Asthma triggered by exercise

People with asthma often have symptoms when they are physically active, especially if the air is cold and dry, or they are unfit. For some people, it is the only time they experience asthma symptoms. This is called exercise-induced asthma (EIA).

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If you experience any of the following symptoms during physical activity or your peak flow drops 20% after exercise, your asthma may be exercise induced. You should see your doctor if you have:

• tight feeling in the chest
• wheezy (noisy breathing)
• breathlessness
• coughing.

There are 2 theories about the cause of exercise-induced asthma:

1. Water-loss theory. Some researchers believe that the cool air you breathe in when you exercise dries the lining of your airways. This triggers your airways to spasm and become tight.
2. Heat-exchange theory. Another theory is that increased breathing during activity cools your airways. When activity stops, the blood vessels dilate to heat the lining of your airways. The airways narrow and cause shortness of breath and wheezing.

Don't let EIA slow you down. Have fun and stay active. We all know that physical activity is good for us. This is particularly the case if you have asthma – it improves lung capacity and blood flow, and has an overall calming effect.

Active people usually find they have fewer asthma symptoms and better control over their asthma. Sport and Recreation New Zealand (SPARC) recommends just 30 minutes of brisk walking on most days of the week. This can be in 10-minute bites if squeezing in 30 minutes a day is difficult.

There are many world-class athletes taking part in all sporting codes who do not let their asthma get in the way of achieving their goals. They control their asthma – not the other way around.

There are several things you can do to help manage EIA.

Control your day-to-day asthma

• If you have symptoms of asthma more than 3 times a week, your asthma is not well controlled.
• See your doctor to review your medicines and ask for an asthma self-management plan.
• Try to avoid exercising on days when you are experiencing more-severe asthma symptoms, eg, when you are getting a cold.

Do more asthma-friendly activities

Activities involving stopping and starting or a warm moist environment are less likely to cause EIA. For example, try walking, tramping, tennis, yoga, martial arts, T'ai chi, aerobics or team sports.

Remember to warm-up

Stretching and a few minutes of brisk walking or skipping before exercise:

• helps prevent EIA
• protects you from sprains and strains
• gets you in the mood to move.

Check weather conditions

• If you have a choice, exercise inside on cooler, dryer days.
• If you are outside and it is cold, wear a thin, warm scarf loosely around your lower face to help warm the air you breathe.

Use your reliever inhaler before activity

Take 1 or 2 puffs of reliever medicine (usually blue-coloured) just before you start physical activity. If you need to take reliever medicine more than once after your initial puff, stop your activity session for that day. Using a spacer increases the effectiveness of metered dose inhalers (MDIs).

If you exercise often and you need a dose of reliever before and during your session, ask your doctor to reassess your preventer medication. You might also like to discuss with your doctor whether long-acting inhaler relievers (symptom controllers) may be an option for you, as they often help people with EIA. You need to be taking regular preventer medication to be prescribed these.

Breathe – don't heave

Taking slow deep breaths through your nose with the right breathing pattern can help people with EIA (see below).

Breathe through your nose

• It is important to breathe through your nose as this warms, filters and moistens the air that enters your lungs.
• It also helps to regulate your breathing.
• Nose breathing may take practice, especially if you aren't used to it.
• If your nose is blocked by hay fever, dust mite allergy or sinusitis, ask your doctor about nasal treatments.
• Controlling any allergies and clearing your nose can make a big difference to your daily life and to your asthma.

Use your diaphragm to breathe

Your diaphragm is a large muscle separating your lungs from your abdomen. Your diaphragm can work hard and never get tired. Some people breathe using their chest muscles instead of their diaphragm. This takes extra effort and can cause fatigue and tension.

Test yourself to see whether you breathe correctly through your diaphragm (diaphragmatic breathing):

• Sit upright and relax your shoulders.
• Rest one hand on your chest and the other on your stomach.
• Breathe in deeply through your nose and pay attention to the movement of your hands.
• If you are using your diaphragm to breathe, the hand on your stomach will move.
• If you are using your chest muscles to breathe, the hand on your chest will move.
• Practice both ways of breathing and feel the difference.

If you are a chest-breather, practice diaphragmatic breathing for a few moments several times a day. Soon, diaphragmatic breathing will be automatic.

Relax while breathing out

It is important to relax and let the air flow out of your lungs slowly and freely. Take a moment to remind yourself how good it feels.

• Sit upright and relax your shoulders.
• Remember to breathe through your nose.
• Using your diaphragm, breathe in gently and fully, then just let go.
• Feel the air flow out fully and effortlessly.

Practice relaxing while you breathe out, and it will become automatic.

Breathe rhythmically

Most people breathe faster when they are tense or anxious. Their breathing becomes short and shallow. This type of breathing is both inefficient and tiring, and it can make you feel uptight or frightened.

Slow rhythmic breathing can help calm you. Practice this exercise several times a day.

• Sit upright and relax your shoulders.
• Breathe in gently and fully using your diaphragm.
• Let your breath flow out freely.
• To slow down, pause a moment before your next breath in.
• Aim for a rhythm of about 10–4 breaths per minute.