Understanding the Biological Passport: The Most Powerful Anti-Doping Tool of Professional Sport

“We are seeing a major change at the top level of the sport. We’re all aware that cycling has a doping problem and for 40 years has been dealing with a doping problem.”

That’s what former UCI president Pat McQuaid said in 2008 when the governing body rolled out its Athlete Biological Passport.

It was a landmark moment born out of a dark age defined by blood bags, EPO shots, and murky “preparation” protocols.

In the 18 years since, the Athlete Biological Passport (ABP) has been adopted by the World Anti-Doping Agency and become the most powerful anti-doping tool of professional sport. It’s busted hundreds of endurance, strength, and track-and-field athletes.

And the ABP’s muscle is as clear and crucial in this modern era of superhuman cycling performance as it ever has been.

Just last week, two entire pro cycling teams were suspended after multiple passport violations within their roster. Four months before that, Red Bull racer Oier Lazkano was suspended in what was one of the most high-profile doping cases of modern times.

But here’s the thing.

There’s typically no “gotcha” under the ABP system. It doesn’t catch athletes “red-handed” to definitely prove they’ve been smashing steroids or blowing their budget on blood enhancers.

Instead, the biological passport relies on an “indirect” method of oversight that’s caused controversy since day 1.

Confused? Curious?

Don’t worry, you’re not alone. The ABP is one of the most misunderstood systems in elite sport.

That’s why we’re going to break it down.

What is the Athlete Biological Passport?

An athlete’s passport is a long-term, ongoing profile of their blood and steroidal markers, as collected during in- and out-of-competition blood and urine testing. An endocrinological module was also recently added to the ABP dashboard.

Key markers monitored by the ABP include all the big hitters you’ve likely heard of, and more. Hematocrit [remember the 50 percent rule?], hemoglobin, red blood cell count, and testosterone are all in there.

Every athlete who falls under a sporting federation’s “testing pool” has their own biological passport.

In cycling, the passport is mandatory for athletes racing in the men’s and women’s WorldTour and second-division Pro Series. Those who register for an attempt on the UCI Hour Record also must become part of the pool.

Local federations determine whether their continental-level riders are required to be a part of the program.

The UCI has delegated all testing and results management of its passport program to the International Testing Agency (ITA). The Switzerland-based agency is an independent body that manages anti-doping programs across dozens of sports.

How the biological passport works

The blood, steroid, and endocrine panels of an athlete’s passport are monitored by algorithms that detect spikes or trends that breach reasonable limits.

The ABP uses a so-called “adaptive model” that creates thresholds individual to each athlete, based on their unique biomarker history. Limits for you will not be the same as they are for me.

This algorithmic model is the first layer of the ABP’s monitoring system.

It’s used to alert an independent “Athlete Panel Management Unit” of blips, spikes, and trends that surpass the gains to be had from just hard workouts, hypoxia, or heat training. Or as WADA would call it, of “possible enhancement or manipulation.”

This team of physiology and medical experts is required to dive deeper into the anomalies spotted by the ABP algorithm.

In some cases, what appears to be a violation may have a valid reason. If not, the management unit escalates the case to WADA and the UCI.

The UCI then contacts the rider for an explanation before they potentially open disciplinary action.

Sanctions dished out to athletes vary depending on the case.

In many instances, an offender will be suspended from racing. This can trigger the rider to be axed from their team – as Lazkano discovered the hard way last winter when he was terminated by Red Bull-Bora-Hansgrohe.

A passport violation is not always the end

This “indirect” method of busting dopers was initially received with shock and skepticism.

Some athletes with a passport violation are sanctioned without ever being “caught red-handed” by a positive test. Others might pop after the anomalies in their profile make them the subject of enhanced dope testing.

But of course, a sanction isn’t always the end of the story.

For example, Alberto Contador’s lieutenant Roman Kreuziger had his passport case overturned by the Czech Olympic Committee in 2014, and he was welcomed back from exclusion by Team Tinkoff Saxo.

At the time, it was a high-profile case that put the credibility of the ABP into the spotlight.

Two years later, Sergio Henao was notified of an anomaly in his passport while racing with Team Sky, but was cleared by the UCI.

Some athletes who don’t see such a timely reprieve stump up for the costly and protracted process of an appeal to the Court of Arbitration for Sport (CAS).

In 2024, former No.1 tennis player Simona Halep saw her ban slashed from four years to 9 months after she successfully pleaded “contamination” to CAS. The global superstar had tested positive for blood boosters after passport irregularities triggered more targeted testing.

But not everybody has the financial heft to take a case to CAS.

Former “most combative rider of the Tour de France” Franck Bonnamour retired under the dark cloud of an ABP violation in 2024 while still protesting his innocence.

“The defense of this case is too expensive,” Bonnamour told Ouest-France. “I’m stopping. I can’t afford to lose everything.”

