Exercise as it relates to Disease/Asthma and Winter Sport Athletes

What is Exercise Induced Asthma
Asthma is a condition that restricts airflow available to the lungs as a result of constriction of the bronchioles by contracting smooth muscle and increased mucous production. Asthma is a chronic disorder of the airways and attacks can be initiated by certain triggers. Like asthma exercise induced asthma (EIA) reduces the airflow available to the lungs and exercise is the trigger for the asthma incident. Symptoms include shortness of breath, dyspnoea, wheezing, coughing and chest pain and can occur during or post exercise. Exercise induced asthma can occur in people with chronic asthma and also in people who experience no asthma symptoms other than during exercise. In some people exercise induced asthma only occurs in extreme environments such as cold weather. In some athletes EIA symptoms may only be prevalent intermittently and may only occur at high intensities.

Implications for Winter Sport Athletes
Although exercise induced asthma is affected by many factors cold weather is thought to play a significant role in its onset. Up to 50% of winter sport athletes suffer from EIA due to the cold environments they train and compete in. Many winter sports are played in sub zero temperatures increasing athletes’ risk of EIA due to the exposure to cold temperatures and low humidity. Training and competition, especially endurance events, results in a higher ventilation rate which also contributes to the occurrence of EIA.

How Cold Weather Affects Asthma
The exact mechanism for how cold weather may affect EIA is unclear but it is thought that it is caused by the cooling and drying of the airways as a result of exposure to cold dry air. Increased ventilation rate during exercise increases the risk of EIA as it means that a higher volume of cold air is in contact with the airways, drying and cooling the bronchioles. At higher ventilation rates people breathe through their mouths rather than their nose. When breathing through the nose the air is humidified and warmed prior to entering the bronchioles, this doesn’t occur when breathing through the mouth meaning that the air is colder and drier which increases the risk of EIA.

Considerations to Minimise EIA in Cold Weather
Exercise has positive benefits on asthma and can decrease the severity and incidence of attacks. The exercise intensity that is required for EIA to occur can also be increased with exercise. In most people with proper management and control asthma shouldn’t be a barrier to participating in sport and many sufferers of EIA are successful at the elite level,.

To reduce the risk of EIA an athlete can:

•	 Perform a proper warm up and cool down

•	It may be possible to induce EIA during the warm up to make use of the refractory period where another attack can't occur. The refractory period lasts from two to four hours and exercise should be undertaken during this period.

•	Wearing a mask or scarf that covers the mouth and nose can also be beneficial in athletes with EIA as it warms the air.

•	EIA can be managed reasonably well in most asthma sufferers through the use of medication. It should be considered however that some asthma medications such as beta 2 agonists are on the WADA restricted list and some other sporting authorities also have restrictions on these substances. For this reason it is important that the athlete notify their sporting organisation of the use of these drugs and provide evidence from a medical practitioner that the athlete suffers from EIA.

•	Have an asthma action plan in place that is known by coaches, teammates, support staff and others associated with the athletes training or competition so that others know what to do in the event of an attack. An asthma action plan can also help others to identify symptoms of an attack.