CAS as the Guardian of the Validity of Anti-Doping Science?

A review of hGH cases through the prism of the revised 2015 World Anti-Doping Code Published 23 July 2015 By: Marjolaine Viret

Syringe and Vial

Over the past decades, doping techniques have continuously grown more sophisticated, and so has anti-doping science. This is especially the case for abuse of substances that can also be produced endogenously by the human body. To keep up with these new realities, anti-doping laboratories have to develop new analytical methods, but also - increasingly - to rely on their scientific expertise for the interpretation of the analytical findings.

This article seeks to provide a thorough but pragmatic perspective on the challenges that panels of the Court of Arbitration for Sport (“CAS”) will face under the 2015 World Anti-Doping Code (“WADC”)1 in dealing with the complexity of anti-doping science. The article takes as a starting point the series of human Growth Hormone (“hGH”) cases brought before CAS during the review and implementation process for the 2015 WADC. It analyses the presumption of scientific validity newly introduced in favour of analytical science (Article 3.2.1 WADC) and the evidentiary implications of this provision, including in its procedural aspects.2


In the above interview Marjolaine Viret talks in detail about trilogy of hGH cases, Article 3.2.1 of the 2015 World Anti-Doping Code and the role of CAS in deciding the scientific validity of anti-doping decision limits.  


A Symbol of Growing Complexity in Anti-Doping Science

Abuse of exogenous human Growth Hormone is seen as a serious issue in anti-doping. This is reflected in the inclusion of hGH as a target – along with EPO and related substances – in the new Technical Document for Sport Specific Analysis (TD2014SSA) enacted by the World Anti-Doping Agency (“WADA”), a document that imposes minimum levels of analysis based on a risk assessment for certain categories of substances in particular sports. It is also reflected in the fact that two different tests for hGH detection have been developed, each with their dedicated WADA Guidelines.3 Generally speaking, the challenge for analytical science lies in distinguishing exogenously administered hGH from hGH naturally (endogenously) produced by the human body.4


Diverging Approaches in CAS awards Veerpalu v. FIS and NADA v. Sinkewitz

During the review and implementation process for the 2015 WADC, two panels of the CAS were called to decide on the scientific validity of the more established of the two hGH tests, the Isoform Differential Immunoassays test for the detection of recombinant hGH (a synthetic form of exogenous hGH).5 In these cases, the debate revolved specifically around the ‘decision limits’, i.e. the ratios used by WADA-accredited laboratories to determine whether to report a Sample positive for the presence of hGH (a so-called Adverse Analytical Finding)6 under the relevant WADA Guidelines. The first panel, in the matter Veerpalu v. FIS,7 refused to find that the Athlete had committed an anti-doping rule violation, since the reliability of the decision limits had been insufficiently demonstrated. By contrast, the second panel, in the matter NADA v. Sinkewitz,8 considered that the presence of hGH can be established irrespective of the reliability of these decision limits, since the decision limits are merely enshrined in - non-mandatory - Guidelines, as a mere “recommendation” to WADA-accredited laboratories, and thus have no “legally binding” value that would delimit the scope of the prohibition.9

The two CAS Panels apparently built their reasoning on different legal perceptions of the ‘decision limits’ inherent in the hGH test.10 Without entering into the technicalities of this test, the Panel in Veerpalu v. FIS appeared to regard the test as a quantitative analysis in which decision limits, though set dynamically by WADA, have a legally decisive value. By contrast, the NADA v. Sinkewitz Panel treated the decision limits as mere technical tools of interpretation that instruct WADA-accredited laboratories when to report the ratios present in the Athlete’s Samples as an Adverse Analytical Finding for hGH, but held that the actual ratios found in a Sample can be shown by any reliable other means of evidence - including expert evidence - as indicating the presence of exogenous hGH and thus an anti-doping rule violation.11

The diverging reasoning in the Veerpalu v. FIS and NADA v. Sinkewitz awards is symptomatic of the general ambiguity of CAS awards on the legal characterisation of the documents codifying scientific procedures and the lack of conceptual clarity on the status of scientific rules under the WADC regime. This points to the difficulty of translating increasingly complex analytical tools into a legal framework that can be easily managed within the limited procedural timeframe available to the CAS panels in doping disputes.12

