As Serena Williams protests what she describes as excessive drug-testing, more scrutiny has emerged of her relationship with anti-doping rules.

On Tuesday, via Twitter, Williams called attention to the latest drug test she received from anti-doping authorities. In the 23-time Grand Slam champion's eyes, the focus on her has been excessive to the point of "discrimination":

...and it’s that time of the day to get “randomly” drug tested and only test Serena. Out of all the players it’s been proven I’m the one getting tested the most. Discrimination? I think so. At least I’ll be keeping the sport clean #StayPositive — Serena Williams (@serenawilliams) July 25, 2018

But I’m ready to do whatever it takes to have a clean sport so bring it on. I’m excited. — Serena Williams (@serenawilliams) July 25, 2018

It's not the first time Williams and the anti-doping rules have been in the news.

In 2016, Williams was revealed to have received several Therapeutic Use Exemptions (TUEs) from the ITF. These were made public when Russian hackers broke into the World Anti-doping Agency (WADA) database and released confidential data on 29 athletes, including TUEs for Williams and other tennis players including Venus Williams, Rafael Nadal and Petra Kvitova.

There is no suggestion that Williams has broken any rules. Within specific requirements, WADA allows athletes to use otherwise banned substances for medical purposes.

But the TUEs Williams was granted between 2014 and 2015 could indicate a need to re-examine the system, according to a leading anti-doping expert, though more information is required to assess whether any errors occurred during the process.

Key rules are sometimes not properly followed for such exemptions, says Richard McLaren, author of the McLaren Report into Russian doping at the Sochi Games and a professor at Western University.

"It's a problem area. It needs some significant tightening," McLaren said. "The way the TUE system operates, there's too much elasticity in the decision-making."

According to the documents released, Williams received five TUEs in 2014 and 2015 for the corticosteroids prednisone and prednisolone, and another TUE for a narcotic painkiller oxycodone. Corticosteroids reduce swelling and inflammation, and also heighten some physiological functions. Three other TUEs were also given for similar substances in 2010, when Williams was hospitalized and off the tour for an extended stretch because of injury complications.

Serena Williams' Therapeutic Use Exemptions (TUEs)

Date for use/Date given/Substance

*Oct 2010 - Mar 2011/23 Dec/Hydromorphone

*Dec 2010/23 Dec/Oxycodone

*Nov 27-Dec 1 2010/23 Dec/Methylprednisolone

*12-19 Mar 2014/13th Mar/Prednisone

*21-30 Mar 2014/2 Apr/Prednisone

*7-21 May 2014/8 May/Prednisone

*10-17 Nov 2014/3 Dec/Prednisone, Oxycodone

*5-10 June 2015/8 Jun/Prednisolone

Most of these TUEs were retroactive, meaning that they allow use of the banned substance prior to the granting of the TUE. In a few, the delay is just a day, while others are two weeks or more.

''That shouldn't be done," said McLaren. "You're not supposed to get retroactive TUEs unless it's an emergency. There could be some explanation, but somebody should look at it and see the explanation."

Under WADA's specifications, TUEs can be granted retroactively for 'emergency' or 'acute' conditions, though they can also be allowed under 'exceptional' circumstances or when 'fairness' requires.

But Stuart Miller, the ITF official who runs tennis' anti-doping program, indicated that this is hardly unknown in tennis.

"It's not unusual to find a retroactive TUE," he said. "In a number of cases, it's not possible for them to get a TUE prior to them needing the medication. The treatment of the athlete comes first. If the medical professional says the treatment of the athlete needs to start now, because the athlete's health is in danger, then they can apply for a retroactive TUE, as long as they meet the criteria [for TUEs].

"There are also other criteria, and one of them is an athlete doesn't have time or the committee [granting the TUE] doesn't have the opportunity to make a decision on a TUE prior to the athlete's next competition. Tennis is full of competitions. Tennis players play every single week, multiple times a week... they're not like marathon runners, who might run two marathons a year. What matters is, do they fit the criteria [for receiving a TUE]—that's all the TUE committee can assess.''

This criteria is based on the WADA International Standard for Therapeutic Use Exemptions (ISTUE), which governs all Olympic sports and requires that a TUE be for a 'significant health problem,' not have a 'significant effect on performance,' and have no 'alternative permitted medicine.' But the basis for Williams' TUE is hard to assess since most of the details are confidential.

The health problems for which Williams received the TUEs are not publicly known, nor straightforward to establish. Their dates coincided with the week before the 2014 Miami Open, the 2014 Miami Open, the 2014 Madrid Open, the 2014 Italian Open, the week before the 2014 French Open, and 2015 French Open. Williams won all those tournaments except Madrid and the 2014 French Open, along with five other titles in between those dates.

