Exercise-induced asthma (also known as EIA) occurs due to an increased volume of breathing brought about by the demands of physical effort. The theory generally accepted among researchers is that increased ventilation cools and dehydrates the airways. With increased ventilation, airways are required to condition a greater volume of air and this causes the dehydration and cooling effect. According to Anderson, the greater the volume of ventilation, the greater the loss of water and cooling of the airways and so the greater the severity of bronchoconstriction. Estimates at the incidence of exercised induced bronchospasm are anything between eighty per cent and ninety per cent.
Buteyko cites the loss of carbon dioxide as playing the primary role. If the volume of air being breathed is greater than is required by the metabolism, the airways narrow and asthma symptoms occur. When this happens, the amount of carbon dioxide being breathed out is greater than the amount the metabolism is producing. This results in activation of the body’s defence mechanism as it constricts the airways to prevent the loss of carbon dioxide.
Buteyko’s theory carries a lot of weight because during physical activity ventilation increases far more than it would at rest. However, when the control pause is sufﬁciently high, there are no symptoms during exercise due to the muscles producing plenty of carbon dioxide to counterbalance the increase of breathing. If EIA were caused solely by airway dehydration, then surely symptoms would occur regardless of the CP or degree of exercise? Another question worth asking is: if airway cooling, or drying, is the cause of EIA, then at what temperature or air moisture content could exer- cise be taken in order to prevent an attack? Would an attack occur if exercise were taken in a steam room, for example? Quite possibly all theories have a validating argument but it does not matter which theory is correct. The most important thing to recognise is that overbreathing causes bronchoconstriction.
How do you know if you are exercising correctly?
You are exercising correctly if you can achieve the following: nasal breathing, an improved control pause and if you no longer require reliever medication prior to exercise.
Nasal breathing: It is of the utmost importance that all breathing is done only through the nose, and especially when the CP is low. This comes as quite a shock to most people because mouth breathing is so predominant in every activity, including walking. When the change to nasal breath- ing is ﬁrst made, ﬁtness levels will tend to dip below the normal level. However with continued nasal breathing this will soon correct itself. Research conducted with top athletes has shown that ﬁtness levels will improve substantially within eight weeks if nasal breathing is maintained. It is essential in reducing exercise-induced asthma and it is advisable for people involved in sports to train at a more relaxed pace until they become accustomed to nasal breath- ing. Once the new regime becomes like second nature more intensive training can be undertaken.
Regardless of what type of exercise is being undertaken, if the need to breathe in through the mouth arises then the training is too intense. For chronically ill people, this can occur after just a few steps. For people who are physically ﬁt this may not occur until after a few miles of jogging. As soon as the need to breathe in through the mouth arises, it is important to stop and relax, wait for a few minutes to catch a breath and only then proceed with the exercise once again. For this reason, walking in a park where there are plenty of seats is a good idea. This affords the opportunity to sit down on a bench and relax for a few moments whenever the need to breathe through the mouth occurs. In a matter of just a few weeks it should be possible to walk the entire distance without having to sit down and the route should be a lot easier to complete than previously.
It is often pointed out that nasal breathing can become quite pronounced and audible during even mild exercise. The body’s requirement for air increases substantially with any exercise. As a result the breathing becomes louder and many people are conscious that other people can hear them breathing while they are out walking. This is only a tempo- rary state and breathing will reduce as the levels of carbon dioxide increase. Whatever happens it is important not to revert to mouth breathing.
Reliever medication: Only take short-acting reliever medica- tion if it is really needed; this is accepted medical practice. Never take reliever medication if it is not needed because it is easy to develop a subconscious dependence on quick- acting reliever medication. Quite often an inhaler is taken out of habit rather than need. At the same time, continue to have the reliever close to hand just in case it is required mid- way through training. It is proven that a tolerance to reliever medication occurs over a period of time and this can result in more and more puffs being needed to reduce symptoms.
Asthma is a defence mechanism to prevent the further loss of carbon dioxide. When the airways constrict this is the body’s way of reducing hyperventilation. If ﬁve puffs of reliever medication are typically required during a football match, then the asthma is totally out of control. It would be far safer to reduce the intensity and/or duration of exercise until such a large dose of medication is no longer required.
Controlled breathing during sports: All this might seem to indicate that people with asthma won’t be able to compete at the top level in their chosen sport but, in fact, nothing could be further from the truth. Everything that an individual can do with the aid of relievers can be done without the need for medication – as long as attention is paid to breathing.
It is relatively easy to combine controlled breathing with sport, with the exception of sports that require intensive bursts such as sprinting. For example, playing football should not present a problem if a gentle and gradual warm-up is performed ﬁrst. Other steps to aid breathing can also be taken during the match. When the ball is elsewhere, breathe a little less than is required and when running for the ball try to keep breathing through the nose. If it gets to the stage where the need arises to breathe through the mouth, calm the breathing and switch to nasal breathing as soon as the ball has been passed. If the need to breathe through the mouth for long periods occurs, then it is better to stop playing football until such breathing becomes easier and it is possible to play at the desired level. Continuing to play while not breathing properly will not help people with asthma. So while playing try to ensure the breathing is not too deep and remember to observe the breathing pattern as much as possible.
Walking for half an hour every day is probably the best exercise for anyone who has not been taking regular exercise. Initially it may be best to walk alone rather than having to keep pace with someone else. Walking alone also avoids talking which promotes mouth breathing and increases hyperventilation. While walking, breathing should be reduced and again if at any time the need to deep breathe is experienced while walking or doing any exercise, then slow down and relax. Resist the urge to breathe through the mouth and, instead, stop and calm the breathing and when ready start walking again.
Those people whose asthma is severe and who can only walk around twenty paces should start by just walking ﬁfteen paces and stopping. Breathing should be reduced and it is important never to push the body beyond the point where breathing cannot be controlled; to do so would be counter- productive and potentially dangerous. Don’t be too con- cerned by needing to start at a very modest level; perseverance will result in being able to gradually walk further and further.