New Developments In the WADA v. Lallukka Matter

The Veerpalu v. FIS award was rendered in March 2013, during the consultation process for the 2015 WADC review, and attracted much attention within the anti-doping community. The award had a distinct impact on the review process. Beyond the immediate effect of putting on hold the prosecution of hGH cases pending the verification of the decision limits through additional studies commissioned by WADA, the award further resulted in adding to the revised WADC a new presumption of scientific validity of analytical methods and decision limits (Article 3.2.1 of the WADC). The NADA v. Sinkewitz award, rendered in February 2014 shortly after the final adoption of the revised WADC, again considerably modified the legal landscape on hGH issues. The findings in NADA v. Sinkewitz in effect made the Veerpalu v. FIS concerns about the reliability of the decision limits moot, and the award may be viewed as a pragmatic response to the hGH problem. The award was a green light for Anti-Doping Organisations to resume anti-doping proceedings for hGH findings without having to await the blessing of the new decision limits by a CAS panel, provided only the ratios detected in a given matter were sufficiently clear-cut to build a case based on expert evidence.

On 28 November 2014, WADA announced in a press release that a new CAS award involving Finnish cross-country skier Juha Lallukka confirmed that all concerns surrounding the hGH test – in particular those raised in the Veerpalu v. FIS award – were resolved, leaving no doubts regarding the validity and reliability of the newly published version 2.1 of the related WADA Guidelines.13 The full WADA v. Lallukka award was published in early 2015.14

The task of the panel in the WADA v. Lallukka matter was not an easy one, insofar as the Panel was required to make a ruling based on two conflicting precedents.15 In particular, the award was rendered at a time in which the verified decisions limits based on the independent studies triggered by the Veerpalu v. FIS award were available to the CAS Panel, though meanwhile these decision limits had been declared deprived of decisive legal value by the NADA v. Sinkewitz Panel. The assessment in the WADA v. Lallukka award thus addresses the validation of the re-calculated decision limits and removes the reservations raised in the Veerpalu v. FIS matter with respect to their reliability. Simultaneously, however, the Panel adhered to the perception of NADA v. Sinkewitz that these decision limits “merely constitute figures upon which reliance may be placed by means of evidence” and thus should not be treated as rules delimiting the scope of the prohibition, but only as evidence adduced by WADA to the effect that the Athlete’s values in the Sample were such as to justify the conclusion that an anti-doping rule violation occurred.16 Symptomatically, while confirming in line with the NADA v. Sinkewitz award that the decision limits have no legal value, the panel in WADA v. Lallukka nevertheless placed weight on the fact that the Athlete’s ratios were significantly higher than these same decision limits and thus no borderline case, and imposed a burden of proof on the Athlete to show that the decision limits create false positive findings in application of the provision in the WADC (or equivalent in the Finnish Anti-Doping Regulations) that relates to departures from regulatory provisions, thus from legal rules within the WADC regime.17

The series of awards that led to the WADA v. Lallukka reasoning raises a number of interesting questions related to the hGH test and the approach to expert evidence and analytical science in CAS proceedings. It shows, in particular, how legal hearing panels struggle to assign a clear legal status to increasingly complex scientific tools, which is reflected both in a fluctuating depth of judicial review and in hesitations on the burdens and standards of proof. This article examines these issues through the prism of the new presumption of scientific validity introduced in the 2015 WADC (Article 3.2.1), without delving too deeply into those intricacies of the hGH CAS award “trilogy” related specifically to human Growth Hormone.


WADC 2015: A Door Open to Judicial Review of Anti-Doping Science

Under the 2009 WADC, there was no settled CAS practice regarding the extent to which panels should accept to review challenges directed by Athletes against the reliability of the analytical science used to support an Adverse Analytical Finding. The CAS panels’ propensity to examine such challenges appeared dependent on prior verifications conducted under the supervision of WADA. In particular, CAS panels were more reluctant to reassess topics that had already been reviewed during the accreditation process or that were covered by a WADA Technical Document.18 Thus, factors that led the CAS Panel in Veerpalu v. FIS to look into the reliability of the decision limits included the absence of evidence of peer-reviewed publication or independent review, as well as the fact that the determination on the decision limits had not been an integral part of the laboratory accreditation for the test, as opposed to the design of the analytical method itself.19

The revised 2015 WADC, by contrast, explicitly acknowledges the possibility for Athletes to question the reliability of analytical tools in anti-doping science. Article 3.2.1 of the WADC reads as follows:

Analytical methods or decision limits approved by WADA after consultation within the relevant scientific community and which have been the subject of peer review are presumed to be scientifically valid. Any Athlete or other Person seeking to rebut this presumption of scientific validity shall, as a condition precedent to any such challenge, first notify WADA of the challenge and the basis of the challenge. CAS on its own initiative may also inform WADA of any such challenge. At WADA’s request, the CAS panel shall appoint an appropriate scientific expert to assist the panel in its evaluation of the challenge. Within 10 days of WADA’s receipt of such notice, and WADA’s receipt of the CAS file, WADA shall also have the right to intervene as a party, appear amicus curiae or otherwise provide evidence in such proceeding.”

