What is exercise induced asthma?

Exercise induced asthma is a type of asthma that is triggered when you do exercise. It is a long term condition that can cause symptoms like shortness of breath, tightness in your chest, and a persistent cough. When you have exercised induced asthma, you may notice these symptoms while you are exercising or after you have exercised. This usually gets better when you stop exercising and rest. You may need an inhaler to prevent and relieve exercise induced asthma. 

How common is exercise induced asthma?

According to this study, exercise induced asthma is a common condition that affects 12 to 15% of the world population, as of 2008. Around 90% of asthma patients are also affected by exercise induced asthma. 

What are the symptoms of exercise induced asthma?

Exercise induced asthma symptoms will trigger when you are doing certain forms of exercise. Most symptoms get better when you stop and rest. Exercise induced asthma can cause symptoms such as:

• persistent coughing
• a tightness in your chest
• wheezing, which is a squeaky sound when you breathe
• shortness of breath
• extreme tiredness

These symptoms happen because asthma causes your airways to become narrow and sensitive. This means that you begin to cough and find it harder to breathe, as you cannot get enough air in and out of your lungs.

Symptoms usually start while you are exercising and can get more severe the more you exercise. You may still have symptoms for a few minutes up to 30 minutes after you stop exercising. If you have asthma already, you should use your reliever inhaler. 

How do I know if I’m having an asthma attack?

When you exercise, you may feel out of breath, have a faster heartbeat, and become red in the face. This can be normal, but if you notice any symptoms listed above that are getting worse, you may be having an asthma attack. If you are having an asthma attack, you can become so breathless that you cannot speak properly.

If you have a reliever inhaler because you have been diagnosed with asthma already, you may need to take this multiple times, following your asthma action plan. You should call 999 or get to A&E straight away if you think you are having an asthma attack and do not have a reliever inhaler, or if your reliever inhaler does not relieve your symptoms

Exercise induced asthma complications

If you leave your exercise induced asthma untreated, you are more likely to have an asthma attack. This is serious and can take some time to recover from. It can also be fatal without the correct treatment. 

When any type of asthma is left untreated, it can also cause further complications. When your airways are inflamed regularly and you are not taking medication to help, your airways may become permanently inflamed and stiff, causing chronic symptoms.

When should I talk to a doctor about my exercise induced asthma?

If you think you have exercise induced asthma, you should speak to your doctor straight away. It can be dangerous to leave any type of asthma untreated.

What causes exercise induced asthma?

When you exercise, you begin to breathe faster and deeper because your body needs more oxygen. Many people begin to breathe through their mouth, meaning the air you inhale is cooler and drier than through your nose. Your airways begin to narrow and exercise induced asthma can be triggered.

You can get exercise induced asthma at any point in your life. Dry and cold air is one of the main triggers of exercise induced asthma, but it can also be triggered by other things, such as:

• high pollen count 
• pollution
• a recent illness that affected your airways and lungs, such as a cold
• exposure to certain airway irritants, such as fumes or smoke
• doing an extended period of exercise, such as long distance running or football

What increases your risk of exercise induced asthma?

You may be more likely to get exercise induced asthma if you:

• already have asthma, eczema or hayfever, or have a family history of asthma
• have been exposed to second-hand smoke as a child
• are very overweight
• had lots of lung infections during childhood or were born prematurely

According to this study, more athletes are diagnosed with exercise induced asthma than the general population.

Another study found that children who live in urban areas and are exposed to more pollutants are more likely to get exercise induced asthma. 

Why do I keep getting exercise induced asthma?

You may keep getting exercise induced asthma because something is triggering your symptoms. This could be a certain type of weather, a certain type of exercise, or an allergy or pollutant. If you suffer with asthma, exercise induced symptoms can be a sign that your asthma is not well controlled and you need to step up your preventer treatment according to your asthma action plan. 

What types of exercise trigger asthma?

Any exercise that means you are constantly active for a long time can trigger asthma. This could be sports such as football, basketball, or rugby, where your airways are narrowed for hours at a time. 

Any exercise that is high intensity can also trigger asthma symptoms, as you are working harder and breathing faster. This makes it harder to breathe properly and you will breathe in more pollutants. This could be any cardio workouts, like running.

Exercise that is done in cold and dry weather can also irritate the airways and cause exercise induced asthma. This includes sports such as ice skating, ice hockey, and snowboarding.

What types of exercise are less likely to trigger asthma?

Certain types of exercise are better if you have exercise induced asthma. This includes sports that involve shorter bursts of exercise called anaerobic exercise. This puts less pressure on your airways and can involve activities such as:

• yoga
• table tennis
• walking 
• cycling
• wrestling
• volleyball
• gymnastics

You can also do low intensity exercise, such as walking or slow cycling instead of running. Swimming in a warm, humid environment can also help. 

How is exercise induced asthma diagnosed?

