Norwegian biathlete Bakken was wearing a hypoxic mask when he died in Trentino

The Norwegian Biathlon Federation confirmed that Sivert Guttorm Bakken, 27, was found dead on Monday in a room at the Albergo Dolomiti at Passo di Lavazè, Trentino, Italy. At the time of his death, he was wearing a hypoxic training mask designed to simulate altitude by restricting airflow and thereby reducing the amount of oxygen reaching the lungs.

In its statement, the federation said that “the circumstances related to the acquisition and use of this mask are currently unknown.” An autopsy will be carried out in Italy in the coming days. Bakken’s family is in contact with local police, and investigators from the police and forensic units will work to establish the sequence of events and the cause of death. The federation added that it will inform the media as soon as further information is available.

Bakken suspended his competitive career in 2023 due to pericarditis, but after nearly two years away he had recently returned to the World Cup with Norway, the leading men’s biathlon nation. The device cited in the case—often referred to as an Elevation Training Mask (ETM)—has gained popularity among athletes for purported benefits such as improved respiratory capacity, increased lung capacity, and enhanced hypoxic tolerance. Manufacturers claim it can reduce airflow by six to ten times, effectively creating an adjustable, controlled form of oxygen deprivation. However, the use of such masks remains controversial and, as this incident underscores, they may carry risks for the wearer.

Italian media also noted that prosecutors in Trento have indicated there are currently no suspects while they await the autopsy. Authorities have reportedly seized the mask as part of the investigation.