How does the biological passport actually work?

November 28, 2025

For all of its importance in the fight against doping, the biological passport often does its work in the background. Pro bike racers certainly spend plenty of time in testing, but the results of those tests rarely make waves.

Under precedent set over a decade ago, sufficiently abnormal values in an athlete’s biological passport can be evidence enough to lead to sanctions. Compared to adverse analytical findings for banned substances, passport-based sanctions are relatively rare at pro cycling’s highest level; before Lazkano, the last WorldTour rider suspended for passport anomalies was Franck Bonnamour in 2024.

Authorities have used the tool sparingly, for a variety of reasons. For starters, only extreme abnormalities even trigger investigation, let alone the determination of likely doping. Moreover, not all cases have led to successful convictions, with Roman Kreuziger in 2014 being a particularly high-profile example of a passport case being overturned. But amid Lazkano’s high-profile provisional suspension for suspicious biomarkers over a three-year period when he was at Movistar, and a second case involving a Continental-level rider, now seems as good a time as any for an explainer on the biological passport.

The tool is a pillar of modern anti-doping efforts, but fans could be forgiven for coming away from the past few weeks of news with questions about the basics. What does the biological passport actually test? How can suspicious findings in an athlete’s passport lead to disciplinary action? And just what, exactly, counts as suspicious? Escape Collective