In addition, Williams had a set of TUEs during the 2014 offseason, even though oral corticosteroids are banned solely for in-competition use .

During the 2015 French Open, Williams had a TUE for the use of oral prednisolone for five days starting on June 5—the day before she won the French Open final against Lucie Safarova— which was given on June 8, following the tournament.

Asked about the circumstances of that TUE this year at Indian Wells, Williams said, "I wasn't going to play it unless I had a TUE because if you remember, I was incredibly sick. I said, I literally can't lay the final but I need a TUE to take a decongestant."

She also said she had never tested positive, and would not "cheat" in general.

Following the press conference, Williams angrily indicated she would not answer further questions on this or any other subject.

Williams' account of illness is in keeping with her visible coughing during the tournament, along with statements about falling sick following her third-round match. But at first glance, it also seems counter to her need for a corticosteroid, which is a powerful immunosuppressant, not something prescribed for a cold or virus.

Yet it is sometimes prescribed to reduce severe symptoms from a viral infection, and the ITF and WADA's guidelines specifically include a category for post-infectious cough. It allows the use of an oral corticosteroid for a period of a few days, if the athlete has used an inhaled corticosteroid and found it ineffective.

But WADA's guiding documents also suggest a post-infectious cough is usually between three and eight weeks following an infection, and calls it a 'sub-acute' condition.

It has not been settled whether corticosteroids should be prescribed during infection. A 2017 study, published in the journal JAMA, found that 40 mg of prednisolone taken for five days did not generally reduce the severity or duration of respiratory tract infection symptoms.

Still, TUE rules allow consideration for any significant health problem, and Williams' application could have been for another condition which she has not publicly acknowledged. Between 2014 and 2015, she appeared repeatedly to be ill during tournaments, retiring with dizziness from a 2014 doubles match at Wimbledon, with viral illness at Wuhan in 2014 and, according to Williams, throwing up during the final of the 2015 Australian Open, which she won against Maria Sharapova.

"I was just very sick, that's all I could say, and that's all it was," Williams told the New York Times following the Australian Open. "I had a bunch of follow-up tests in the fall, to see why I was continually getting ill and dizzy and felt like I was going to faint. I'm on some new vitamins, and I've been really good ever since."

Williams responds to comments about her from Sharapova's autobiography:

Williams has recently spoken openly about other medical issues she has experienced, including surgery for childbirth complications in an interview with Vogue magazine. Williams also mentioned in the interview that she has used blood thinners daily because of her foot injury complications in 2010. While these are not considered performance-enhancing or banned under anti-doping rules, they are not recommended for use with corticosteroids, which reduce their effects.

Either way, statements by athletes are not typically used for assessing a TUE, said Miller. "If an athlete says, 'I'm sick,' that isn't a factor that will go towards the documentation," he noted.

The way TUEs are granted in tennis is sound, Miller says.

"I actually think the TUE system is very robust. It has a number of fail-safes," he said. "That's not to say that it isn't theoretically possible for someone to circumvent these rules, but they are robust."

The TUE granting process requires doctors to submit applications on behalf of the athletes they are treating, along with supporting documentation that justifies the TUE application. That is then reviewed by an independent panel of doctors who do not know the identity of the athlete, and decide whether to grant or deny the application. The decision is then entered into the WADA database, with WADA having the ability to reverse the decision.

WADA has reversed a TUE given by the ITF to Bethanie Mattek-Sands in 2013 and 2014, and Miller has previously stated that this has not been done on any other occasion.

Indeed, according to Miller, the TUEs released by hackers showed that applications for tennis players were being granted properly.

"I went through all of the TUEs that were leaked, and there was nothing that suggested the system had been circumvented," said Miller. "There were permissions to use substances that were commonly applied for, common medical conditions.

"Athletes are just members of the public to the extent they get common conditions [and] need a medication to return them to a normal state of health. That's what the TUE system is for. It doesn't give them performance enhancement, it's there to return them to a state of normal health."

But this line between normal health and performance enhancement has become increasingly blurred. The TUEs released in 2016 also included those of British cyclists Chris Froome and Bradley Wiggins. It was confirmed that Froome had received a TUE for prednisolone during 2014, described as being for a chest infection, while Wiggins received three in 2011, 2012 and 2013 for triamcinolone, a slightly more powerful corticosteroid. Subsequently, the Daily Mail revealed that Wiggins got a package before a 2011 race, allegedly also containing triamcolone, but which Wiggins's Team Sky said was the decongestant Fluimucil, which Wiggins had taken for pollen allergies.

