A study carried out by John Dickinson, head of the respiratory clinic at the University of Kent, has found that a third of Team Sky’s riders suffer from asthma to some degree. The Guardian reports how Dickinson’s research has revealed that a surprisingly large number of elite athletes have asthma across many different sports.

The national asthma rate is about 8-10 per cent. However, Dickinson found that rates were sometimes even higher in top level sport. Having also tested all 33 UK-based swimmers from the British Swimming squad, 70 per cent were found to suffer.

Crucially, the form most commonly seen is not the allergy-induced one frequently seen among children but exercise induced asthma (EIA).

Dickinson explained:

“It depends which respiratory consultant you talk to on whether you put these athletes on a spectrum of asthma, or whether you think that’s purely down to them exercising really hard in a certain environment, and if you take them out of that environment they’re fine. It’s a grey zone. But my argument is it’s a form of asthma.”

EIA involves similar symptoms – contraction of the airways – but is brought about by rapid breathing through exertion rather than allergies. Atmospheric factors will often exacerbate the condition – in particular cold air. This may be why road cyclists often suffer, although cross-country skiers appear to be affected to an even greater degree with half exhibiting the condition. It is thought that the chlorine environment in pools may also be a trigger.

Dickinson tested athletes by asking them to breathe very dry air for six minutes at high ventilation. Lung function was tested before and after and the drop seen was sometimes as high as 40 per cent.

Athletes can use common bronchio-dilating inhalers like salbutamol so long as they do not exceed a certain dose. Earlier this year, Lampre-Merida’s Giro stage winner, Diego Ulissi, tested positive after nearly twice the maximum permitted level was found in his urine. While his hearing took place last week, the verdict has been postponed until January to allow Ulissi’s legal team to compile a full statement of defence.

Dickinson says that a surprising number of cyclists carry inhalers while they ride. “Cognitively, the inhaler can give you the confidence to push yourself that little bit more. Sometimes a rider will know a climb is coming, so they take a couple of puffs.”

When he was spotted using an inhaler in this year’s Tour of Romandie, Chris Froome was quoted as saying: “I have had an inhaler since childhood. I have exercise induced asthma. It is ok. I didn't need a TUE. I don’t use (the inhaler) every time I race, normally only when I have a big effort coming up.”

In May 2008, the Court of Arbitration for Sport handed a ban to Italian sprinter Alessandro Petacchi and stripped him of results including five Giro d’Italia stage wins after he tested positive for an excessive amount of salbutamol.

In its ruling, CAS acknowledged that Petacchi, who was permitted to take the medication, had not intended to cheat, but held that he had failed to exercise “utmost caution” in exceeding the permitted dosage.