The decision to strip Lance Armstrong of his Tour de France titles after he refused to continue fighting claims he took performance-enhancing drugs led to in-depth reporting of the science of doping—but the expert coverage was written largely by sports, not science, reporters.

The United States Anti-Doping Agency (USADA) charged Armstrong with doping and playing a central role in a doping conspiracy while on the United States Postal Service professional cycling team in the 1990s and 2000s. The conspiracy was due to be revealed in a public hearing, but the Texan chose not to contest the evidence collected against him, leaving journalists to evaluate it on their own.

Coverage of the case has followed a general pattern of claim and counter-claim from the USADA and Armstrong. In a statement, the agency said the cyclist had received a lifetime competition ban for “anti-doping rule violations,” including using or attempting to use the banned substances erythropoietin (EPO), testosterone and corticosteroids, as well as undertaking blood transfusions. In response, Armstrong said in a statement that “there is zero physical evidence to support … [the] outlandish and heinous claims.”

Reporting has hinged on evaluation of the evidence and uncertainty underlying the competing claims, a skill that lies at the core of science reporters’ work, but which sports reporters expertly enacted in this case, as they weighed the arguments for and against the cyclist who won seven consecutive Tour de France titles from 1999 to 2005.

Armstrong has always denied using performance-enhancing substances to win his titles. As support for his position, he said the “only physical evidence here is the hundreds of controls I have passed with flying colors.” As support for its decision, the USADA has relied heavily on what it calls a non-analytical positive: instead of the detection of prohibited substance in a competitor’s body, the evidence comes from witness statements or athlete admissions.

This tension between these forms of evidence were the subject of an excellent piece by New York Times sports reporter Juliet Macur, with much of her report based on well-sourced interviews with anti-doping specialists. She quoted David Howman, director general of the World Anti-Doping Agency (WADA), as saying: “Science can’t decide everything … These days, you need to complement a testing program with the gathering of evidence with other methods. To build your case, you put together strands that make one strong rope.”

And along with witness testimony—believed to include many of Armstrong’s former teammates—the anti-doping agency, reported Macur, has biological evidence: results of abnormal blood tests from Armstrong in 2009 and 2010 that the agency says are consistent with doping. Macur quoted Christiane Ayotte, the head of a World Anti-Doping Agency-accredited lab near Montreal: “This is not an adverse finding, but this is certainly a sufficient equivalent to testing positive.”

Macur’s piece also described the difficulties faced by drug testers. As well as having to amass a range of evidence, they face the additional challenge of needing to catch a cheating athlete while the banned substances are still in their system. “For example, oral testosterone and microdoses of EPO will be detectable for only 12 hours. You just about have to be there when the athlete is doping to catch them,” Ayotte was quoted as saying.

Moreover, there are fewer doping cases because the athletes are becoming better at cheating, and are surrounded by people who support their doping. Don Catlin, the former head of the UCLA Olympic Analytical Laboratory, told Macur: “There’s a notion that, oh, they have drug testing, there are no more doping problems in the sport, but unfortunately that is not the case. The testing is just not that good. There are holes. There are loopholes, and we’re constantly trying to plug them … Athletes, particularly the most successful ones, have a complex network of people around them to figure out how to beat the drug tests.”

Much of the reporting placed the allegations against Armstrong in the context of professional cycling in the 1990s and 2000s, a period marred by a succession of doping scandals, during which, The Guardian wrote, a culture of secrecy allegedly existed to protect drug use. Riders’ performances were radically improved at the time by the use of hormones such as EPO, which worked by increasing the amount of red blood cells that transported oxygen, allowing endurance cyclists to ride harder and longer.

Declan Fahy , PhD, is an assistant professor in the School of Communication at American University, Washington, D.C, where he teaches a course in health, science and environmental reporting. His research examines emerging methods, models and styles of science journalism.