WTF are all the acronyms? Glossary of terms

Struggling to keep up with all the acronyms? We get you, and we’re sorry.

Here’s a handy guide to help you keep track:

• ABP: Athlete Biological Passport
• ADAMS: Anti-Doping Administration and Management System
• CAS: Court of Arbitration for Sport
• ITA: Independent Testing Agency
• UCI: Union Cycliste Internationale
• WADA: World Anti-Doping Agency

The importance – and pressures – of the whereabouts system

The “whereabouts” system underpins the Athlete Biological Passport.

Every three months, all athletes in the testing pool are required to submit details of their daily location. This is captured in the Anti-Doping Administration and Management System (ADAMS), and becomes the trail that drug testers follow.

The level of detail required for “whereabouts” is wild.

Athletes provide locations for every 60-minute window between 6 am and 11 pm, 7 days a week. Travel details, hotel information, and even personal property access codes must also be included.

It means riders might get an unexpected knock while they ponder their third bowl of morning oatmeal or as they nestle down for a night of Netflix.

Being available for these out-of-competition tests has to be even more of a priority for an athlete than the timeliness of their Strava log or the perfection of their next Insta post.

Racers under the UCI code face sanction if they repeatedly fail to complete their whereabouts data or are not in-location for a surprise test.

The whereabouts model has been widely criticized.

Delayed flights, mid-training mechanicals, and emergency missions out of home could be consequential.

In fact, riders’ union president Adam Hansen recently told Domestique that cyclists are at the point where they’d prefer to be fitted with GPS trackers than continue with the current system.

Biological passport cases: No.1 tennis players, leading marathoners, entire cycling teams

The ABP is a term many sport fans are familiar with, but few realize the extent of its impact. Many of the biggest doping cases of the past 18 years have been a result of its system.

Thomas Dekker and Danilo di Luca were among the first cyclists who were sanctioned because their bio passport was going bonkers.

Since then, Dennis Menchov, Franco Pellizzoti, Jonathan Tiernan-Locke, and Robert Stannard have been involved in high-profile ABP cases.

Other cases you may remember involve entire teams being banned under UCI rules that govern two passport violations within a single team.

The “two strikes and out” system last week barred the entire Medellín and Feirense teams from racing, and has previously whacked lower-tier Italian teams Androni Giocattoli, Bardiani CSF, and Vini Zabù, as well as the Portuguese conti crew, Tavira.

The ABP hasn’t only had a huge impact on pro cycling. It’s cleaned up scores of Olympic sports.

Team USA swimmer Michael Brinega, record-breaking Kenyan runner Rhonex Kipruto, and London Marathon winner Daniel Wanjiru are in the ABP’s black book.

Tennis topper Halep is perhaps its headline scalp.

The biological passport is not perfect – but it’s the best that sport has got

The ABP is very much a part of modern sport, but it’s no perfect solution.

Most obviously, there’s no “gotcha” of a positive test.

And beyond that, the system is only as worthy as the algorithms that form its front line. It’s understood that these are constantly being refined to iron out old creases and cater for new doping developments.

Beyond the algorithm, a suspect athlete’s future depends on the knowledge and experience (or lack thereof) of the human team assessing their case.

And the challenges are perhaps greater outside of the ABP system itself.

The developments in sports science that led to transformational high-carb fueling protocol and precision altitude workouts can also inform more sophisticated microdosing strategies or the better use of masking agents such as diuretics.

And even where the ABP is effective, teams do not have access to its data.

Current legislation rules that a rider must sign off before a team or anyone else can see their profile. As Velo explored with reference to Lazkano, this means teams might continue to race a rider who’s under active UCI investigation.

And what of the continental ranks?

The MPCC “clean cycling” group noted in a recent report that doping cases are most prevalent at this third tier of cycling – the very level where the ABP is not mandatory.

Power passports, progression profiles, and the future of the ABP

There’s consensus that the ABP needs to develop as fast as the sports it safeguards.

The UCI specifically stated its hope that the new endocrine module will address gaps in detecting human growth hormone. A paper published by Frontiers in Sport highlights how alternative blood sampling methods and supplementary biomarkers in the ABP dashboard would help smooth out other wrinkles in the system.

And guess what?

Artificial Intelligence will inevitably play a role in the future of the biological passport. There’s long been chatter of how competitive results or power numbers could be added to the existing model to predict “reasonable,” unenhanced rates of career progression.

In fact, a take on this AI piece could be coming to pro cycling, fast. The UCI is already deep into trials of a “power passport” that tracks a rider’s kilojoule training workload over time to chart a feasible rate of physiological development.

Of course, riders are already getting their bib straps in a twist over the perils and pitfalls of a peloton policed by power data.

But that’s a symptom of a wider problem.

Stakeholders will always find dirt to sling at some existing element or future extension of the ABP. There is no perfect anti-doping tool, after all.

But those critics also cannot deny that the Athlete Biological Passport is making sport cleaner.