Why do so many elite cyclists have asthma?

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In the wake of the Simon Yates adverse analytical finding for the anti-asthma medication Terbutaline, CyclingTips has sought to answer a question many are asking: just why do so many pro cyclists have asthma? Given that said cyclists are amongst the fittest athletes on the planet, many are arguing on social media that there is a clear and troubling contradiction between this high physical condition and a breathing problem.

CyclingTips spoke to long time Cycling Ireland doctor Conor McGrane, a physician and cyclist known for his strong anti-doping stance. He’s been outspoken against the use of performance enhancing substances, yet he downplays the notion that inhalers could equate to cheating.

McGrane explains that viewpoint in the interview below, explaining the factors behind asthma and addressing the effects of the medicine used to treat the condition. He also gives his thoughts on the Yates situation, on the substance in question, and what should happen next.
This interview has been run as a straight transcript in order to present McGrane’s responses in the clearest manner possible.

CyclingTips: First off, with regards to the Simon Yates positive, a lot of people are asking ‘why do elite athletes have this asthma?’ The condition appears to be quite prevalent…

Conor McGrane: It is. Asthma affects between five and 20% of the population. With elite athletes, the incidences are higher.

There are a few thoughts about the reasons for this. Sometimes it is because people with asthma drift towards certain sports. There is a thinking that they drift towards swimming because there is very humid air [in swimming pool centres ed.], which seems to helps asthma, and towards cycling because it is a more progressive sport [note: favours progressive efforts rather than sharp, sudden ones – ed.].

Also, because elite athletes are pushing themselves to the limits, they tend to use lung capacities that normal people never use. And they would also be affected by smaller flare-ups of asthma. In other words, mild variances of it would cause a more serious effect on them.

CT: Is that because the regular person isn’t using their lungs to the same extent?

CMG: That is exactly it. You or I could get a very mild case of asthma and we probably wouldn’t notice it. But if you are going up Ventoux at maximum capacity, it is going to hold you back significantly and drop your condition by three, four, five, six, 10%.

So it is more common. That has been documented in numerous studies. And most athletes will have had it proven via lung function testing.


What aggravates the condition?

CT: Let’s consider the causes and possible reasons. Is it true that exercise-induced asthma is caused by exercising in different climatic conditions?

CMG: Yes, it is typically caused by cold, dry air, and also by allergens such as pollen and house dust mite. House dust mite is quite common, particularly when you are changing hotels all the time. You go somewhere with a mattress that hasn’t been changed in a while, and that can cause the issue.

I’m sure you know it yourself [as a journalist – ed.] Staying in hotels on races, you get some good ones and some very bad ones. So that could set it off. Also, different pollens from different plants in different areas. And going from a very warm climate to a very cold climate and vice versa can set it off.

CT: Given the nature of cycling, racing on the flat and in the high mountains in all sorts of different weather conditions, that would seem to be a perfect storm for asthma…

CMG: Yes. The riders are moving to different places and also there are regular changes in altitude. If you actually wanted to have a combination of things that would set off asthma, you would pick cycling. Especially stage races.

CT: If we accept that it is a known issue with cyclists, do you have an estimate about how many out of the riders you have dealt with need an inhaler?

CMG: About 40%, although that number is just off the top of my head.

CT: So in those cases, would the medication all have been justified beforehand by lung function tests?

CMG: Yes, it would. Some of them would have very mild versions, maybe one or two flares and never get them again. Maybe about 20% would need regular medication. But there are strong guidelines.

In Europe, there is the GOLD guidelines and the British Thoracic Society guidelines. They both recommend using preventative inhalers at a fairly early stage, which would usually be inhaled corticosteroids, at low doses.


Salbutamol, Terabutaline and the reason for their use

Inhalers such as Salbutamol and Terabutaline are Beta-2 Agonists. This refers to the type of medication they are, but there is an important difference: Salbutamol doesn’t need a therapeutic use exemption [TUE], although the permitted maximum level of the substance is 1600 micrograms over 24 hours.

