Martin Maes cut pre-infection
More on Martin Maes' Doping Ban and the TUE Rule

Martin Maes and Dr. Clark Lewis Respond to UCI Ban

Photos Enduro World Series & Clark Lewis

On June 26, EWS fans and racers the world over were shocked to hear Martin Maes had tested positive for a prohibited substance. The substance in question was Probenecid and while not considered a performance enhancing substance, it’s listed on the World Anti-Doping Agency’s “Diuretics and Masking Agents” prohibited list. The drug was prescribed to Maes by a volunteer doctor during the NZ Enduro. Maes had sustained a deep laceration to his shin that had become infected despite antibiotics. Soon after consulting the event doctors, the infected cut had become “potentially life-threatening,” probing doctors to administer Probenecid in conjunction with a higher dose of the antibiotic, Flucloxacillin.

In an effort to learn more about the situation and drug in question, I reached out to Martin Maes, the UCI and Whistler Emergency doctor, Clark Lewis. Martin, understandably upset, had little more to say on the situation and the UCI refused to comment any further. Dr. Lewis was very helpful.

Clark Lewis

Dr. Clark Lewis

Clark Lewis – Emergency Doctor with 14 Years Experience

Clark’s been riding throughout the Sea To Sky since 2003. He’s raced downhill, cross-country, and some enduro but now prefers to rip everyone’s legs off during full day excursions. He was also instrumental in the development of Chromag’s new Doctahawk frame. He’s been an emergency doctor in the area since 2005 and started working in Whistler on a part-time basis in 2007, and full-time since 2013. He also accompanied Red Bull's North of Nightfall crew to the arctic as their on site medic.

It’s no secret there are a lot of riders flocking to Whistler each year and with that, Clark has seen a disproportionate amount of mountain bike trauma while working there. That experience has seen him work regularly with Probenecid, which he uses on a daily basis with patients. He had some great insights on the Maes situation.

NSMB - What is Probenecid typically used for?

Dr Clark Lewis - We've used Probenecid literally every day to prolong the metabolism of antibiotics, just as in Martin's case—it's very, very common. In Whistler there are several people every day that come in once daily for intravenous antibiotics to treat their infected shin and elbow lacerations from bike crashes. Probenecid allows the antibiotics to be given once daily instead of three times, which is much better for "outpatient" treatment.

No matter how well these lacerations are scrubbed, the infection rate is high due in part to poor tissue vascularity—likely an evolutionary remnant from caveman days, so you wouldn't bleed to death defending yourself from people and animals trying to murder you.

Could Martin have accessed more than he was prescribed by the doctor?

Probenecid is prescription only, at least in the developed parts of the world. In some places it's used to treat gout by enhancing uric acid elimination, but we treat gout differently here.

In his situation, what options would you consider Martin Maes had aside from Probenecid?

We would have given Martin the same treatment, it’s very standard.

I’ve read that it needs to be taken in high doses of between 2–5g to prevent banned substance detection (Maes was prescribed 1.5g/day). Does that sound accurate to you?

I'm not familiar with using it to mask illegal agents. We give one gram orally, once daily with the intravenous antibiotic Cefazolin.

How long does Probenecid remain in the system?

Its half-life in plasma varies with dose, but it's generally thought to be 4–8 hours for the dosing we use, making it ideal for once daily dosing (5 half-lives generally takes the plasma levels down to very low levels). However, the half-life is long enough that you'd expect to detect trace amounts many days after stopping use. A pharmacist could shed more light on details around plasma concentrations.

Is there an alternative that could have been used, or would Maes have needed to pull out and head to the hospital?

There are alternative intravenous options, like once daily Ceftriaxone, but this is broader spectrum and generally overkill. There aren’t better oral options in this scenario.

Overall, this is a real bummer for Martin. Professional athletes must be extremely careful about what they ingest, almost to the point of paranoia. It would seem prudent these days to avoid any type of supplement (they're mostly bullshit anyway), and just eat good food, drink water and coffee and beer.


Martin Maes

Martin is understandably upset by the UCI decision and probably wants it all to go away already. His responses here are short but there’s one area that keeps coming up and that’s the TUE (Therapeutic Use Exemption) filing.

The team statement notes that you and Mark Maurissen asked the medics whether Probenecid was banned but no one was able to confirm due to location. Did you consider checking once in a location with wifi access?

I followed the doctor’s advice without questioning what was prescribed because it was medically necessary to treat my wound, and nothing prescribed would aid or benefit my performance. In fact, it might have inhibited my performance. Yes, we should have researched these prescriptions more closely but in the moment, I was confident with the information I was given.

When did you take your final dose of Probenecid?

I followed the prescription per the doctor’s advice, taking the Probenecid as it was prescribed.

When was the TUE filed? Why was the TUE filed when it was?

We received the denial for the TUE on June 1st.

Would you have pulled out of the race if you knew you couldn’t take Probenecid?

Being healthy was my first priority. If I knew that I couldn’t have taken the Probenecid, I would have found alternative courses of treatment.

What are your thoughts on medics who work events having to know what is and isn’t banned?

All the medics and volunteer medics at these events are great. My doctor made the best decision for my health.

Do you think riders should be just as aware of banned substances?

If riders are taking a substance that they think might be questionable, it's up to them to do the appropriate research.

Is the suspension across disciplines?


What are your plans for the remainder of the year?

This situation was obviously not planned. I’ll be evaluating the timing and shift of my goals for the rest of the 2019 season.

Martin Maes broken hand in Finale

Martin with a broken hand in Finale in 2018.

