Victor Kampenaerts (NTT Pro Cycling) has already made headlines for comparing sleeping in a high altitude tent to EPO, but the Belgian, who slept at 4,700 meters altitude, took oxygen deprivation to a new level before the season resumes in August.

Kampenaerts told Het Laatste Nieuws that he simulates being at 10,000 meters for an hour each day. For comparison, the summit of Everest is 8,848 meters, and altitudes above 8,000 meters are known as the "death zone" among climbers.

"Masking for an hour every afternoon reduces your oxygen supply," Kampenatz says. This concept is called "intermittent hypoxic training" and has been scientifically studied.

"Extremely low oxygen levels give the body an extreme incentive to produce extra red blood cells. I don't think many athletes do this. I am trying to be a pioneer and now I have time to try it."

The effective oxygen concentration at 10,000 meters altitude is less than 6 percent, half of what Kampenaerts experiences at 4,700 meters altitude and 15 percent below sea level.

Campenaerts could only run eight hours a week when sleeping at 4,700 meters altitude. At twice the elevation, on the other hand, even simple tasks become nearly impossible.

"The oxygen supply is reduced. 'I just lay on the bed and can't do much more than that. Quite bored, he starts fiddling with his cell phone, but can't concentrate. Every time I type, there is a spelling mistake. It's very unpleasant and it's always a countdown until it's over."

Although the use of high tents is permitted by WADA, they have caused concern in the past and WADA considered banning them in 2006. The organization's ethics committee determined that it was "probably against the spirit of the sport," but no action was taken.

Last year, Kampenaerts spent several months at high altitude in Namibia before his attempt at the world time record, but the 1,800-meter altitude he experienced in the African country pales in comparison to his recent artificial efforts.

"Hopefully, it will be a little better again," Kampenaerts said of the high altitude tent and mask. I'm going to sleep in the tent sometimes to prolong the effect." The preliminary results were very good. I broke all the wattage records, but I've heard that from different athletes, so it's not abnormal."

"I've never been able to train for such a long period of time in such a systematic way. If we had done that, it would have paid off."

Campenaerts is targeting the Giro d'Italia in October after the season resumes. He will compete in the Czech Tour, the Belgian Championships, and the European Championships in August before taking on the Settimana Coppi e Bartali, the World Championships, and the Giro.