Medical staff with Russia’s national team have denied allegations that the country’s players took substances to increase their fitness levels during the World Cup.

After Russia’s loss to Croatia on Saturday, Germany’s Bild tabloid published an article alleging that the team had inhaled smelling salts in the dugout of Sochi’s Fisht Stadium during the game. The ammonia inhalants, which are not illegal, could have helped the Russian players increase their “respiratory stimulation” and “improve oxygen supply,” Bild reported.

The Russia team’s head doctor, Eduard Bezuglov, told the Sport-Express newspaper that the players had used the ammonia-based inhalants “to perk up.”

He added that the mixture has been used for decades by “thousands of athletes” around the world and could be purchased at pharmacies.

Pualino Granero, a fitness coach for Russia’s team, said the allegations “could only have been thought up by an idiot.”