Final Thoughts

Unfortunately it appears Maes will be the example that other athletes learn from. I reckon his peers have been hitting WADA’s Prohibited Substance list hard over the last week and possibly downloading whatever they can for later reference. While many have argued that it’s up to athletes and their teams to know what’s safe and what isn’t, I still believe medics at UCI sanctioned events should only be prescribing legal options. In Martin’s case, it was up to him and his team and it’s at similar events that aren’t under the UCI ‘brolly where competitors will need to take note in future.

An error was made by Martin and his team and they’re now paying the price with a 90-day suspension from racing. Whether we believe it's fair or not, it does appear, as other fans have speculated, that the TUE was filed later than the UCI would have preferred. I believe that it’s for this reason the UCI followed through with the penalty Maes has received, despite acknowledging the use was for valid health reasons. And while they acknowledge the use of Probenecid, they still claim other treatments were available. As Clark mentioned above, other treatments would have involved a trip to the hospital for intravenous treatment.

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+1 Mammal IslandLife Saša Stojanovic

The Wada Prohibited List is available for PDF download to your phone here:

If you open in a PDF reader and search for "Probenecid" it comes up. That search process takes about 30 seconds. 

Given the amount of preparation athletes and teams do for each season it's inexcusable that they didn't do that and have that list available to them away from cell service or at least follow up once they got back into range. It's not the volunteer medical staff that are responsible for staying legal with respect to anti-doping regulations it's the athlete's responsibility. 

Keeping in mind Richie and Jared had been caught with a Prohibited Substance in them at the EWS in 2018...downloading the Prohibited List to your phone for reference shouldn't be happening just now.

Both Richie and Martin got relatively light sanctions for their infractions of the WADA rules. That shows that the folks adjudicating their cases took into account extenuating circumstances and wanted to be lenient. That seems like reasonable outcome for this process.


+1 IslandLife

Yep, easy to access for sure. Perhaps because there wasn’t any official testing prior to last season riders and teams weren’t really considering it fully. They’re certainly aware now.

On the TUE topic. From the PDF it seems to be required to have an approval prior to testing.

> The detection in an Athlete’s Sample at all times or In-Competition, as applicable, of any quantity ofthe following substances subject to threshold limits: formoterol, salbutamol, cathine, ephedrine, methylephedrine and pseudoephedrine, in conjunction with a diuretic or masking agent, will be considered as an Adverse Analytical Finding (AAF) unless the Athlete has an approved Therapeutic Use Exemption (TUE) for that substance in addition to the one granted for the diuretic or masking agent.


+2 AJ Barlas IslandLife

Yes the TUE is meant to be applied for and approved beforehand not as a retroactive measure. That seems totally reasonable in light of how such an exemption could be abused as a way to avoid an analytical finding.

In Martin's case they could have done so once they got back to cell service range and realized that Probenecid was prohibited. It's hard to understand how a team doesn't check any medications their riders take against that list. 

Martin was racing WC DH and DH world champs in 2018 and plans to in 2019 so there is no doubt he was part of a WADA tested race last year. It's not a new thing for 2019 in terms of his requirements to stay on the right side of the WADA regulations.


+4 AJ Barlas Timer Todd Hellinga Nouseforaname

Yes, you're correct.  But sort of in Martin's defense, and to add... it mentions in another article that he and his team manager specifically asked the doctor if the probenecid was illegal.  The doctor said no, checked with another doctor and they both agreed it was fine.  Quote: "We obviously did ask and he did tell us that it was all fine. There were two doctors and they guaranteed us there was no issue about it."

But then he also says: "At the same time, we 100% trusted the doctor and when you go to the doctor most of the time you just trust him and you don't check every medicine that is prescribed to you."

And: " team manager, tried to check on the Wada list that day but there was no signal where we were so we ended up not checking, that was the huge mistake."

So, I believe he knows full well that #1. they shouldn't just trust any doctor, especially one that is not at an actual EWS event.  And #2. He knows they should have checked the list once they had access to wifi/cell range and that it was their own fuck up for not doing that.

So yes, this all could have been avoided if, once in cell range, they checked the list, found it illegal, and went back for the TUE.

It will serve as a wake up call to all riders, team managers and teams: everyone should be carrying an updated list, should check everything they are given before taking it and get a TUE immediately if needed.

It's a fairly young discipline and series and you can expect these kinds of mistakes as the EWS becomes a more professional series, but the UCI cannot bend or break it's own rules just because he's a nice guy who wasn't actually trying to cheat.  The rules are hard and fast for very, very good reasons.



In the doctor's defense: As we have seen in this interview here, most doctors are not aware of the role that probenecid can play as a masking agent. Because it is not performance enhancing, im not surprised that the doctor's in NZ considered it harmless.



This article has a response from the emergency doctor in question.

In all reality I think the final onus falls on Martin and team to check, they had two weeks between the NZ Enduro and EWS Rotorua to check and apply for a TUE. If they had of, I feel that the TUE would have been granted and this whole thing avoided.

At the end of the day this is a hard lesson, and I do feel really bad for Maes in this instance.



We posted the NZ Enduro doctor’s response here:

+1 kiwizak

Agree with the above. Having taken probenecid I think they should have immediately applied for the TUE. Waiting to get the adverse finding and then applying is the wrong way round.

Harsh lesson for all athletes and I'm sure some changes to behavior will be required.



I have no opinion on the topic at hand, but when I end up at the Whistler clinic and Clark walks in the room I feel a lot better.

Here's to hoping all of you who end up there see Clark as well.


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