We all recognise that in todays modern and often mostly sedentary society, that exercise is good for you. Regular exercise can reduce your risk of heart disease, lower your cholesterol, help to control your weight and improve your confidence and general well-being. But is it safe for those who suffer from chronic asthma?
Firstly let’s look at what exactly is asthma, what is the classic “asthma attack” and why does it happen?
Asthma is a chronic inflammation of the airways – or bronchial tubes – inside the lungs.
An asthma attack is a sudden worsening of asthma symptoms caused by the tightening of muscles around the airways, this is called a bronchospasm. During the asthma attack, the lining of the airways become swollen or inflamed and thicker mucus, more than normal, is produced. All of these things cause the symptoms of an asthma attack such as difficulty breathing, wheezing, coughing, tightening in the chest, shortness of breath. There are many different things that may trigger an asthma attack including allergies to pollens and grasses, stress, very cold and dry air and also exercise induced asthma.
So does this mean that people with asthma shouldn’t exercise? To answer this question we need to look at how exercise can at times trigger an asthma attack.
When we breathe more heavily during exercise large volumes of air are breathed in. Now under normal conditions when we are breathing quietly, about one 4.5 litres of air enters our lungs during each minute. The air that enters the lungs is warmed and has moisture added to it by the nose, mouth and throat. By the time the air reaches the bronchial tubes inside the lungs, it has nearly the same temperature and moisture as the walls of the bronchial tubes themselves. If for example you run to catch the bus your level of breathing may double or triple to 9 or 12 litres per minute or more. Then you exceed the ability of the nose and mouth to warm and humidify completely the inspired air. This dry air causes the bronchial tubes to become irritated, narrow and spasm – a classic asthma attack.
So how does swimming fit in?
When you are swimming the air is more humid and warmed due to the aquatic environment and so the effect on the bronchial tubes is much less severe. As previously discussed swimming also increases cardiovascular endurance. A recent article in “Cochrane Database of Systematic Reviews" investigated the effect of swimming training on subjects younger than 19 with stable asthma. The authors concluded that swimming improves lung function, and heart and lung fitness. There was no evidence that swimming had negative effects on asthma control or flareups.
A study conducted by The Department of Paedatrics, University of Maryland School of Medicine, Baltimore US, found that asthmatic children who were involved in a two-month, consistent program of swim training, showed “significant improvement in all clinical variables”, including “symptoms, hospitalisations, emergency room visits and the school absenteeism compared with their previous medical history or to those of age-matched controls. In addition, these benefits were more visible even up to a full year after the program was discontinued.
Additionally, in a study published in Respirology lead author, Wang Jeng-Shing from the Taipei Medical University states "Unlike other sports, swimming is unlikely to provoke asthma attacks. In addition to improving asthma, swimming promotes normal physical and psychological development, such as increasing lung volume, developing good breathing techniques and improving general fitness,"
As always safety is of the utmost importance. If your child has an asthma attack in the pool, get them out and give them their reliever inhaler immediately. If the situation fails to improve quickly make the lifeguard or nearest member of staff aware and ask them for help and request urgent medical assistance.