Team Bath's director of sport Steve Baddley has revealed Great Britain silver medalist Michael Jamieson prepared for his swim by sleeping in an altitude chamber.
Fellow finalist and Team GB swimmer Andrew Willis also used the tents, which trigger the body to create more oxygen to fuel training.
"They've been set up in the bedrooms," Baddley told BBC Radio Bristol.
"One was sleeping at 2,800m and another at 2,400m."
Athletes have long been training at high altitudes in a bid to increase endurance levels.
In 2006, the World Anti-Doping Authority (WADA) decided not to ban altitude machines even though there are benefits without effort, and the hypoxic chambers are now being installed outside of training centres.
Earlier this year US swimmer Michael Phelps, the most decorated Olympian of all time, revealed he had altitude tent built in his bedroom in his apartment in Baltimore.
Baddley continued: "It's used to thin their blood out and increase the red blood cell count and get themselves in top condition.
"So, rather than travelling out to the Pyrenees and finding a 50m pool up high, they've brought the tents into their bedrooms.
"It sounds slightly quirky but the coach said that whether it works physically or mentally, I doesn't matter. If they believe in it, then that's the main thing."
In his debut Olympics, Scotsman Jamieson smashed his own British record to win silver in the 200m breaststroke final in London on Wednesday.
Willis, his training partner at Bath, could only finish in eighth but Baddley says the pair's close friendship has aided them throughout their preparation.
"They trained together in Paris before coming to Bath," said Baddley.
"They live together, they train together and they push each other on.
"They're also very competitive and you can see that rivalry. It's a positive rivalry which has taken them to greater heights."