In contrast, Terabutaline does. When Simon Yates was tested during Paris-Nice in March, he marked on the doping control form that he was using the substance. However the Orica-GreenEdge team doctor had apparently forgotten to apply for a TUE and because of this, Yates has ended up in hot water.

McGrane considers the differing positions on the two drugs and whether this is justified.

CT: Is it accurate to say that Salbutamol doesn’t need a TUE once it is below a certain threshold level?

CMG: There are two medications that are used as immediate relief. Salbutamol and Terbutaline. Salbutamol doesn’t need a TUE as long as you don’t exceed a certain amount. And, to be honest, you can’t go near that amount using an inhaler, unless you are taking 20 to 40 puffs [a day]. You just can’t.

The issue was that there was a feeling that some athletes were injecting it to try to get an anabolic effect. So that is why the limit is there.

Terbutaline is essentially the alternative to Salbutamol. If somebody doesn’t benefit from Salbutamol, they would usually try Terbutaline. It also comes in a version called the turbohaler, which is easier to use. It is basically a different delivery device to a standard dose inhaler, which is what people would use with Ventolin [Salbutamol ed.].

Terbutaline comes as that but also comes as a turbohaler, which delivers it as a dry powder so you don’t have be as coordinated when you are using it. Some people just can’t inhale it properly.

CT: We have heard suggestions that Simon Yates had a bad asthma attack recently. According to the journalist Matt Slater, Orica-GreenEdge has said that it was the first time for him to use Terbutaline.

Could those two be related? In other words, could that attack have prompted a change in medication?

CMG: It could have. To be honest, sometimes people who have had a bad asthma attack and were not responding to Salbutamol would try that instead. So it is an entirely justified medication.

CT: So what are your thoughts on this situation?

CMG: I have two thoughts on it. One is that I feel that this medication shouldn’t need a TUE in the first place. It is the same as Salbutamol, to all intents and purposes.

Secondly, I feel that if it did need a TUE and it wasn’t submitted, and he has a genuine documented asthma, then it is a very unfortunate paperwork error.

I have looked into this, researching it last night, and I can’t see any use for Terbutaline as a performance boosting drug, other than for people with asthma. If you have asthma it will improve things, but if you don’t have asthma that it won’t have any effect on you.

CT: However on that point, somebody tweeted out a link today to a scientific paper which appeared to show a boosting effect in terms of short-term power. Have you seen that research?

CMG: I didn’t see that but, to be honest, there are small studies that suggest everything. You can find a study to prove what you want if you pick one in isolation.

A lot of these studies are, for example, on animals rather than humans. A lot of the other studies are on very small cohorts, maybe five or ten athletes with very mixed results.

And, the thing is that if you have asthma and you take Terbutaline, it will improve repeated efforts. But that’s because it is just bringing you back to normal.

The point of asthma drugs is not to improve your performance as such, it is to bring you back to normal from sub-normal.

Simon Yates (l) racing on the track with Owain Doull. Doull vouched for him via Twitter after the news of his case emerged.
Simon Yates (l) racing on the track with Owain Doull. Doull vouched for him via Twitter after the news of his case emerged.

“I feel genuinely sorry for Simon Yates…I can’t see any sinister connotations to this at all”

CT: Do you believe if somebody doesn’t have asthma but takes an inhaler, that there is a boost?

CMG: No. It might simply give you palpitations.

CT: So you feel the only way that people who don’t have asthma might be getting a boost is if they are injecting these substances rather than inhaling them?

CMG: Yes.

CT: So, to finish, is there something that you would like to see changed with the rules as a result of this situation with Simon Yates?

CMG: The WADA rules are being constantly revised. We used to have to provide TUEs for Salbutamol and that was a nightmare. Various people in Ireland and the UK repeatedly lobbied WADA to remove Salbutamol from needing a TUE and eventually it was. I really feel that Terbutaline should have been removed at the same time.

In this case, I feel genuinely sorry for Simon Yates. This is not a regular doping infraction. It is not like EPO or anabolic steroids or even close. It is a drug that is used to treat asthma, and that is all it is.

I can’t see any sinister connotations at all. And you know me – I’m pretty anti-doping.

This is one of the cases I honestly can’t see any reason why they would take that, other than an asthma attack.

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