The new provision thus seeks both to clarify the evidentiary regime applicable to the validity of analytical tools in anti-doping science, and to provide procedural guidance in case of challenges brought against this validity. Even though its significance may be somewhat hidden behind the complexity of its wording, the provision covers two aspects that can prove decisive for the outcome of a doping case and are analysed below.20

A Presumption of Scientific Validity of Analytical Tools

The new provision clarifies the burden of proof when it comes to “analytical methods” or “decision limits” being challenged by an Athlete. Its scope - in its wording and focus - appears definitely inspired by the hGH ‘trilogy’ of CAS awards, especially concerns that the door opened in Veerpalu v. FISmight trigger a wave of litigation, with Athletes systematically questioning the scientific foundations of the analytical findings.21 Article 3.2.1 thus introduces a novel type of ‘generic’ presumption, i.e. one that directly addresses the scientific validity of analytical tools applied in anti-doping.

Prior to the revised 2015 WADC, the only presumption in place for the laboratory analysis was Article 3.2.2 (previously Article 3.2.1 in the 2009 version). Under this provision, WADA-accredited (or approved) laboratories are presumed to have conducted Sample analysis in compliance with applicable procedures, in the particular matter (i.e. primarily the International Standard for Laboratories and related Technical Documents). The Athlete has to establish that a departure from these procedures occurred that could reasonably have caused the Adverse Analytical Finding. No similar presumption existed for the validity of the scientific foundations underlying those very procedures. Since the reliability of the analytical tools used is a component of the anti-doping rule violation, which is for the Anti-Doping Organisations to prove (general rule of Article 3.1 of the WADC), CAS panels were thus – declaredly at least – placing the burden on the Anti-Doping Organisation to establish such reliability to their comfortable satisfaction.22

In practice, however, the hGH trilogy shows that CAS panels undertake a true ‘back-and-forth’ between the parties when it comes to evidentiary duties, making the ultimate legal burden of proof – and related standard of proof – difficult to discern. Thus, the CAS Panel in Veerpalu v. FIS was adamant in its statement of principle that the burden is on the Anti-Doping Organisation to establish the reliability of the analytical tools to its comfortable satisfaction, but when turning to the actual assessment of the matter nevertheless implied that the Athlete had a certain burden to establish flaws in the reliability of the test.23 The same hesitations are apparent in the reasoning of the WADA v. Lallukka award, which shows the difficulty of drawing a clear line in practice between those issues that pertain to the scientific validity of the tools on the one hand, and those that pertain to procedural flaws in the application of these same tools, on the other hand.24

The new Article 3.2.1 creates a presumption that, in effect, transforms the evidentiary effort required from the Anti-Doping Organisation from a substantive one (‘are the analytical tools used scientifically valid?’), to a formal or procedural one (‘through what process were the analytical tools approved?’). The Anti-Doping Organisation is nevertheless still required to establish the factual prerequisites forming the basis for the presumption, in particular “consultation within the relevant scientific community” and “peer review”. Though Article 3.2.1 explicitly places the burden of proof on the Athlete to rebut the presumption of scientific validity, delimiting the exact scope of the issues that belong to the basis of the presumption (thus for the Anti-Doping Organisation to establish), as opposed to its rebuttal (for the Athlete to establish), may prove an arduous task for CAS panels. Hence, the interplay between the evidentiary duties on the side of the Anti-Doping Organisations and the Athletes, respectively, could well become a subject for debate before CAS in the first cases applying the provision.

