Victor Kampenaerts (NTT Pro Cycling) revealed that he has been sleeping in a high altitude tent for the past three weeks to keep himself in top shape, despite doing very little training.

The Hour Record holder lives near sea level in Belgium, but the tent allowed him to simulate the atmospheric conditions of high altitude.

In an interview with Belgian broadcaster Sporza (opens in new tab), Campenaerts suggested that he was able to mimic the benefits of doping with EPO and said he was aiming for "an unprecedentedly high hematocrit."

High altitude tents, also known as hyperbaric or hypoxic chambers, are allowed under World Anti-Doping Agency rules but are banned in some countries, including Italy and Norway.

High altitude training camps typically sleep at 2,000 m or higher, but Kampenaerts went to the extreme by pitching his tent at 4,700 m.

"It is not unusual to see people sleeping in tents at high altitudes," he said.

"It is of course very high," he told Sporza (open in new tab). 'Medically, that's just about the height at which you don't start dying. Any higher and the body starts to break down because it's too heavy.

"But 4,700 meters is also a height at which the body is extremely active to produce red blood cells and yet has enough energy to do so.

Conditions were so tough that Kampenaerts could barely ride his bike.

"I rode my bike less hours than the average cycling traveler during that period. I rode only eight hours a week," he says.

"But after a few weeks in the high altitude tent, I became super strong. You'll feel like an athlete who took EPO because you've built a lot of red blood cells; an athlete who took EPO would have run hard for three weeks, but I just barely cycled for three weeks."

Campenaerts considers this practice a success and continues to prepare for the delayed 2020 season by setting his tent at a lower elevation.

"I want to start my last training block for the season with a higher hematocrit level than ever before," he said. Hematocrit is the concentration of red blood cells in the blood and was previously used as an indicator for EPO use.

Despite being permitted by WADA and used by many professional cyclists, the high altitude tent has raised concerns because of its propensity to artificially cause physiological changes in the body.

In 2006, WADA considered a ban after its Ethics Committee determined that it was "probably against the spirit of the sport," but no action was ultimately taken.

A few years ago, Marc Serge, the boss of Lotto Soudal, said of Thomas De Gendt's use of the chamber: "Where do you draw the line? Is it okay to use a home trainer? You can run on a home trainer instead of on the road, and the opposition can say, 'That's unethical. I don't think it's a big issue.'