“I can't explain what I see on the road” - Doping shadows cycling once more as German documentary reopens old wounds

More than a decade after the Lance Armstrong scandal threatened to destroy the credibility of professional cycling, the sport finds itself once again under scrutiny. A new documentary by German broadcaster ARD, Geheimsache Doping: Im Windschatten (Secret Case Doping: In the Slipstream), suggests that while the methods may have evolved, the culture of cheating has not entirely disappeared.

One could argue the sport has never truly emerged from the dark cloud of doping, always troubled by rumours of cheating. The question is, are they to be believed? And if these rumours are to be believed, can cycling endure another doping scandal?

The film presents testimonies from several whistleblowers inside the sport, including former professionals, who risked their safety to speak out. “Many people are afraid to talk,” says one ex-pro. “I know someone who wanted to testify, but he received death threats when the masterminds behind doping found out he wanted to talk.”

It’s a chilling reminder of how deep the roots of doping still run, despite claims of a cleaner peloton in the post-Armstrong era. Armstrong’s case, built on EPO, blood transfusions, and systematic deceit, shook the sport to its core, before he was ousted by the likes of Tyler Hamilton. But in exposing the scale of the fraud, it also reinforced just how advanced and coordinated doping operations had become. Cycling introduced the biological passport and increased out of competition testing, but the new revelations suggest those measures might still fall short.

According to the documentary, EPO remains in use, not in the same large doses seen in the 1990s and 2000s, but through microdosing, a method designed to fly under the radar of modern testing. More concerning still is the apparent widespread use of Aicar, a drug that is both hard to detect and immensely beneficial in endurance sports.

“People who are active in professional cycling say that Aicar was and is the drug of choice in the peloton,” says a whistleblower.

Aicar enhances blood flow and can alter muscle fibres, giving an unnatural edge in long, gruelling races, making it perfect for cycling. Its growing use reflects the constant game of cat-and-mouse between dopers and anti-doping authorities. As Oliver Catlin, an American doping expert, puts it: “If I were an athlete, would I take Aicar, knowing that it is on the list of banned substances? Or would I take a related product that is not on the list?”

Even those within the industry admit the Pandora’s box has not been shut, and perhaps is still very much open. “It opened a door that has never been closed,” says Evans, referring to the doping culture that once engulfed the sport.

The documentary doesn’t just highlight the drugs themselves but questions the physical plausibility of what fans witness on the road. Pierre Sallet, who has long studied human performance limits, is blunt. “We know the limits of human performance. We know what a person can and cannot achieve. There are certainly grey areas, but it becomes black and white at some point, and then it's doping, 100%.” He adds: “I can't explain what I see on the road. A normal man is between 1.60 meters and 2.20 meters tall. But the performances we see are sometimes as if someone is 3 meters tall.”

Not everyone agrees that performance gains are due to doping. Some argue that technological progress, from bike design to nutrition and data analytics, accounts for much of the change. “The major developments are much more important than the advantages of illegal substances in the past,” says Filippo Galli, product developer at Colnago. “We are talking about countless innovations: materials, aerodynamics, weight, bike control, grip, comfort.”