The prerequisites for the presumption to enter into play, though intuitively convincing, are not entirely straightforward to assess. In WADA v. Lallukka, the additional scientific studies commissioned by WADA upon the Veerpalu v. FIS award were conducted at two universities in different countries (Canada and France). The panel insisted that the resulting “Joint Publication Paper” was “the fruit of a collaborative effort by two independent teams of experts”, and “that the study is based on a considerable and large dataset, which has been peer-reviewed and accepted for publication”.25 Under the new Article 3.2.1, CAS panels will have to provide clarification on the different components of this broadly phrased statement. In particular, it is not clear whether publication ought automatically to be considered to fulfill also the component of ‘consultation of the relevant scientific community’, which would appear a separate, cumulative, requirement per the language of Article 3.2.1. CAS panels may also be called to circumscribe the ‘relevant’ scientific community, as well as to decide whether ‘consultation’ supposes ‘support’ by this community, and what level of support ought to be regarded as sufficient to trigger a shift of the burden of proof onto the Athlete. Of note, publication in a peer-reviewed journal is a sign that the paper meets certain expectations of scientific thoroughness, but not necessarily that the contents or conclusions of the publication are not controversial within the scientific community.26

Finally, due to the mere elapse of time, advances in anti-doping science may lead to a WADA approval that was initially irreproachable becoming obsolete, so that one may wonder whether the time factor should not gradually diminish the strength of the basis for the presumption itself. In WADA v. Lallukka, the studies presented had just been completed. They had been designed and conducted specifically with a view to answering the issues raised before the CAS in prior cases, so that any argument related to a lack of relevance or to a subsequent evolution in scientific knowledge would have appeared rather far-fetched. In addition, the Athlete openly announced in the proceedings that he lacked the financial resources to substantiate the claim that the decision limits were still unreliable.27 The CAS Panel in WADA v. Lallukka was thus able to limit its assessment mostly to verifying whether the concerns expressed in the Veerpalu v. FIS award had apparently been answered through the new studies. It is hardly imaginable that such straightforward circumstances will always be realised in future cases. Here again, CAS panels will have to determine whether the studies produced in support of the approval were sufficient to trigger the presumption at the time of the approval, or whether they still are at the time of the CAS proceedings. In some situations, CAS panels may be faced with the difficult task of reconciling conflicting expert opinions on the scientific value of a study, or on its relevance and implications for the issues in dispute.

This makes the procedural instructions contained in Article 3.2.1 of great practical interest, and possibly of decisive value for the fate of future challenges against analytical tools in anti-doping.

Procedure for Challenging the Validity of Analytical Tools

A distinctive feature of Article 3.2.1, compared to the other ‘presumptions’ in Article 3.2 of the WADC, is that it includes strict instructions on the procedure to follow for bringing a challenge against the validity of an analytical method or decision limits, which can be summarised as follows:

  1. mandatory notification of the challenge to WADA;
  2. right of WADA to require the appointment of an expert;
  3. right of WADA to participate in the CAS proceedings.

The rationale of these instructions is easily reconstructed: the type of challenge contemplated is directed against the validity of certain aspects of anti-doping science as such and will by nature have effects beyond the facts of the particular matter. The new provision thus seeks to centralise these challenges and to guarantee an involvement of WADA, thereby reducing the risk of conflicting decisions and protecting the individual laboratory that performed the analysis at stake from being ‘dragged’ into cumbersome litigation.

In spite of the understandable attempt in Article 3.2.1 to preempt uncertainties and procedural objections, many situations will still require clarification in future cases.28 Thus, the provision only addresses challenges brought during CAS proceedings and appears modelled on the most straightforward hypothesis, namely an Athlete found to have committed an anti-doping rule violation by an Anti-Doping Organisation during the initial hearing process, who thereupon files an appeal before CAS and brings the challenge of the analytical science for the first time in the CAS proceedings. The hGH trilogy, however, shows that the procedural settings may well depart from this standard hypothesis. First, in all three hGH cases, the validity of the analytical science was already a key issue in the initial proceedings. Second, the Athlete only appeared in the position of an appellant in the CAS proceedings in the first Veerpalu v. FIS matter. In the two subsequent cases, the Athletes were respondents in the CAS proceedings, since they had been freed of a finding of an anti-doping rule violation by the initial hearing panels, and the case was brought before CAS by the German National Anti-Doping Agency (in NADA v. Sinkewitz), or WADA itself (in WADA v. Lallukka). These procedural settings will require procedural adjustments that do not immediately flow from Article 3.2.1 of the WADC.

