Going to put together my best argument for why Sabastian Sawe was not using performance enhancing drugs during his sixty day buildup to the Berlin Marathon discussed in the article.
Let's start with EPO, the most common method of doping in distance running. Brett Clothier, the Head of the AIU (annoyingly not formally introduced in the article), says "Microdosing EPO might only be detectable for a day or two," let's take the low end of that and assume a 24 hour window for detection. If an athlete microdoses EPO once per week with a 24 hour window for detection, an out of competition test will have a one in seven chance of catching them. However, the athlete can manipulate the whereabouts system to avoid two potentially positive tests per year (this is not without risk, Diribe Welteji was caught trying to avoid a test). This means an athlete microdosing EPO once per week is most likely to be caught between tests 15 and 21 in a year. This lines up with available evidence on how often Shelby Houlihan and Ruth Chepngetich were tested.
In contrast, Sawe was tested 25 times in 60 days. He presumably did not miss any tests in that window, given that he invited the testing. So, if Sawe were microdosing EPO with a 24 hour detection window, each dose would present a 41% chance (25/60) of being caught. If he microdosed once per week (8 times total) as in our hypothetical above, he would have just a 1.3% chance of passing every test. It is vanishingly unlikely that Sawe was microdosing EPO during this time.
Now, there are substances with shorter detection windows. "Testosterone or similar substances with anabolic properties" are what Clothier cites specifically in the article. However, testosterone, along with other steroids, is part of the Athlete Biological Passport's (ABP) steroidal module. Per WADA "The ABP intends to establish that an Athlete is manipulating his/her physiological variables, without necessarily detecting a particular Substance or Method." In other words, no individual positive test is required. A huge number of dopers, including recently Rhonex Kipruto, have been caught by the ABP. While WADA notes that "For the Haematological Module, data points are most statistically independent when Samples have been collected at least five (5) days apart," they do not say this about the steroidal module. If Sawe had been manipulating his steroid levels, with this level of testing his ABP would almost certainly show it.
People will say that a new undetectable drug has emerged, and that is what Sawe was taking. That is technically possible. But I will ask this: if Claudio Berardelli had an undetectable PED, why would he have so many athletes suspended?
Sabastian Sawe won the 2025 Berlin Marathon by over 4 minutes. And we can be reasonably sure that he did not use any known PEDs during his sixty day marathon build. Of course, it is always possible that he may have doped before or after that time period, but as Gault notes Berlin was his best marathon. Gault describes Sawe's Berlin run as "one of the most encouraging anti-doping stories in the history of marathon running," and I think that's clearly correct.
Source for ABP WADA quotes: https://web.archive.org/web/20131212201604/http://www.wada-ama.org/Documents/Science_Medicine/Athlete_Biological_Passport/WADA-ABP-Operating-Guidelines_v4.0-EN.pdf.
