For approximately 80-90% of people that suffer from asthma, exercise can be a strong stimulus for an attack. This syndrome has become known as exercise induced asthma or EIA. The likelihood of an attack is further increased when exercising in cold weather, so this article offers some basic information on exercise-induced asthma and how to prevent or minimize the severity of an attack.

Asthma is a condition where the subject experiences bronchospasms and/or bronchoconstriction - a narrowing of the bronchii (airways) due to excessive smooth muscle contraction, and inflammation. An asthma attack can be very frightening and in severe circumstances, result in death by asphyxiation (suffocation). With the initiation of exercise in healthy individuals and asthmatics, hormones such as adrenaline produce a relaxing effect on the smooth muscles of the airways (bronchodilation). However in asthmatics, this relaxation is followed by bronchospasm and usually begins within 5-15 minutes after exercise.

The reason for this bronchospasm episode is not known exactly, but sports medicine research suggests a strong connection to heat and moisture loss from the cells lining the airways. Air that is inhaled through the mouth must be warmed and humidified before passing further into the lungs. Cold air cannot hold much water vapor, and as a result is also typically dry; so it is suspected that cold-weather exercise/sports may be even more likely to trigger airway constriction. Running in cold weather and sports such as ice hockey are classic examples. Swimming on the other hand is thought to be a relatively safe sport for EIA sufferers.

With winter around the corner, here are a few tips to help minimize the chance of an exercise induced asthma attack.