The idea of a supremely fit professional cyclist like Simon Yates having to occasionally reach for an inhaler to ward off a wheeze might seem anomalous. But asthma is surprisingly common among some elite athletes.

A handful have classic asthma, the usually allergy-triggered constriction of the bronchial tubes that tends to begin in childhood.



Much more common in sport is exercise-induced asthma, or EIA, in which rapid and heavy breathing causes the same symptoms. The effect can be exacerbated by atmospheric conditions, which means some sportspeople tend to suffer more than others.

John Dickinson from Kent University’s school of sport & exercise sciences, a world expert on asthma in sport, tested all 33 UK-based members of the British swimming squad and found 70% had some form of asthma, against a national asthma rate of about 8% to 10%. It is believed the chlorinated atmosphere of a pool could be a factor in this.



Cycling is another sport where EIA is common – Dickinson’s test on cyclists from Team Sky found a third have the condition. Rapid inhalation of cold, dry air has been identified as a trigger of EIA. Around half of elite cross-country skiers have the condition, as does Paula Radcliffe.



While EIA can occasionally bring on have very serious symptoms, sometimes athletes do not realise they have it until they are tested. The test involves them breathing a very dry air mixture for six minutes at high ventilation, with their lung function tested before and after. The asthma-induced fall in lung function can be as much as 40%.

Speaking to the Guardian in 2014, Dickinson said the condition remained a source of some debate: “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.”

It’s not unknown for professional cyclists to carry a reliever inhaler, which helps stop a wheeze as it begins, in the back pocket of a jersey. Use of salbutamol, the most common form of such bronchodilator drugs, usually taken as a blue inhaler, does not need a doctor’s therapeutic use exemption certificate within certain limits.

Terbutaline, the bronchodilator taken by Yates, is permitted by anti-doping authorities as an inhaler, but only with a certificate. Certificates are also needed for the more powerful preventer inhalers for asthma, which aim to ward off symptoms, the most common of which are steroid-based. The injection of any anti-asthma drugs is not permitted.