Doping tests are reported as though they were a single event: an athlete provides a sample, a laboratory says yes or no. The reality is a chain of custody, two separate samples, a review process and a hearing, and each link exists because a case has to survive legal challenge. That is why results take months and why the process looks slow from outside.
Written September 2026. Describes the World Anti-Doping Code framework, which most international sports follow.
When and how doping tests are collected
Testing splits into two kinds, and the second is where most detections happen.
- In-competition testing, around an event. Predictable, which limits what it catches, since many substances are used in training rather than on competition day.
- Out-of-competition testing, unannounced, at home or in training. This is the genuinely effective form, precisely because it cannot be planned around.
An athlete is notified and then kept under continuous observation by a chaperone until the sample is provided. Urine collection is directly witnessed, which athletes describe as the most objectionable part of the process and which exists because substitution was once common.
The whereabouts requirement
Athletes in a registered testing pool must supply their location for every day, including a specified one hour window when they can definitely be found. Three missed tests or filing failures within twelve months counts as an anti-doping rule violation in itself, with the same consequences as a positive result.
This is the part outsiders find harshest and anti-doping bodies consider essential. Without it, unannounced testing would be impossible, and the system would collapse back to predictable in-competition sampling.
The A and B sample system
Every collection produces two sealed samples from the same specimen, labelled A and B, coded rather than named so the laboratory does not know whose they are.
- The A sample is analysed. If nothing is found, the process ends and the B sample is eventually destroyed.
- If a prohibited substance is found, this is an adverse analytical finding, not yet a positive test in any formal sense.
- The result is reviewed against the athlete’s therapeutic use exemptions, since many prohibited substances are legitimate medicines with an approved exemption.
- The athlete is notified and may request analysis of the B sample, and may attend or send a representative to observe it.
- If the B sample confirms the A, the case proceeds to a disciplinary process. If it does not, the case is closed.
Why sanctions vary so widely
Two athletes testing positive for different substances can receive very different outcomes, which looks inconsistent and follows clear rules.
- Intent matters. A deliberate violation attracts a substantially longer ban than one an athlete can show was not intentional.
- Substance category matters. Specified substances, which are more plausibly present through contamination or ordinary medication, carry more flexibility than non-specified ones.
- Contamination is a real defence and a hard one. Athletes must establish the source, which is expensive and frequently impossible.
- Cooperation can reduce a ban, where an athlete provides substantial assistance in uncovering wider wrongdoing.
The biological passport
Not all cases begin with a substance being detected. The athlete biological passport tracks blood and steroid markers over time and looks for patterns that are physiologically implausible without intervention. It can support a case even when no prohibited substance is found in any single sample, which is how some blood doping is caught.
Why it takes so long
From collection to a published sanction, a contested case commonly takes many months. Laboratory analysis, B sample confirmation, results management, the athlete’s right to a hearing and the possibility of appeal to the Court of Arbitration for Sport each take time. The delay is not inefficiency: a case that skips these steps does not survive appeal, and an overturned sanction is worse for the sport than a slow one.
For related reading on how sporting bodies make and defend contested decisions, our explainer on how the Ballon d’Or is voted on covers a very different process with the same problem of legitimacy, and how to read a batting slump covers reading performance data without jumping to conclusions.
What is actually on the prohibited list
The list is revised annually and is broader than most people assume. It covers anabolic agents, hormones and growth factors, beta-2 agonists, hormone and metabolic modulators, diuretics and masking agents, along with prohibited methods such as blood manipulation and gene doping.
Two points cause most inadvertent violations. Some substances are banned in competition only, so timing decides whether a medication is a problem. And diuretics are banned not because they enhance performance but because they can mask other substances, which surprises athletes taking them for genuine medical reasons. Strict liability applies throughout: an athlete is responsible for what is in their body regardless of how it arrived, which is why supplement contamination remains a persistent source of cases.
Therapeutic use exemptions
Athletes with genuine medical conditions can apply for a therapeutic use exemption, allowing a prohibited substance where there is no reasonable alternative and no performance advantage beyond returning to normal health. Applications are assessed by an independent panel and, for common conditions such as asthma, are routine. Where exemptions become controversial is in the grey zone: a legitimate exemption can still confer an edge, and disclosure of exemptions through leaks has caused several public disputes without any rule being broken.
Who pays for all this
Anti-doping is funded by a mix of governments, international federations and the International Olympic Committee, and the budgets are smaller than most people assume relative to the sums circulating in professional sport. That constrains how many doping tests can be conducted, which is why testing is targeted using intelligence, competition calendars and biological passport data rather than spread evenly. It also explains why detection rates vary so much between sports and countries: the difference often reflects how much testing happens rather than how much doping does.
Common questions
Why are there two samples in doping tests? The A sample is analysed first. If a prohibited substance is found, the athlete can request the sealed B sample be tested to confirm it. Without confirmation, the case does not proceed.
What is the whereabouts requirement? Athletes in a registered testing pool must provide their daily location and a one hour window when they can be found. Three missed tests or filing failures in twelve months is itself a rule violation.
Why do some bans last longer than others? Sanctions depend on whether the violation was intentional, which substance category was involved, whether contamination can be proven, and whether the athlete assisted a wider investigation.
What is the athlete biological passport? A record of blood and steroid markers tracked over time. Patterns that are physiologically implausible can support a case even when no banned substance is detected in a single sample.
Sources and further reading
Where the figures and rules above come from, so you can check them:
- The World Anti-Doping Code and testing standards: WADA
- Appeals and arbitration in sport: Court of Arbitration for Sport
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