A high-level cyclist as a teenager, he gave up racing at 17. He married, had children, divorced and worked at a series of tattoo parlors.

But after watching Armstrong on television in that 2004 Tour, Leogrande began riding again. Despite his long layoff, he was still a talented rider, and the next year, he was signed by a professional team.

By this point, however, the landscape of competitive cycling had shifted drastically from the one Leogrande had departed a decade earlier. When he began to race competitively again, other professionals started talking to him about doping.

“They would just talk about it in the way that most people would talk about eating healthy,” Leogrande said. “I immediately knew I shouldn’t do it. I knew there would be consequences. But I was strangely attracted to it at the same time.”

He added, “I wanted to see what the effect would be.”

Leogrande said he first bought EPO in late 2006 from Joe Papp, a former pro cyclist who has since pleaded guilty to distributing performance-enhancing drugs. Without a doctor to advise him, Leogrande was not sure how much EPO to take, or when to take it. The first few times he took it, he said, it left him feeling as if he had the flu.

In 2007, he signed with the Rock Racing team, where he was introduced to former teammates of Armstrong’s. He also began doping more regularly, he said.

Leogrande said he continually felt like a child skipping school. After training rides, he would study every car parked by his house, worried that drug-testing officials were waiting for him.