Exercise induced asthma is diagnosed by a doctor. They will talk about your symptoms and what triggers your asthma. They may also perform some tests that involve breathing into a machine. Sometimes a specialist referral might be needed to do a test of your breathing whilst you exercise on a treadmill. You should never self diagnose asthma, as it’s important to rule out other conditions that can cause similar symptoms and to make sure you receive the correct treatment. 

What tests would a doctor perform?

Exercise induced asthma is usually diagnosed by a doctor taking a history, examining you and completing a few basic breathing tests called a peak flow and spirometry. They may also consider doing an exercise induced asthma test. This involves a spirometry test, where you breathe into a machine. This can check your lung function. A doctor may also monitor your oxygen levels and heart rate. You will then be asked to run or walk quickly on a treadmill. 

The same spirometry tests will be done again several times to see if your lung function has changed. Your doctor will also look at any changes to your oxygen levels and heart rate. If your doctor thinks there could be another cause for your symptoms they may order different tests like a chest x-ray. 

How do I know if I have exercise induced asthma?

The only way to know for sure if you have exercise induced asthma is by speaking to your doctor. They can do tests to diagnose your condition so you can get the correct treatment. 

How is exercise induced asthma treated?

Exercise induced asthma can be treated with asthma medications, such as inhalers. Exercise induced asthma cannot be cured, but the right asthma treatment plan can help you to prevent symptoms. You may be given an inhaler which can be taken just before you exercise, daily, or when you have symptoms. Oral medications are also sometimes needed to treat exercise induced asthma that hasn’t improved with inhaler treatments. 

Inhalers

If you only get asthma symptoms when you exercise, you will be given a reliever inhaler. This type of inhaler contains a medication called a short acting beta agonist or bronchodilator. It helps to open up the airways by relaxing the muscles. You can take it 10 to 15 minutes before you exercise to prevent symptoms for up to 4 hours. You can also take it if you get symptoms whilst exercising.

Another type of inhaler that can be used in exercise induced asthma treatment is a preventer inhaler, which contains a long acting bronchodilator. You should take this every day as instructed by your doctor to try to prevent asthma symptoms from occuring. 

There are also inhalers that act as both a preventer and reliever inhaler, such as Fostair. 

Medications

There are other medications available if you have exercise induced asthma and your symptoms are not well controlled with inhaler treatments.. 

Exercise induced asthma medications include:

• steroid tablets, which are sometimes prescribed in short courses if you have a flare up of your asthma symptoms
• theophylline, a bronchodilator which opens your airways and is taken daily
• leukotriene receptor antagonists (LTRAs) such as montelukast, which reduces inflammation in your airways

How effective are exercise induced asthma treatments?

Exercise induced asthma treatments are effective when taken correctly. If you have been given an inhaler, your doctor can show you how to use it properly to make sure it is effective. If you have a preventer inhaler and have been told to use it every day, you should take it even if your exercise induced asthma gets better.

If at any time your asthma treatment is not working, follow your asthma action plan and speak to your doctor straight away. They may need to change your medication.

How long do exercise induced asthma treatments take to work?

A reliever inhaler, which is one of the most common exercise induced asthma treatments, will take around 5 to 15 minutes to work. 

A preventer inhaler can take a few days to a week to improve your asthma symptoms. These work best when taken daily for a long time, as the medication has time to take effect in your body and keep your airways open.

What should I do if I’m having an asthma attack?

If you have already been diagnosed with asthma, you should have an asthma action plan. This will tell you what to do if you have an asthma attack. It will tell you how many puffs of your reliever inhaler to take and how often you can take it if your symptoms are not getting better. You should also sit down and try to calm your breathing.

If your symptoms do not get better and you have taken your inhaler and medications, you should call 999 or get to A&E straight away. If your asthma attack gets better after using your inhaler, you should still let your doctor know what happened. 

How to prevent exercise induced asthma

There are things you can do to help prevent exercise induced asthma, such as:

• taking your asthma medications as prescribed
• warming up properly, as this can help your body get prepared for exercise
• breathing through your nose instead of your mouth, if you can, as this warms the air
• doing exercise with a scarf around your face to warm up the air, as this will irritate your airways less
• avoiding triggers if you have allergies, such as not exercising outdoors if the pollen count is high
• avoiding exercise in any area with high pollution, such as a road with lots of traffic
• exercising in shorter bursts, rather than one long session
• quitting smoking, as this can reduce how often and how severe your asthma symptoms are
• eating a healthy and balanced diet, as being overweight can put more strain on your body and airways
• getting regular vaccines such as the flu jab, as illnesses can trigger asthma symptoms and make them worse
• keeping warm and dry whilst exercising
• having regular check ups with your doctor to make sure your treatment plan is correct for your symptoms

sources

Asthma (2021) NHS (accessed 14 July 2022)

Exercise-Induced Asthma: Fresh Insights and an Overview (2008) PubMed (accessed 14 July 2022)

Exercise-induced bronchoconstriction: diagnosis and management (2011) PubMed (accessed 14 July 2022)

Prevalence of exercise induced bronchospasm in Kenyan school children: an urban-rural comparison (1998) PubMed (accessed 14 July 2022)