We can now estimate the effect of blood doping, Alex Hutchinson notes, following the introduction of the Athlete Biological Passport in 2012:
The design of the study was straightforward. Iljukov and his colleagues looked at the top eight times from the Russian National Championships between 2008 and 2017 in the women’s 800, 1,500, 3,000 steeplechase, 5,000, and 10,000-meters. Anti-doping authorities started collecting longitudinal data to assemble biological passports in 2009, and began formally using the technique and applying sanctions sometime around 2011. Figuring that the deterrent effect of the ABP program started after the first bans were handed out, the researchers divided the results into two categories: 2008 to 2012, and 2013 to 2017.
There are a few different ways you can slice and dice the data, and the researchers also looked at other metrics like the number of athletes caught doping in these events and the number of Russian women hitting the Olympic qualifying standard. But the simplest outcome is the average of those top-eight times before and after the ABP. Here’s what that looks like for each of the five events analyzed:
For four of the five events, there’s a significant slowdown, ranging between 1.9 percent in the 800 and 3.4 percent in the 5,000. The only exception is the steeplechase, which was still a relatively new event for women in 2008, when it made its first appearance at the Olympics. The steeplechase also involves hurdling over barriers, which introduces an additional performance variable beyond pure endurance capacity.
One way of interpreting these findings, Iljukov says, is to conclude that for elite athletes, “a significant amount of blood transfusion could improve running times by 1 to 4 percent, depending on the distance, but on average 2 to 3 percent.” The paper compares this estimate with early studies of blood doping in elite athletes, including some old Soviet studies that don’t show up in the usual PubMed searches, which support the idea of a 1 to 4 percent range of improvement from a transfusion of 750 to 1,200 milliliters of blood.
These days, the ABP program makes it difficult to get away with adding that much blood to your system. Instead, would-be cheaters are limited to microdosing with small amounts of blood. Iljukov guesses that this might still give a one-second edge to an elite 800-meter runner—far from fair, but much better than the previous situation. Of course, this deterrent only works if the athletes in question are being regularly tested to generate sufficient data for a biological passport.