Atypical Profiles

An atypical profile in the Athlete Biological Passport (ABP) occurs when statistical analysis of repeated blood or urine samples shows that the measured biological markers no longer match the athlete's individual long-term profile. In cycling, this finding is not an automatic proof of doping – however, it is the central trigger for in-depth investigations, targeted follow-up controls, and in serious cases for disciplinary proceedings.

While classic testing procedures aim to directly detect prohibited substances in a single sample, the Biological Passport works with probabilities, trend lines, and comparative values. The functioning of the system provides the technical foundation; atypical profiles are the practical outcome of this long-term monitoring.

What does "atypical" mean in the Biological Passport?

In anti-doping jargon, a distinction is made between a normal profile, an atypical profile (Atypical Passport Finding, APF), and in rare cases an adverse profile (Adverse Passport Finding, AAF). The terms sound similar but have different legal and sports medicine consequences.

Atypical Passport Finding (APF)

An APF signals: The measured values deviate statistically from the athlete's previous profile, but are not yet so extreme that manipulation must be assumed immediately. Typical triggers are:

• Unusual fluctuations in hemoglobin, hematocrit, or reticulocytes
• Atypical OFF-Score curves without a plausible training or altitude camp explanation
• Steroid profile changes in the urine-based module

With an APF, additional controls typically follow, a request for medical explanations, and a renewed statistical assessment by the WADA Expert Panel.

Adverse Passport Finding (AAF)

An AAF is the more serious finding. Here the Expert Panel concludes that the deviation most likely cannot be explained solely by natural fluctuations, illness, or permitted therapies. An AAF can form the basis for disciplinary proceedings – even without a positive individual test for EPO, testosterone, or other prohibited substances.

Key markers for atypical hematological profiles

The hematological module is most frequently relevant in cycling because blood doping and EPO abuse historically represented the greatest integrity risks – also visible in the major doping scandals of the 1990s and 2000s.

OFF-Score as an early warning system

The OFF-Score combines hemoglobin and reticulocyte values in a single index. It is particularly sensitive to short-term blood manipulation:

1. After EPO administration: Reticulocytes rise, Hb rises with a delay – characteristic pattern
2. After autologous transfusion: Hb jumps, reticulocytes often fall atypically
3. After stopping EPO: Reticulocytes drop abruptly while Hb may still be elevated

An OFF-Score outside the individual reference band is one of the most common reasons for an APF in professional cycling.

Hematocrit and hemoglobin limits

In addition to statistical profile analysis, absolute limits still apply at UCI races (historically around 50% hematocrit for men as a start ban threshold). A profile can be atypical without the athlete being banned on a race day – and conversely, a limit can be exceeded without the long-term profile already being marked as an APF.

Steroid module: Atypicalities in the hormone profile

The steroidal module evaluates urine samples over months. Atypical profiles here often arise more subtly than in blood work:

• T/E ratio (testosterone to epitestosterone) outside the individual profile
• Changes in steroid metabolites indicating exogenous supply
• Isotope ratios distinguishing synthetic testosterone from endogenous

Profile deviations in the steroid module led in the past to proceedings that concluded without a classic positive test – a paradigm shift that the WADA Code has legally secured since 2014.

The evaluation process: From sample to finding

Step 1: Sample collection and quality assurance

Samples must be collected according to standardized testing procedures. Errors in storage, transport, or analysis can distort profiles – which is why there are strict chain-of-custody controls and B samples.

Step 2: Statistical modeling

Each athlete receives an individual reference band, not just a global norm value. The system takes into account:

• Number and frequency of previous samples
• Seasonality and training periods
• Natural biological variability

The more valid samples are available, the more precise the profile becomes – and the more meaningful a deviation.

Step 3: Expert Panel and athlete hearing

The WADA Athlete Passport Management Unit (APMU) and independent experts evaluate atypical profiles. Athletes can submit medical records, altitude camp documentation, or Therapeutic Use Exemptions (TUE).

Consequences for cyclists

The legal and sporting consequences depend on the severity of the finding:

Possible measures for APF:

• Intensified control program (more frequent unannounced tests)
• Request for medical documentation
• Observation over several months without public disclosure

Possible measures for AAF:

• Initiation of disciplinary proceedings by UCI or national anti-doping agency
• Temporary suspension during the investigation
• Sanctions of up to four years for confirmed manipulation – comparable to positive substance tests

Known case patterns in cycling

Historically, atypical profiles became visible primarily in contexts that also played a role in famous doping cases:

1. Micro-dosing of EPO – small doses that evade individual tests but change the reticulocyte-Hb pattern over weeks
2. Autologous blood transfusion – no direct substance detection, but typical Hb jumps and RET% drops
3. Testosterone patches or gels – steroidal profile deviations without classic T/E limit exceedance
4. Combination of multiple methods – parallel changes in hematological and steroidal modules

Limitations and points of criticism

Atypical profiles are powerful but not flawless. The following points are discussed in expert debate:

• Sample density: Athletes with few samples have wider reference bands – atypical patterns are harder to detect
• Individual physiology: Rare anemic or polycythemic conditions can distort profiles
• Altitude training: Legal altitude camps can shift values toward doping patterns – requires clean documentation
• Rule of law: Burden of proof and the right to a hearing must be preserved

Practice: What teams and athletes should consider

Professionals under UCI license are required to keep their whereabouts in ADAMS up to date – without precise whereabouts, targeted unannounced controls and valid profiles are hardly possible.

Checklist: Preparing for possible profile inquiries

Comparison: Atypical profile vs. classic positive test

Outlook: Smarter profile evaluation

WADA and UCI are working on refined algorithms that should more strongly incorporate training data, altitude exposure, and individual genetics. The goal is to reduce false positives while detecting micro-dosing strategies earlier. For cycling, the atypical profile thus remains not just a technical detail – it is a central instrument to regain the trust of fans, sponsors, and athletes after the experiences from doping scandals.

Frequently asked questions about atypical profiles

Is an APF equivalent to doping?

No. An APF signals a statistical deviation that requires in-depth review. Only with an AAF or after a successful disciplinary proceeding is a confirmed violation established.

Can altitude training trigger an atypical profile?

Yes, legal altitude camps can increase hemoglobin and hematocrit. Athletes should document stays; the Expert Panel checks whether the patterns match altitude training.

How long does an Expert Panel procedure take?

Depending on complexity, several weeks to months – including hearing, medical statements, and renewed statistical evaluation.

Are atypical profiles made public?

APF findings generally remain confidential. AAF and disciplinary proceedings are often only made public after charges or notification by the anti-doping organization.

Can an athlete appeal an AAF finding?

Yes. Athletes can appeal to sports courts (CAS) and raise medical as well as procedural objections.