The core concept of the Athlete Biological Passport (ABP) is to monitor changes in an athlete's biological parameters over time. The ABP is an individualized profile that records and compares biological markers (biomarkers) which may indicate the use of prohibited substances or methods in sport.
ABP biomarker values are unique to each athlete: comparisons are made not against population-based reference ranges, but against the athlete's own baseline values. Therefore, a fundamental requirement of the ABP is the systematic accumulation of data and longitudinal analysis of changes with each new sample.
Currently, the ABP comprises three modules: haematological, steroidal, and endocrinological. Each module targets the detection of substances and methods that are difficult to identify through conventional analytical approaches:
- Haematological module – designed to detect the use of erythropoiesis-stimulating agents (e.g., EPO) and blood transfusions. Whole blood samples are analysed;
- Steroidal module – designed to identify the use of anabolic androgenic steroids and sample substitution. Urine samples are analysed;
- Endocrinological module – designed to detect the use of growth hormone. Blood serum samples are analysed.
WADA-accredited laboratories (or those specifically approved for ABP analysis) process ABP samples and upload the encoded biomarker data into the ADAMS system. The system analyses longitudinal changes in the athlete's profile and flags any atypical variations. To interpret ABP data that may suggest a doping scenario, each anti-doping organization engages highly qualified, independent experts.
Based on ABP findings—even in the absence of a traditional adverse analytical finding—an anti-doping rule violation case may be initiated against an athlete under the provision "Use or Attempted Use of a Prohibited Substance or Prohibited Method" (Article 2.2 of the World Anti-Doping Code; Article 4.2 of the RUSADA Anti-Doping Rules).
Additionally, information derived from the ABP may inform testing planning (e.g., targeting specific athletes for testing, placing samples into long-term storage, ordering additional analyses) or support investigations into potential anti-doping rule violations.
