The Human Growth Hormone test: a war of words between the World Anti-Doping Agency and the NFL Players Association

Published 27 May 2013 | Authored by: Howard Jacobs

The World Anti-Doping Agency (“WADA”) and the National Football League Players’ Association (“NFLPA”) have been in a long running debate over the application of Human Growth Hormone (“HGH”) blood testing in the National Football League (“NFL”). Howard Jacobs (The Athletes Lawyer) reviews both sides of the debate in light of the recent the Court of Arbitration for Sport decision in the Veerpalu v. FIS case.

HGH has long been banned in sport, but until fairly recently was undetectable by drug testing.  HGH remains undetectable by urine testing, although a blood test for HGH has been used in Olympic sport since 2004, albeit with relatively little success.  In 2010, the WADA published its guidelines for the HGH blood test, and these guidelines specified the procedure for sample preparation, how the test should be performed, and interpretation of the test results (including the test’s decision limits).1
The NFL and the NFLPA agreed in principle to introduce HGH testing when a new 10-year labor agreement was finalized in August 2011.  However, the NFLPA quickly retreated from that agreement in principle, citing concerns over the current blood test for HGH.  WADA and the NFLPA have engaged in a war of words over the HGH test ever since, and for much of the time WADA appeared to have the NFLPA on the defensive.  However, a recent ruling by the Court of Arbitration for Sport appears to support the concerns that have been voiced by the NFLPA for years.

As early as January 2012, the primary issues of the two sides were well established.  The NFLPA contended that (i) there had not been any peer-reviewed studies by scientists outside of WADA, (ii) no information had been provided about the population studies that WADA used to formulate the test, and (iii) the NFL did not have an outside appeals process where players could challenge the validity of the HGH test2.  WADA countered that the HGH test was scientifically valid, that the NFLPA’s objections were not based on any genuine scientific grounds, and that the NFLPA’s resistance to the HGH test must mean that there is an HGH problem in the NFL3.  That rhetoric continued until late March 2013, when the Court of Arbitration for Sport rendered its decision in Veerpalu v. FIS4 , finding that the decision limits established by WADA for the HGH test had not been scientifically proven.

One of the arguments made by Veerpalu’s lawyers, and accepted by CAS, was that the population study that had been conducted to establish the decision limits of the HGH test was inadequate.  The CAS Panel described this issue as follows:

“The issue of whether the Test’s decision limits have been correctly established by WADA is at the core of these proceedings … the Appellant submits that the decision limits are flawed or at least over inclusive. The values for Kit 1 and Kit 2 are set too low and could lead to an AAF even if the athlete did not use artificially-produced hGH, in other words, the established decision limits could produce false positive results … The Respondent rebuts, in essence, all of Appellant’s claims and has maintained throughout the proceedings that the decision limits have been correctly calculated and guarantee a 99.99% specificity of the Test. According to the Respondent, the decision limits do not lead to too many false positives but are in fact conservative that tend to result in false negatives. The decision limits had been purposefully set at high levels in order to protect clean athletes.” 5

In other words, the arguments in Veerpalu were fairly consistent with the public positions taken by the NFLPA and WADA in relation to the dispute over HGH testing in the NFL.  The CAS Panel resolved the issue as follows:

“In the Panel’s view, the Respondent has, on balance, failed to establish to the comfortable satisfaction of the Panel that the decision limits were correctly determined and that they would lead to the claimed specificity of 99.99%.  Despite the Respondent’s ample opportunities to convince the Panel on the correctness of the decision limits including in the post-Hearing brief as well as in response to the two subsequent rounds of Panel Questions, the Panel cannot exclude to its comfortable satisfaction that the decision limits are over inclusive and could lead to an excessive amount of false positive results (beyond the claimed specificity of 99.99%). Although the Panel has found that the Test itself is undoubtedly reliable (as explained in Section 5 (‘The Reliability of the Test’)), the Panel finds that the following factors prevent it from concluding that the decision limits are equally reliable: (1) The inappropriate exclusion of certain sample data from the dataset; (2) the small sample sizes; and (3) the data provided on the distribution models used.”6  

Therefore, it would appear that CAS agreed with some of the criticisms of the HGH test that have been voiced by the NFLPA for years.  Certainly that is how the NFLPA viewed the Veerpalu decision, when it released the following statement on 26 March 2013:  

“Today, an independent arbitration panel's decision found that the WADA isoform hGH test is unreliable. The suspension of an Olympic champion was overturned after findings that the hGH test administered by WADA is not scientifically verifiable. For almost two years, the NFL players have fought the NFL and certain members of Congress who have publicly referred to the players' insistence on scientific validity and fairness as “stalling” and “posturing.”  Today's decision validates the players' demand for scientific validity, full due process rights, and a transparent system.”7  

WADA, of course, saw the Veerpalu decision differently, and responded to the NFLPA press release as follows:

“I would expect the Players Association to take a stance which is extremist.  What we've got to do is get to reality and not to a position that is an extremist position … What we have to do is actually look at the decision in a very calculated, objective fashion," Howman said. "What CAS has decided is that the test is OK and what they want is for there to be a bigger population-based study in terms of the impact of it. We'll take that on board and we'll go further.”8

The reality is that both the NFLPA and WADA somewhat overstated the significance of certain elements of the Veerpalu decision.  The NFLPA was correct that CAS found that the HGH test’s decision limits were not scientifically valid, but overstated its case when it said that CAS found the HGH test itself to be unreliable.  WADA was correct in its statement that CAS found that a larger population study was needed to scientifically justify the current decision limits for the HGH test, but overstated its case when it implied that there was nothing wrong with the HGH test.  In addition, WADA’s characterization of the NFLPA’s stance on the issue as “extremist” would seem to be somewhat unjustified, since the CAS decision did agree with the NFLPA’s long-stated position that the population studies supporting the HGH test were scientifically inadequate.

