Asthma – What You Need to Know

Jarrod Wilson (Exercise Physiologist – Burnie)

What is Asthma?

Asthma is a chronic medical condition that affects the airways, leading to reversible airway obstruction. Asthmatic cases can range from very mild to severe with some cases even being life-threatening.

There are typically 3 main factors that cause the airways to narrow or become obstructed; these include:

• Swelling of the inside lining of the airways
• Increased mucus production and inflammation
• Tightening (spasm) of the muscles that surround the airways (bronchoconstriction)

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How Common is Asthma?

Asthma affects approximately 2 million people in Australia alone. This includes:

• 1 in 7 primary school children
• 1 in 8 teenagers
• 1 in 9 adults²

Asthma is more common in boys than in girls with a ratio of 3:2, however it is more common in older women than in older men.

There are an overwhelming number of people that don’t actually know that they have asthma.²

How Do I Know if I Have Asthma?

The common symptoms of Asthma include: shortness of breath, wheezing, coughing and tightness of the chest². Given the obstructive nature of the condition, there is greater difficulty when exhaling (breathing out). Asthma can be diagnosed by a GP based on how you describe the history of your symptoms. A spirometry test can also be used to assist a diagnosis.

What Causes Asthma?

Whilst the causes of asthma remain unclear, there are links to genetics and the environment. As asthma involves an inflammatory response, there are some obvious triggers that can lead to an exacerbation of asthma. These can include, but are not limited to:

• Allergens (dust, pollen, pets, etc.)
• Infection (particularly viral)
• Occupational exposure
• Medications
• Irritant gases, pollutants, chemicals
• Stress
• Cold air
• Smoke
• Exertion/exercise
• Obesity

How to Treat Asthma

For years asthma has been treated with 2 types of medication; ‘preventers’ or ‘controllers’ and ‘relievers’.

A ‘preventer’ is a corticosteroid medication usually taken daily to reduce the inflammation associated with the condition. Preventer medications help to reduce both the symptoms and the number of asthmatic attacks. This class of medication is particularly effective in reducing exercise-induced bronchoconstriction in most patients.

A ‘reliever’ is a bronchodilator taken when required. It should only be inhaled when required and in the lowest dose necessary to bring on relief. There are short and long acting relievers.

A discussion with your GP is often needed about what medication is right for your asthma.

Asthma and Exercise

Well controlled asthma should have no effect on someone’s ability to carry out exercise. With appropriate medication and management an asthmatic should be able to perform exercise at the same intensity as a non-asthmatic who is of similar size, skill and fitness level.

There is a phenomenon known as exercise-induced bronchoconstriction which can occur in people with or without diagnosed asthma and in all different fitness levels. This can often be a deterrent for those who would like to exercise but do not feel safe to. The good news is that despite research indicating that asthmatics tend to avoid exercise for fear of aggravating their symptoms, if the condition is managed correctly, exercise is beneficial in a majority of the asthmatic population.^3,4

An exercise-induced asthmatic attack is less likely with continuous aerobic exercise when compared to higher intensity, explosive or heavy resistance exercise, so selection of a suitable type of exercise is often important if you have poorly controlled asthma or if your asthma is exacerbated by physical activity.

It is important when starting out with an exercise program to commence at a low intensity and gradually progress the frequency, intensity and/or time of each exercise session. An appropriate warm-up to prepare the airways for subsequent exercise is important. A cool-down following an exercise session should also be performed.

How Can Exercise Help?

With control of the airways using inhaled corticosteroids and relievers as required, all asthmatics should benefit from a structured exercise program.

Exercise can be effective for asthmatics through aerobic conditioning. Generally speaking the higher the fitness level, the easier it becomes to take in and utilise oxygen from the air breathed in. This improved efficiency of oxygen-use results in a lower risk of an exercise-induced attack.⁵

Overall, exercise has been shown to help control asthma and decrease the reliance on medication.

For more information about the right type and amount of exercise for you, come in and see one of our Exercise Physiologists at Coastal Physiotherapy’s Burnie clinic.

References

1 https://www.americannursetoday.com/understanding-asthma-pathophysiology/

2. Morton, AR & Fitch, KD 2011, ‘Australian association for exercise and sport science position statement on exercise and asthma’, Journal of Science and Medicine in Sport, vol. 14, no. 1, pp. 312-16.

3. Chen, Y, Dales, R & Krewsky, D 2001, ‘Leisure time energy expenditure in asthmatics and non-asthmatics’, Resp Medi, vol. 95, no. 1, pp. 13-18.

4 Malkia, E & Impivaara, O 1998, ‘Intensity of physical activity and respiratory function in subjects with and without bronchial asthma’, Scand J Med Sci Sports, vol. 8, no. 1, pp. 27-32.

5 Henriksen, JM & Nielsen, TT 1983, ‘Effect of physical training on exercise –induced bronchoconstriction’, Acta Paediatr Scand, vol. 72, no. 1, pp. 31-6.