Exercise Induced Asthma
The term exercise-induced asthma refers to a form of asthma that is triggered by strenuous exercise. The person may have no other symptoms of asthma normally, but when they exercise their airways contract and the symptoms of asthma are triggered. Sports Asthma UK estimate that the condition can affect up to 50% of athletes.
There is no one singular cause that has been identified, and there may be multiple factors than contribute to the onset of the condition. The mayo clinic highlights the following factors that may increase your risk of experiencing the symptoms of exercise-induced asthma. These include being exposed to:
- Cold or dry air
- Pollution in the air
- High levels of pollen
- Chlorine when swimming in pools
- Chemicals used when resurfacing ice rinks
- Respiratory infections
- Prolonged periods of deep breathing as required by long-distance running, swimming or soccer
Symptoms and risk factors
The symptoms of exercise-induced asthma may come on during, or within a few minutes after, exercise and they can last for up to half an hour if they are not treated. These symptoms include:
- Starting to cough
- Starting to wheeze
- Experiencing shortness of breath
- Experiencing pain or tightness of the chest
- Becoming fatigued during exercise
- Under-performing athletically
- Feeling unfit despite being in good physical health
- Avoiding activity, in the case of young children
It's important to get a diagnosis if you have experienced these symptoms and think you could have exercise-induced asthma. If left untreated, symptoms can worsen. Sports Asthma UK highlight how a diagnosis for athletes is important, in particular, as it can so negatively impact on their performance and can cause serious health problems. Exercise-induced asthma has been identified as one of the causes of sudden death in sports.
There are a number of diagnostic tests that can be carried out to help identify if you have exercise-induced asthma:
This test involves taking a deep breath and exhaling as much as you can into a machine called a spirometer. The spirometer can measure:
- FEV1: Forced Exhalation Volume per second
- FVC: Forced Vital Capacity or total air breathed out
Both of these tests can identify if there is any restriction in your airway. This can be combined with an exercise challenge, so a reading can be taken before, mid and post exercise to identify when your airway is being compromised. As an alternative to exercise, you may be given other different trigger substances to inhale that recreate some of the conditions during exercise: Methacholine, Mannitol or a mixture of dry air.
The test may also be repeated after you are given an inhaled medication such as a bronchodilator, to assess if there is underlying chronic asthma and to see how effective medication is at relieving symptoms and preventing an attack.
Peak Expiratory Flow Test
A Peak Expiratory Flow (PEF) test is administered using a device called a peak flow meter. Similar to a spirometer you can breathe into this device and it will measure how fast you can exhale. You may be asked to take this home with you and track the results on a regular basis to monitor any changes with your asthma. When it's carried out regularly, it can be useful in ensuring that there is no underlying chronic asthma condition. It can also track your responsiveness to regular preventive medications and help identify any other trigger factors.
Treatment and management
There are a wide range of medications available and steps you can take to help manage exercise-induced asthma.
Your doctor may prescribe you short-acting medications to take before exercise to minimise symptoms. They can be Short-Acting Beta Agonists (SABAs), such as Ventolin or ipratropium based medications, such as Atrovent.
Long-Term Preventative Medications
When pre-exercise medications are not sufficiently bringing your condition under control, you may be prescribed other long-term preventative medications to relieve symptoms and reduce the risk of attacks. These can include corticosteroid based inhalers, such as Flixotide or Qvar; combination inhalers, such as Symbicort or Seretide; or oral medications known as Leukotriene modifiers.
Other practical tips
As well as taking your medications as required and monitoring your condition, Asthma UK offer the following tips that can help manage your asthma when exercising:
- Warm up and warm down your body before and after exercise
- Make sure you have your inhaler with you and make those around you aware of your condition
- If you experience symptoms, stop, take your medication and avoid exercising until the symptoms are relieved
- Avoid cold air as a trigger by moving your strenuous activity indoors in the winter months, or reducing the vigor of your routine
- Dress in a way that protects you from cold air; cover your chest and throat and even your mouth with a scarf.
If your symptoms worsen, or haven't improved after using a prescription inhaler you should seek emergency medical treatment.