What should be clear to any objective observer reviewing the fallout from the Veerpalu case is that it was a huge blow to the position WADA so publicly took against the NFLPA.  For the past two years, WADA has ridiculed the NFLPA’s criticisms of the  HGH test; has insisted that there were no problems whatsoever with the HGH test; and went so far as to suggest that the NFLPA’s resistance to the HGH test should be viewed as an admission that the NFL has an HGH problem.  In Veerpalu, the CAS validated at least some of the NFLPA’s concerns about the current use of the HGH test; and the decision effectively means that the HGH test at present is unusable.  WADA would be well advised to recognize that the interests of its stakeholders would be best served at this point by focusing on the population studies that need to be conducted before any testing body can use the existing HGH test, rather than continuing with its criticism of the NFLPA.

As between the NFL and NFLPA, the disagreement over HGH testing has stalled the implementation of other agreed changes to the NFL’s drug-testing policy, including the agreement to use independent, third-party arbitrators in appeals.  Now that the decision limits of the HGH test fall to be reviewed, thus rendering the HGH test (at least temporarily) inoperative, it is time for those other agreed changes to be implemented, for the benefit of both the league and the players.



2 CAS 2011/A/2566
6 Ibid
7 See
8 See

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About the Author

Howard Jacobs

Howard Jacobs

Howard Jacobs is lawyer in the Los Angeles suburb of Westlake Village, California. Mr. Jacobs has been identified by various newspapers as one of the leading sports lawyers in the United States, and was profiled by USA Today in a feature article titled “Athletes accused of cheating find perfect advocate.”

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Comments (1)

  • DrBenKoh

    28 May 2013 at 06:54 | #

    It would appear that both sides may have muddled the idea of validity and reliability in parts of their statements. Both constructs are related but fundamentally different.

    Validity refers to how true is something you say is true. In other words, if a HGH test says it is positive, how true is it that there was an abnormal HGH level/ratio. It deals with "specificity".

    Reliability refers to how consistent the test is. In other words, if the test is repeated 100 times, how many times will the HGH test bring up a positive result in a person that did indeed have an abnormal high HGH level/ratio. It deals with "sensitivity".

    In general, a highly specific test tends to be low in sensitivity and the reverse is also true. If you have a very strict criteria (highly specific) then your pick up rate (sensitivity) will be low.

    Imagine that you have a very strict criteria for picking up only Green T-shirts. A T-shirt that is slightly more Yellow or slightly more Blue (although within the spectrum of Green; outliers) will be rejected (low sensitivity), but whatever you pick up will truly and undisputedly be Green (high specificity).

    One wonders, if the specificity is indeed 99.99% as WADA claims, then it will likely have a very low sensitivity. This will likely to be borne out in larger sample sizes in a well-controlled experimental condition.

    In addition, the stated comments also supports the above assertion: "...According to the Respondent, the decision limits do not lead to too many false positives but are in fact conservative that tend to result in false negatives..." at [199]

    A high false negative would mean a low sensitivity (some T-shirts deemed Green may not be picked up).

    This brings the question of whether the test should be done in the first place.

    In my opinion, there is a valid argument for the NFLPA to question the validity (specificity) of the test in athletes. From the athletes' perspective, reliability is not important for them per se and is more a WADA concern "of catching the cheats".

    Even if the stability of the ratio that is claimed is true, is it true for patients with pathological conditions of HGH, in healthy subjects but non-elite/ non-athletes only, or for all humans? Because of strict liability, most validation tests are conducted on non-elite/non-athletes or extrapolating data from patient with pathologies. Can these results still be valid in elite athletes?

    If as indicated (footnote 96 at [145]) that even with a small sample size, exercise does influence the ratio of 22 kDa/pitGH ratio then a much larger sample size needs to be established to determine how large a fluctuation of the ratio exists in a variety of: exercise conditions (endurance/resistance training; various duration) and individuals (cross-cultural, both gender, age groups).

    I think it is also appropriate to have the stability of the ratio criteria (rather than absolute values) using Kit 1 and Kit 2 be tested by an independent laboratory (not nominated by WADA to ensure no conflict of interest; at [161]). This can potentially be done under confidentiality agreements so that the details of the test are kept proprietary and only reporting to the NFLPA the end results of sensitivity/specificity.

    I think that reliance on scientific instruments demand that the transparency of the scientific process and the scientific tradition of falsifying of theories be adhered to. While WADA's concern of some athletes beating the system are noted, any policy should not be at the expense on all athletes.


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