February 20, 2006
For gold-medalist Beckie Scott, competing in the 2006 Olympic Winter Games in Turin, Italy means the opportunity to duke it out with some of the fiercest cross-country skiers in the world. It also means contending with some of Italy’s harshest environmental conditions. As a matter of fact, racing in temperatures of -15°C is a non-negotiable part of Olympic competition.
A recent study conducted by scientists in Finland suggests that prolonged exercise in cold, dry air may have adverse, long-term effects on the respiratory systems of endurance athletes, such as cross-country skiers (Pohjantähti et al, 2005).
The 2005 experiment compared the occurrence of asthma, or exercise-induced bronchospasm (EIB), among healthy elite cross-country skiers and their non-athletic control subjects.
The word “bronchospasm” refers to unwanted activity that happens in the lungs, making it hard to breathe; if you’ve already learned about the lungs, you will remember that the bronchi and bronchioles are the tubes that carry air deep into the lungs. Unwanted spasms in the muscles wrapped around the bronchioles will make these tubes narrower.
Another cause for brochoconstriction, which is just a fancy way of saying that the bronchioles have gotten narrower, is inflammation in the respiratory tract (i.e., lungs). This happens when the immune system gets carried away. ( NOTE: for more on “unwanted inflammation” see January’s issue of Homework, “Chemical Combat Against Acne”)
But, back to the Finish study…Twenty healthy elite cross-country skiers and 18 non-asthmatic, non-athletic individuals were challenged by a standardized free exercise test. The subjects were then tested for EIB.
Nine subjects in total showed signs of EIB and reported asthma-like symptoms, such as dyspnea (or “air hunger”), cough, or increased mucus excretion. Seven of the nine were from the group of skiers and the remaining two were from the control group. With this 7:2 ratio of EIB sufferers, researchers concluded that EIB is more common in elite cross-country skiers than in non-athletic individuals, but were unable to pinpoint exactly what caused the inflammation of the respiratory tracts in the first place.
The bronchoconstriction found in subjects with EIB showed to be mild-to-moderate. But keep in mind that a tiny change in the size of an athlete’s airway can make a big difference, especially in sports where a millisecond can mean the difference between silver and gold.
Think of it this way: imagine that you are very thirsty, and had to drink a glass of water through a straw. Which straw would you choose: a regular-sized straw or a super-skinny straw?
Of course you would choose the regular straw, which would allow you to drink the greatest volume of water with the least amount of effort.
If the respiratory tract is inflamed, it means that it is narrower than usual. The athlete’s ventilation (breathing in and out) is therefore not occurring at an optimum level. This means that the athlete will not be able to achieve his or her peak performance.
Like having to drink through a skinny straw, the athlete with the constricted airway will not be able to deliver oxygen to the body’s cells quickly enough.
Anybody who exercises outdoors in the wintertime knows how grueling it can be; the sting of frosty wind beating against the face, and the shock of cold, dry air in the lungs is enough to send anyone huffing and puffing all the way home.
Top-notch athletes, who have dedicated their lives to their sport-of-choice, are unlikely to quit or change professions because of the weather. So what can these cold-weather competitors do to minimize the threat that cold, wintry conditions may have on their performance in Torino?
Fast-acting medications, approved by the International Olympic Committee, can be very helpful if they are used directly before exercise. Inhalers that contain anti-inflammatory agents or bronchodilators work by reversing the narrowing of bronchioles, and help expand the airways to improve the breathing capacity of patients. The benefits can last for hours.
Some cross-country skiers wear breathing masks or scarves, which can pre-warm and humidify the air slightly. This way, the air coming into athletes’ lungs is moistened, and less likely to induce asthma.
Exercising in cold weather conditions poses few risks to health and performance to the average person. But for the athletes vying for gold in the 2006 Winter Olympic Games, the proper combination of preventative measures will undoubtedly be taken.
Pohjantähti H, Laitinen J, Parkkari J. 2005. Exercise-induced bronchospasm among healthy elite cross country skiers and non-athletic students. Scandinavian Journal of Medicine and Science in Sports 15:5 324-28.
Katherine is a first year Masters of Journalism student at the University of British Columbia. Although she earned her bachelor degree in Honours English, she has always been interested in Sciences; she even enrolled in Chemistry, Biology, Organic Chememistry and Physiology as an undergrad at Huron University College. CurioCity offers Katherine a great opportunity to combine her love of writing with her fascination for Science.