By William James

The small passages that carry air deep into the lungs are called bronchi and everyone has a reflex that protects that delicate tissue from damage. When exposed to a foreign material the muscle in the walls of the bronchi contract, narrowing the passage making it difficult for any more
of the contaminant to enter the lungs. Cells in the wall of the bronchi also secrete more mucous to help trap the contaminant and protect the bronchi.
This a normal reflex but in the two million people in Australia who have asthma the reaction is “hypersensitised”: they react severely to relatively common contaminants such as pollen, house dust and pet hair. As a result of the widespread bronchoconstriction and mucous production they find it extremely difficult to move air out of the lungs during these asthma attacks. Modern medications and reducing exposure to trigger factors controls asthma in most people and it’s not a hindrance to exercises such as cycling. But what if exercise is the trigger factor? A study of the 1988 US Olympic team demonstrated a high prevalence of Exercise-Induced Asthma (EIA) among team members. It was more commonly associated with the endurance sports but it was found among athletes participating in nearly all sports and it didn’t necessarily predict poor performance: of the 597 member team, the 67 athletes with symptoms of EIA were responsible for winning 41 medals including 15 golds and 21 silvers. Exercise-Induced Asthma (EIA) shares the same pathology as asthma: the bronchi react in the same way as when they are exposed to an allergen, only in this case, the trigger is aerobic exercise lasting for more than a few minutes. Why exercise causes the release of inflammatory substances in the bronchi is not well understood and it can occur in people who have been diagnosed with asthma, or in people who have normal lung function at other times. Unrecognised it can limit a rider’s ability to train effectively or even to take part in easy rides with friends, discouraging them from further activity, but the medal winning results of athletes with EIA should send a strong message that with proper medication and management, athletic performance does not need to suffer. It usually takes a relatively high intensity of exercise, above about 85% of maximum heart rate for more than five
minutes, for EIA to be triggered and the common symptoms are wheezing, coughing, shortness of breath, prolonged recovery time and chest tightness during or after exercise. Cyclists suffering EIA may simply slow down to try to regain control of their breathing but often the reaction is worst just after exercise stops so this can be a particularly distressing time: struggling to breathe as their friends ride away. In most cases EIA resembles “allergic” asthma in symptoms and there is often an overlap between the two pathologies. People with airways slightly. may only experience symptoms when the two occur together. So some cyclists may only notice the symptoms when riding in cold, dry air, or at times when pollens or pollution are at their worst. Modern asthma medications are extremely effective at managing the disease and, if used appropriately, have little or no side effects. The first step in effective treatment is being diagnosed. You should visit your doctor first, describe your symptoms and expect to be referred to a respiratory specialist. They should investigate all your trigger factors including exercise and work with you to prescribe a medication regime that best suits your needs. It’s important to see your doctor even if your symptoms occur infrequently. Left untreated over a long
period your airways can slowly change and become more sensitised. If, one day, you are exposed to a trigger factor you may experience an attack much worse than anything you have previously experienced and you may not have the experience and medications on hand to deal with it properly.
Once you have your medications it’s vital you use them as prescribed. Asthma medications are broken into two common groups: Preventers and Relievers. The Preventers slow the adaptation in your airways making it less likely you will get symptoms.Relievers work to reduce the symptoms
once they occur. Too many people ignore their Preventer (because they don’t have any symptoms when it’s time to take it) and rely too heavily on their Reliever. Use your Preventer effectively and you will probably not need your Reliever so much. Studies have also shown that coordinating your exercise and medication can minimise symptoms and maximise
performance. With most episodes of EIA there is a refractory phase where symptoms tend to ease after an early peak. A gentle 15-30 minute warm up followed by a 15-minute rest period, at which time medication is administered seems to control symptoms during subsequent maximal performances and this can help athletes with EIA who want to include heavy training sessions. Asthma should not affect your cycling and the fact that many Olympic athletes have asthma and still compete successfully should reinforce that asthma can be controlled. The key is awareness to the signs and symptoms and seeking the right treatment.

Exercise Induced Asthma
>Symptoms: Can vary widely but include
wheezing, chest tightness, cough and
shortness of breath.
>Occurrence: EIA affects 12-15 per cent
of the population. EIA is experienced by 90
per cent of asthmatic individuals. Eliminating
those with allergic asthma, a 3-10 per
cent incidence of EIA is seen in the general
population.
>Diagnosis: Based on medical history,
physical exam, and lung function tests.
Trigger Factors: Allergic asthma, cool
temperatures, low humidity environment,
pollution, high pollen counts, coincident
respiratory infections, poor fitness.
Chemicals used in certain sports for maintenance
can worsen EIA. Some drugs can also
trigger asthma and these include aspirin and
other nonsteroidal anti-inflammatory drugs
such as ibuprofen.