Exercise-induced asthma explained
Been diagnosed with exercise-induced asthma and wondering how it will impact your triathlon performance and training? Leon Creaney, a consultant physician in sport and exercise medicine, explains
Exercise-induced asthma is very treatable. Exercise is good for health, and long-term regular moderate intensity exercise is associated with better health, including respiratory. It’s also associated with better immune function. There’s some evidence that high-intensity exercise will transiently suppress immune function, leaving athletes temporarily vulnerable to colds for a day or two after hard training; but generally the benefits of exercise outweigh the negatives, even in asthma sufferers.
Asthma and exercise-induced asthma (EIA) are not exactly the same condition, although they often co-exist. Many highly trained athletes develop EIA even though they don’t have asthma normally, and the incidence of EIA is much higher in athletes than the normal population. It may be that regular intensive training actually provokes the condition. During intense exercise, the breathing rate increases, and cold, dry air can pass through the airways at higher rates than normal. This irritates the airways, making them inflamed, which can lead to narrowing and hyper-responsiveness of the airways. Because of this, a higher proportion of Olympic athletes than you’d expect are using asthma medications.
The diagnosis of EIA is usually made on the basis the symptoms – wheezing and difficulty breathing, during or after exercise. There are tests that can be done to verify an objective diagnosis, including measuring Peak Flows, both before and 5mins after exercise, and more advanced tests such as the EVH test (Eupcapnic Voluntary Hyperpnoea), which has to be lab-based. These tests are usually carried out on registered athletes, who need to prove to their sporting body and anti-doping agencies they really do have asthma.
Elites need to be very careful about which drugs they use. Many asthma drugs are banned, and will lead to positive doping tests. In order to use a ‘banned’ drug, the athlete needs to apply for special permission. The 2016 code states that: All beta-2 agonists are prohibited; Permitted exceptions are inhaled salbutamol (maximum 1600 micrograms over 24 hours); inhaled formoterol (maximum delivered dose 54 micrograms over 24 hours); and inhaled salmeterol in accordance with the manufacturers’ recommended therapeutic regimen.
For all sufferers, usually the aim would be for long-term suppression of the airway’s inflammation with a steroid inhaler. This ‘preventer’ minimises the symptoms, but it can take a few weeks to work. In summary, all athletes should be completely symptom-free with the correct treatment and able to train and compete as normal.