The sporting population is known to have a higher incidence of asthma than the general population, and this is worse when practising winter sports. The prevalence of exercise-induced asthma can range from 20-60%, depending on the type of sport undertaken and over what period of time.
Exercise-induced asthma occurs when a person undertakes exercise, resulting in a large amount of air exchange occurring throughout the bronchial and alveolar airways. Usually, when at rest, air is humidified through the nasal passages when inhaling, but at high levels of exercise these are bypassed as most inhalation occurs through the mouth rather than through the nose, so the lower airways are responsible for humidifying the inhaled air. This increases the chance of the airways constricting and causing EIA.
Over and Under-Diagnosis of Exercise-Induced Asthma
When EIA is over-diagnosed, it is often because those who visit their doctor stating that they are suffering from a cough, wheeze, shortness of breath or other respiratory ailment related to exercise are often diagnosed and treated for exercise-induced asthma, without proper investigation or understanding of the underlying respiratory issue.
The under-diagnosis aspect is harder to detect, as it often occurs in the highly active population, but no symptoms are present, so the shortness of breath of exercise is only attributed to exercise, and not to exercise-induced asthma. Hence, EIA can only be detected once appropriate testing is undertaken and not through reporting respiratory symptoms.
Testing for Exercise-Induced Asthma
The gold standard test to correctly diagnose EIA is a eucapnic voluntary hyperpnoea (EVH) test.
This is a 60-minute clinic based test, so the main advantage is that it will not interfere with any training plans, and can also be undertaken if a person is injured or unable to exercise for whatever reason.
The first stage involves assessing baseline lung function, through what is called spirometry. All you have to do is to blow into a device that measures lung function and it will provide instant results of lung health.
The second stage of the test involves inducing EIA. A special machine attached to gas cylinders is responsible for mixing the right mixture of gases, which you will inhale and exhale at a very fast rate for six minutes. This is done using a face-mask, but whilst sitting down, so there is no physical exertion related to the test.
The third and final stage of the test continues by re-assessing the lung function test through the spirometer for 15 minutes. Here is the stage where any change in lung function is picked up and the correct diagnosis can be made.
Diagnosis and Treatment
Once the full test results are analysed, an appropriate diagnosis can be made and this is followed up by targeted treatment and advice to ensure that those who exercise do so in a healthy way, especially in relation to their airways.
The aim of such screening is to ensure that active people are undertaking exercise to promote health, whilst ensuring their airways are not being compromised through exercise-induced asthma.
The medical advice provided is intended is for educational purposes and not for self-treatment. Should you experience similar symptoms, you are advised to contact your doctor/specialist for individual specific advice.
© 2017 – VIDA Magazine – Dr Danica Spiteri