We have all experienced it; a shortness of breath and sometimes even a feeling of gasping for air. Usually it is because of one simple reason: we are unfit or have pushed our bodies to the limit! For some people, though, this has nothing to do with either, as they suffering from exercise-induced asthma, a condition that can limit your running if you are unaware of it, but once it has been diagnosed it should not keep you from performing at your best. – BY CHANTELLE WEHMEYER
Exercise-induced asthma (EIA) is the sudden constriction of the bronchial passages occurring within a few minutes of strenuous exercise. This form of airway obstruction can even occur soon after finishing physical activity. It affects 12-15% of the general public and can affect anyone at any level of exercise participation. Approximately 80-90% of asthmatics will also have EIA while 40% of people with allergic rhinitis, atopic dermatitis or eczema will also suffer from EIA.
EIA exists in both mild and extreme forms. Not everybody suffering from EIA comes to a wheezing halt at the side of the road. Mild EIA includes the following symptoms:
• A sudden decrease in performance.
• Inconsistent performance.
• Energy loss after a workout.
The difference is that following a bout of exercise in so-called ‘normal’ individuals, early bronchodilation occurs. This, however, does not occur in patients with EIA; bronchoconstriction only occurs 6-8 minutes after exercise while lung function continues to decrease, with the peak effect about 15 minutes after exercise. Lung function usually returns to normal within two hours.
EIA seems to be a common problem among runners. This is because there is increased breathing during exercise, causing cooling and drying of the lining of the air passages. Normally, people breathe through their nose, which acts as an air filter. It controls the temperature and humidity of the air before it reaches the lungs.
When you exercise, your body requires more air, and the rate of breathing therefore speeds up. You start breathing through your mouth, gulping down more air. The air that comes through your mouth, however, has not been filtered, warmed or humidified by your nose. This means the air that gets to your airways is cooler and drier than usual and irritates inflammatory mast cells in the lungs, releasing chemicals that constrict airways. If you have a form of asthma, your extra-sensitive airways do not respond well to cool, dry air. Your airways react: the muscles around the airways twitch and squeeze tighter, meaning that there is less space for the air to pass through, making you wheeze, cough and feel short of breath.
WHAT WORSENS EIA?
Exertion above 75-80% of predicted maximum heart rate (calculated as 220 – your age) usually induces EIA. Factors that can affect the timing of onset and severity of EIA include:
• Environmental conditions such as temperature (worse in cold temperatures), humidity, air pollution and pollen.
• Underlying infections of the respiratory tract.
• Type, duration or intensity of the exercise.
• Lack of warm-up.
• The time elapsed since the previous exercise session.
• Activities such as running and cycling which require high-intensity exercise are most likely to cause EIA.
SYMPTOMS OF EIA
The symptoms of EIA include one or a combination of the following:
• Chest tightness.
• Chest pain.
• Prolonged shortness of breath.
• Extreme fatigue.
HOW DO I CONTROL IT?
Fortunately, with medication, monitoring and management one can participate in sport and achieve high performance levels. Many people only require pre-exercise treatment, whereas those with persistent asthma require daily anti-inflammatory therapy plus pre-exercise treatment. Warming up is one way to lower the risk of bronchospasm, as is working out in warmer weather or indoors. Those with mild symptoms can sometimes simply push through the spasms.
Taking medication prior to exercising is important in preventing EIA. Individuals who can tolerate continuous exercise with minimal symptoms may find that a proper warm-up may prevent the need for repeated medications. So you may be able to ‘run through’ your EIA either by warming up with short bursts of exercise, or by continuous exercise which does not bring on a severe attack.
Long-term anti-inflammatory medications such as inhaled steroids can reduce the frequency and severity of EIA. Inhalers do not cure the disease, but rather open the bronchial passages, making breathing easier. There are 3 common types of medications:
• A short-acting bronchodilator can prevent symptoms and should be taken 10-15 minutes before exercise. It will help prevent symptoms for up to four hours.
• A long-acting bronchodilator needs to be taken 30-60 minutes prior to activity and only once within a 12-hour period. Salmeterol can help prevent EIA symptoms for 10-12 hours. This should only be used to prevent symptoms and should never be used to relieve symptoms once they occur, because it does not offer quick relief.
• Cromolyn or Nedocromil need to be taken 15-20 minutes prior to exercise. This also should only be used as a preventative measure. Some individuals use one of these medications in combination with a short-acting bronchodilator.
All the ordinary asthma medicines used in the medically recommended way and dosage are acceptable to sporting bodies. Good control of your asthma, whether by breathing in a ‘preventer’ treatment or by avoiding the causes of asthma, can have a tremendous effect on EIA. Also, stress, illness and a general run-down condition will increase incidences of EIA.
Keep your inhaler close by when working out. If your asthma is well controlled, your airways will be less sensitive to exercise. Remember, it is also important to have strong breathing muscles. Exercise is therefore an important part of managing EIA!
Modern Athlete Expert
Registered biokineticist in Edenvale, Johannesburg.