Food and Fitness: asthma

A respiratory disorder characterized by recurrent attacks of difficulty in breathing (described in medical books as ‘episodic wheezing’), particularly on exhalation. It is caused by an increased resistance to air flow through the respiratory bronchioles (small air tubes leading to the lungs). Sufferers are hypersensitive to a variety of stimuli (e.g. house dust mites; diesel exhaust particulates; and vehicle exhaust gases, such as ozone and nitrogen oxides) which cause the airways to narrow. Asthma may be induced by exercise and food allergies. Sports vary in their tendency to induce asthma, with running having a high tendency, cycling a moderate tendency, and gymnastics and swimming a low tendency. Paradoxically, many asthmatics gain relief from bronchospasms by regular exercise, and exercise is now seen as important in the management of asthma. Asthmatic attacks are relieved by a number of drugs, but competitive sports people should be aware that some of these are banned by sports federations because, as well as controlling asthma, they may act as artificial stimulants.