More and more children these days are going to the doctor with chest problems or shortness of breath during exercise, and are being diagnosed with asthma. Sometimes the doctor will prescribe one of the hundreds of available asthma medications, without any further tests. Yet there are simple and inexpensive tests that can be done.
The exercise challenge test, to determine if there is any indication of exercise-induced-asthma, involves exercise for ten minutes at a moderate workload based on predicted heart rate levels. This is often performed on a treadmill, but an exercise bike is just as effective. A nose clip should be worn to force breathing to be by the mouth only.
Lung function measurements are recorded before exercise and several times after exercise (for example: 1, 3, 5, 7 and 10 minutes post-exercise). If the lung function measurements are found to be worse compared to the test performed at rest, then exercise-induced-asthma is a possible explanation. A further test that can be performed if the lung function values are still depressed at ten minutes after exercise, is to take two puffs of a reliever medication (eg. Ventolin). After approximately ten minutes, giving time for the medication to take effect, another lung function measurement taken. If the measurements return to resting levels, then asthma was probably present.
A fall in these parameters of 10-25% is considered mild exercise-induced-asthma, a 25-35% fall moderate asthma, 35-50% moderately severe, and >50% severe.
During the exercise test, it is important to watch for signs of distress. A doctor should be available at short notice, and first aid procedures in place. The test should be stopped if the person is finding it very hard to breathe. In that case it is very obvious there is an asthmatic response.
What I have found conducting these tests regularly over the last few years, mostly on athletes of all levels, is that shortness of breath is not always an asthmatic response. Lung function values for some people are still normal. Maybe they are just unfit.
- See also Lung Function Tests
- The importance of breathing during exercise
- Food and its Effects on Asthma