A new book on Lance Armstrong's doping conspiracy says that singer/songwriter Sheryl Crow told federal investigators in 2011 about her ex's blood transfusions in exchange for immunity from prosecution. Wall Street Journal reporters Reed Albergotti and Vanessa O'Connell write in Wheelmen: Lance Armstrong, the Tour de France and the Greatest Sports Conspiracy Ever, that while Armstrong and Crow were dating in the mid-2000s, she went with the cyclist to Belgium in 2004 for him to get a blood transfusion, done to help increase the number of red blood cells in his body. Armstrong engaged in both transfusions and doping, both are which are illegal in cycling, often at the same time. The New York Daily News reports that the authors wrote, "Rather than try to hide the transfusion from her, Armstrong was completely open about it. He trusted that Crow would have no desire to tell the press or anyone else about the team's doping program. He explained that it was simply part of the sport, that all cyclists were doing the same thing." The role of Armstrong's closest friends and supporters in helping perpetuate his doping conspiracy is one of the central themes of Wheelmen, which is due out next week.