One sports medicine expert believes Cohen's paper has missed the mark.
While it's true that few top-level cyclists or endurance athletes have participated in clinical trials to administer EPO drugs, that doesn't mean they don't work, said Michael Joyner, anesthesiologist at the Mayo Clinic in Rochester, Minn. Joyner studies the physiology of elite athletes and developed models of human performance.
There have been many studies showing that EPO boosts the level of VO2 max, or the maximum amount of oxygen taken up and used by the body.
"It's like a red line in a car," Joyner said about the difference between elite athletes and those participating in the previous EPO studies. "The red line is the same, but if you give them more horsepower (in this case EPO), you're going to go faster," said Joyner.
Some sports authorities in the 1980s said that there was no evidence that steroids enhanced athletic performance, despite athletes claims to the contrary, Joyner noted. Once the studies were done, "it was clear that (steroids) worked," he said.