It eventually prompted a British parliamentary inquiry, which concluded a few months ago that Wiggins injected triamcinolone not for "medical need" but to "improve his power to weigh ratio." This led the committee to say that Team Sky had crossed an "ethical line," and showed cycling's TUE system was "open to abuse." Wiggins and Team Sky have denied any improper use.

While the performance effects of corticosteroids are still more anecdotal than established, cyclist David Millar has admitted to taking them and said they can have a noticeable effect on an athlete's physique in three days."It's catabolic so it's eating into you," he told The Guardian.

These cases and others have brought renewed attention to potential problems with TUEs. Asked if such awareness would have any effect on the way TUE applications are assessed going forward, Miller said, "Each case has to stand on its own merits. And in the same way, the independent TUE committee for the tennis anti-doping program would have no knowledge of any other TUEs in any other sport.

"They should and they do, as far as I'm concerned, make a decision about each TUE based, solely, on the information for the TUE. We furnish them with other TUEs [anonymous] for the player concerned."

The broader concerns expressed by the British parliamentary committee are not part of the decision making, Miller added.

"I'm not sure if there's enough information on a TUE application to make a judgment on a set of ethical standards," he said. "Those aren't the criteria by which they are assessed—they are assessed by a set of rules."

McLaren agreed that the TUE system is not equipped to make ethical assessments, but said that any lessons from previous cases should be taken into account.

"Yeah, absolutely. We all learn," he said. "They should go back and say did that happen, and what do we do to make sure... that it doesn't happen again. And [they] should be required to do so by WADA, but WADA these days has got so much on its regulatory plate. TUEs are a small part of a more complex anti-doping set of issues."

But hacks are also not the way to bring such issues to light, he added.

"The foundation is built on illegal activity," said McLaren. "I'm quite suspicious when I see hacking... I wonder, what did they also see and not reveal. It has a context.

''I suspect that in all these cases, there is a lot more background than is in the public domain. I know that from my own work. I was amazed at some of the things we uncovered in Major League Baseball, in the TUE area and elsewhere. Now they've changed a lot today, to their credit. You need [to] have an independent audit from time to time. Not to check the athletes necessarily, but to check the processes."

A few weeks ago, Williams and the anti-doping rules were back in the news when a Deadspin story said Williams had phoned WTA CEO Steve Simon to complain she was being targeted for testing, getting referred to US Anti-Doping Agency (USADA) chief Travis Tygart. The complaint followed a visit from an USADA officer to Williams' home. Williams discussed this further during her pre-tournament press conference at Wimbledon, adding that the officer had not come within the one-hour 'whereabouts window' during which top players are required to be at their stated location for potential testing. All players can be tested at other times, though they are not required to specify their location.

"For some reason they showed up in the morning, which they are allowed to do," said Williams, also confirming that no sample was collected. "If I'm not there, then they just leave. For whatever reason, they didn't leave. They said, I can come back."

Williams said she was "totally not in the area because my hour is actually a long time from now," and had a conversation with Tygart. Williams said she asked why she had been tested five times this season, which is more than other higher-ranked players.

"I said, I'm okay with that, as long as everyone is being treated equally," she said.

A couple of weeks before, in France, Williams' Twitter account had also said she had two tests that week itself:

And...... just like that anti doping is here ....again... second time this week. proud to participate to keep the sport clean. Even if they do test me at my current ranking of 454 in the world. Two times every week #BeingSerena — Serena Williams (@serenawilliams) May 21, 2018

Tennis players are subject to testing both by the ITF and their national anti-doping agency, along with national anti-doping agencies in the countries where they are competing. The organizations do not publish collective data about the amount of testing between them.

Neither the USADA or the ITF has made any suggestion that Williams is being targeted—top players tend to get tested more often, and those who play a lot of tournaments also tend to have more in-competition tests. Still, the tennis anti-doping program does consciously use target testing, where players can be specifically chosen for testing based on other information.

"[It] wouldn't be doing its job if it didn't use information to maximize the effectiveness of its program," said Miller.

Williams, who dropped off the rankings while away the tour during pregnancy, childbirth and recovery in 2017 and 2018, also appeared to question her inclusion in the ITF's whereabouts program, which is usually restricted to the Top 50 for singles players.

Including Williams was justified, suggested Miller, saying, "Among the criteria for selection is likelihood of winning competitions."

It's not apparent whether these answers would satisfy Williams. But she seems to be demanding more explanations from anti-doping authorities than they have been demanding from her—or themselves.

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