The procedural instructions in Article 3.2.1 place the responsibility on the Athlete to notify WADA of a challenge, but the provision does not specify any consequences in case such notification does not take place. It is hardly imaginable that failure to notify WADA could result in a successful procedural objection against the admissibility of the appeal, or other impediment to the CAS proceedings. It would seem particularly difficult to justify such a procedural duty on an Athlete who has been freed of all charges and is facing an appeal before CAS as a respondent against the initial decision, at the initiative of an Anti-Doping Organisation. Transposed to this situation, Article 3.2.1 (“as a condition precedent to”) would have to be interpreted in such way that the Athlete ought to notify WADA within the twenty-day time limit for filing his or her answer brief under the CAS Code (Article R55). This would amount to no less than an obligation to announce the core of one’s legal defense to an entity non-party to the arbitration, a party with which the Athlete has no direct institutional or contractual link. It is more likely that in these cases, WADA would receive communication of the existence of a challenge through the Anti-Doping Organisation party to the case, or possibly through the CAS panel as Article 3.2.1 allows for. Of note, the CAS Code does not explicitly authorise CAS panels to spontaneously contact non-parties to the arbitration about a pending matter: requests for intervention or joinders may only occur upon initiative of the third party or upon request of one of the parties to the arbitration, and provided the third party is bound by the arbitration agreement (Articles R41.2-R41.3 of the CAS Code).

More generally, Article 3.2.1 will need to be reconciled with various other provisions of the CAS Code. Thus, the CAS Code leaves it to the CAS panel to determine the procedural status of third parties that wish to intervene or otherwise participate in the proceedings (Article R41 of the CAS Code), whereas Article 3.2.1 appears to give WADA the right to choose its position in the proceedings. Moreover, the decision on the need for a tribunal-appointed expert is at the discretion of the CAS panel (“it it deems it appropriate”, Article R44.3 of the CAS Code), while Article 3.2.1 seems to contemplate a case of mandatory appointment by the CAS panel provided WADA so requests. The question therefore arises whether the same right to request the appointment of an expert would belong to the Athlete, as a matter of equality of arms in the proceedings. In WADA v. Lallukka, the lack of resources prevented the Athlete from seeking expert advice and many Athlete may indeed feel deterred from making use of the possibility of challenge offered by Article 3.2.1, in spite of the legal aid that can be requested from CAS.29 The new provision could thus be interpreted by CAS panels as an incentive to make more frequent use of the possibility available to them to appoint an expert to assist them on scientific issues, thereby indirectly compensating any imbalance in the parties’ financial capacities, which could be taken into account in the allocation of costs for the expert (Article R44.3 of the CAS Code). Finally, a question not explicitly addressed in Article 3.2.1 of the WADC is the right for the Athlete - who bears the burden to rebut the presumption of scientific validity - to receive access to relevant scientific documentation that may be within the control of the Anti-Doping Organisation or of WADA only. CAS panel have used the Swiss law instrument of ‘Beweisnotstand’ (evidence necessity) in other contexts, to recognise that in certain circumstances Anti-Doping Organisations may have a procedural duty to contribute to the fact-finding process when the burden of proof is on the Athlete.30 Article R44.3 of the CAS Code explicitly gives CAS panels the authority to order a party to produce documents in its possession or under its control, provided such documents are relevant to the outcome of the case.31



Complexity is growing in anti-doping science, especially when it comes to tackling substances that can be either of exogenous or of endogenous origin. The human Growth Hormone CAS award trilogy demonstrates that legal circles, especially CAS arbitrators, will not be able to simply turn their back on the evidentiary issues going ahead with this complexity.

The new Article 3.2.1 will no doubt prompt debate in future CAS proceedings, but the provision undoubtedly has the merits of putting the importance of scientific evidence under the spotlight, as well as the difficulties of reconciling smooth dispute resolution on the one hand, and a thorough assessment of scientifically complex cases on the other.

Compared to the situation under the 2009 WADC that culminated in the WADA v. Lallukka award, CAS panels now have an explicit regulatory basis in the 2015 WADC to seek guidance from, but will also have to confront the legal and practical challenges that the new provision creates. If CAS panels wish to adequately face these challenges, they will need to fully exploit the possibilities that the CAS Code offers to them in terms of evidentiary proceedings and not shy away from delving into difficult scientific topics.


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Marjolaine Viret

Marjolaine Viret

Dr Marjolaine Viret is an attorney admitted to the Geneva bar (Switzerland) who specialises in sports and life sciences. Her interests focus on interdisciplinary approaches as a way of designing effective solutions in the field of anti-doping and other science-based domains. Her book “Evidence in Anti-Doping at the Intersection of Science & Law” was published through T.M.C Asser Press / Springer in late 2015.

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