In an extensive interview with the French sports daily L’Equipe, Kohl said extractions of blood began nearly a year before competition.
“It was in August, 2007, when I submitted to the first extraction of blood destined to be used in the 2008 Tour. The second was in November, a liter each time,” Kohl told L’Equipe. “I had two liters at my disposition for July 2008. My blood was prepared, the plasma globules separated, coded and frozen.”
Kohl outlined when he would re-inject the blood into his system before key moments of the race, giving his system extra capacity to carry oxygen to his muscles needed to propel him up the torturous mountain roads.
...
Finally, Kohl said efforts of the biological passport have fallen short, and perhaps even aided the more nefarious members of the peloton.
“The top riders are so good at doping that they know what they need to do to keep their blood levels stable to escape targeting,” he said. “In fact, the UCI has shown us the levels of riders who failed tests. We used that as a reference to follow. The passport has almost helped us.”