marathon star David Nilsson (who is not part of SOK: s program).

The Swedish Olympic Committee believes that the method, among other things, "contradicts the idea of ​​sport and the Olympic values" and "sends the wrong signals to sports children and young people".

In Assignment review and SVT Sports 'series "Sports' borderland", SOK's operations manager Peter Reinebo also refers to the fact that the international anti-doping agency Wada has called on unions to introduce their own rules against hyperoxia - even though the method is not on Wada's list of doping-classified drugs and methods .

"A sharp recommendation"

- Wada has decided not to put it on his list.

On the other hand, there is a sharp recommendation to international federations that it should be banned and the IOC has taken it into account, and during the Olympics, that type of oxygen supply in an artificial way, for example with tubes and masks, is prohibited, says Peter Reinebo.

The International Olympic Committee therefore has a ban on hyperoxia during the Olympics.

But the method is not on Wada's doping list.

- Regardless of type, Wada wants you to have it in the competition rules.

That oxygen, regardless of what pressure you keep in your lungs, must be regulated in the competition regulations, says Bo Berglund, medical officer at SOK.

SOK is stuck

Wada's press officer James Fitzgerald believes, however, that no call has been made to the unions to ban it in their own rules.

"As stated in section M1.2 of the list of banned substances and preparations, it is not forbidden to inhale extra oxygen, and Wada has not asked the sports federation to ban the use of it," he writes in an email to SVT.

When SVT confronts SOK's medical officer with the information, he stands by SOK's decision.

- Our position is not changed by the fact that Wada has decided to act in one way or another, but our point of view is clear.

It is not something to engage in, regardless of which form or arena prohibits this, says Bo Berglund.

SVT has contacted Peter Reinebo for a comment on Wada's message.

Three things from the review "Sports' borderland":