That list, Dr. Rodchenkov said, guided him in his nightly ritual in Sochi: surreptitiously swapping out the steroid-laced urine of Russia’s top athletes, at least 15 of whom won medals.
An investigation into Dr. Rodchenkov’s account is expected to conclude within days, three weeks before the Summer Olympics in Rio de Janeiro are set to begin, and the full results of the investigation, due on Monday, could prove explosive. Dr. Rodchenkov has cooperated with the inquiry, which was commissioned in May by the World Anti-Doping Agency and has been conducted by Richard McLaren, a Canadian lawyer who was part of a commission that last fall accused Russia of systematic doping.
In a preliminary report last month, Mr. McLaren, who received the Sochi spreadsheet, called Dr. Rodchenkov’s story “both credible and verifiable.”
Last month, global sports officials barred Russian track and field athletes from the Rio Games. WADA has said that if the allegations prove true, it will consider recommending all Russian athletes be barred from competition; Russia’s sports minister, Vitaly Mutko, said he would resign if such a ban were imposed.
In an interview in Moscow this week, Mr. Mutko denied that the government had been involved in any scheme, but expressed concern that his deputy was accused of giving Dr. Rodchenkov direct orders.
Mr. Mutko was alternately confident in Russia’s athletes and contrite about their attitudes toward performance-enhancing drugs. “We have to persuade people you can win without doping,” he said. “It’s the culture. It’s a problem.”
Waiting for the Sochi inquiry to conclude, Ms. Uhlaender, who will turn 32 next week, has fought to keep her focus on the next Winter Olympics, in 2018 in South Korea. Still, she is concerned that sports officials will fail to deliver the rigorous and decisive result she craves.
“I’m worried Sochi will be forgotten, and it scares me,” she said. “Rodchenkov said he tampered with the samples, and there are rules against that. I just want to see them follow the rules.”
Ms. Uhlaender is training in the desert, spending her days lifting weights in Arizona with fellow professional athletes at a high-performance gym and sprinting alongside dozens of other Olympians, mostly track and field athletes preparing for Rio.
Between workouts, there is conversation of all kinds — about high-fat diets, “Game of Thrones,” the price of gas — but there is little mention of the allegations of widespread doping by the Russians.
Ms. Uhlaender said she had talked about the situation twice with her coach. “What are you going to do about it?” he asked her before moving on.
“The worst thing I can do is talk about it,” she said over a chicken lettuce wrap and four shots of espresso. When not training, she meditates; works in education for a traumatic brain injury center, having recovered from a concussion herself; watches Netflix; and exchanges texts with two Navy SEAL friends who have helped keep her tough, she said.
“When I come to train, I don’t want drama,” she said, fiddling with a National League championship ring belonging to her father, the former baseball player Ted Uhlaender. The ring, which she tucks into the back of her sports bra as she works out, hangs on a silver chain alongside a tiny baseball charm that holds his ashes.
One of the few people Ms. Uhlaender has talked to about the doping scandal in recent months is Ms. Nikitina, her Russian competitor. In May, days after Dr. Rodchenkov’s account became public, Ms. Uhlaender and Ms. Nikitina exchanged more than a dozen messages on Facebook.
Ms. Nikitina expressed shock at Dr. Rodchenkov’s statements. “We all think this is politics!” she wrote. “We basically joke about it.”
She added: “Each athlete sure of himself! As we say in Russia, ‘Such complex situations make us stronger.’”
Ms. Nikitina, who did not respond to messages from The Times, told Ms. Uhlaender her name was not on Dr. Rodchenkov’s spreadsheet, and she emphasized the sacrifices she had made to train twice a day to become a better athlete.
When Ms. Uhlaender asked if Russian Olympians had doped at Sochi, Ms. Nikitina said that she could speak only for skeleton racers, and that the answer was no. Dr. Rodchenkov’s spreadsheet listed five Russian skeleton athletes, including Alexander Tretyakov, who won gold at the Games.
Asked about the allegations this year, the Russian Bobsled and Skeleton Federation wrote in an email that all of its athletes “underwent doping control procedures in accordance to the rules,” adding, “All of them were clean, and not one positive result was found.”
Mr. Mutko said in Moscow this week that Mr. Tretyakov and other accused athletes had long careers with clean histories. “These athletes didn’t appear in sport all of a sudden,” he said. “No whiskey would be enough to stop them,” he said, referring to the mixture of steroids and liquor that Dr. Rodchenkov said he developed and distributed to coaches to help Russian athletes absorb drugs more quickly before traveling to international competitions for testing.
Mr. Mutko said, however, that if Mr. McLaren’s inquiry proved Dr. Rodchenkov’s account true, the athletes in question would be disciplined.
“I am not on the list!” Ms. Nikitina wrote to Ms. Uhlaender in a recent exchange. “I hope that the truth will prevail! And the perpetrators of this scandal will be punished!”
Medalists like Ms. Nikitina received high praise for their performance at Sochi. After the Games, President Vladimir V. Putin presented Ms. Nikitina, a first-time Olympian, with a state award, the Order for Merit to the Fatherland.
“Your amazing debut,” Mr. Putin said in a public statement to Ms. Nikitina at the time, “met the expectations of your fans, coaches and teammates.”
Regardless of what may come of the investigation, Ms. Uhlaender called herself more determined than ever to work toward the only major title she has yet to capture in her 13-year career. “I want to win Korea,” she said. “If I’m first, I’ll know no one ahead of me doped.”
She said she felt sympathy for Ms. Nikitina, whether or not the claims against her were substantiated. “She’s going through something, too,” Ms. Uhlaender said. “The shininess has been dulled for both of us.”