Inhalers, broncho-dilators, or "puffers" are indispensable to folks who suffer from asthma. Many fitness trainers have clients that arrive each session with an inhaler of some kind - to combat asthma attacks. Understanding the mechanism of an asthma attack allows you to design training programs that can avoid key triggers. Exercise induced bronchospasm (EIB) is a particular concern - since it is activity that triggers most attacks.

What is EIB?
EIB is defined as a narrowing of the airways induced by strenuous exercise and is very common in people who have been diagnosed with traditional asthma. Currently 14.6 million Americans live with asthma (Glaxo Wellcome, 1998). As many as eighty to ninety percent of those asthmatics will also experience breathing difficulties when participating in vigorous exercise (Lung Assoc. 1999). However a number of people that have not been diagnosed with asthma also present breathing problems during exercise. Fifty percent of people who experience hay fever and other allergic symptoms also report symptoms of EIB, and 10% of normal athletes have been found to develop EIB. Interestingly, a significant percentage of Olympic athletes (11.2%) were discovered to have EIB (Kyle et al. 1992). It should be noted that EIB is no longer referred to exercise induced asthma (EIA). Asthma is a condition characterized by breathing difficulties that can occur at anytime or after exposure to a variety of stimuli. EIB is more specific terminology that refers to those breathing difficulties that develop as a result of activity.

Diagnosis of EIB is usually based on past history of respiratory distress associated with vigorous exercise. Clearly those patients already diagnosed with asthma seemed to be easily diagnosed with EIB as well. Those asthmatic individuals who experience severe symptoms during exercise likely report them to their physician and receive a diagnosis and treatment recommendation. Some signs that may indicate a person has EIB include a history of cough, chest tightness, dyspnea or wheezing after exercise. Additionally be cautious if a client becomes easily winded during a new conditioning program or appears "out of shape" after several weeks of training. A trainer who observes these signs and symptoms might want to encourage their client to visit their physician and get a pulmonary function test to rule out EIB (Kyle et al. 1992).

Triggers & Attacks
Episodes of EIB differ from asthma in that they usually occur suddenly after the onset or termination of exercise whereas asthma attacks tend to develop more slowly from environmental triggers or viral infections (Lung Assoc. 1999). Triggers of EIB include pollutants like sulfur dioxide (in gas or aerosol form) and ozone, a well-recognized airway irritant. Beta-receptor antagonists like propanonol may also induce EIB in some individuals (Virant, 1992). Most scientists agree that factors like cold air, low humidity and normal hyperventilation that occurs during exercise are definite triggers of bronchoconstriction.
All people experience some bronchodilation in response to exercise. Normally the glottis widens and bronchodilation occurs in order to meet the greater oxygen demands placed on the body during exercise. In people with EIB the glottis widens but the lower bronchioles constrict and restrict oxygen intake, this results in increased respiratory demands (Rupp, 1996).

Prevention
Perhaps the most effective means of preventing or reducing severe EIB incidents is the use of pharmaceutical bronchodilators. Pharmacological treatments should be tailored to the individual and the activity that they will be engaging in. Be sure to have new clients inform their physician about their change in activity levels, they may need to make treatment adjustments.
Non-pharmacological treatments that may reduce the severity of EIB include extended warm up and regular physical exercise. Extended warm-up periods of activity performed at sub-threshold exercise levels for 8-10 minutes allow the athlete to gradually ease the body into the activity and possibly avoid sudden trigger of EIB. Another option is a warm up that includes short bursts of high intensity exercise to attempt to induce a refractory period. A significant percentage of athletes experience a refractory period following an initial EIB episode instigated by warm up or pre-event activities making them resistant to another episode in later activity or competition (Kyle, et al. 1992). Long warm up periods are not recommended in place of pharmacological treatment, but can be useful in the overall treatment. Similarly, regular exercise has been effective in reducing the onset and gravity of EIB episodes. (Storms & Joyner, 1997).

Regular exercise is beneficial for people EIB for two main reasons, the first being that the conditioning that occurs through exercise alleviates sensitivity to some EIB triggers. The second reason is participation in exercise (in conjunction with appropriate pharmacological treatment) can enhance self-image and eliminate many stereotypes associated with asthma (Disabella & Sherman, 1998).

With proper treatment there is no reason for people with EIB to avoid or miss out on the benefits of athletics and physical activity. All people with EIB should be encouraged to exercise. Exercising safely and effectively means carrying a rescue inhaler with you at all times - even though you may not need it every time (Disabella & Sherman, 1998).

Guidance
The exercise prescription for people with EIB is varied from individual to individual, but some guidelines that have been shown effective are as follows:

• Extended warm ups performed at 60% of max for at least 15 minutes or 20-30 minutes at a lower intensity.
  
  
• Attempt to induce a refractory period by performing 30 second sprints separated by short intervals.
  
  
• Participate in at least 20-30 minutes of cardiovascular activity at 60-85% of predicted maximum heart rate four or five times a week.
  
  
• Avoid exercising in cold weather or in areas with elevated air pollution
  
  
• Avoid exercising when breathing difficulties are already present, such as wheezing, allergies, and respiratory infection.
  
  
• Never train an asthmatic person who does not have their inhaler with them.
  

References

Disabella, V. & Sherman, C.. "Exercise for Asthma Patients: Little Risk, Big Reward". Physician and Sports Medicine, 26, (1998).

Gershwin, M. E.. "Exercise Induced Asthma". Allergy and Asthma Magazine: Professional Edition, 5, (1999). Online.

Glaxo Wellcome. "Asthma Care in America Falls Far Short of National Treatment Standards. Asthma in America, (1998). Online. www.asthmainamerica.com/newsrelease.htm

Kyle, J.M., Walker, R.B., Hanshaw, S.L., Leaman, J.R., & Frobase, J.K.. "Exercise-induced bronchospasm in the young athlete: guidelines for routine screening and initial management". Medicine and Science in Sports and Exercise, 24, (1992).

Moeller, J.L. "Contraindications to Athletic to Participation: Cardiac, Respiratory, and Central Nervous System Conditions". Physician and Sports Medicine, 24, (1996)

Rupp, N.T.. "Diagnosis and management of exercise induced asthma". Physician and Sports Medicine, 24, (1996).

Storms, W.W. & Joyner, D.M.. "Update on Exercise Induced Asthma: Report of
the Olympic Exercise Asthma Summit Conference". Physician and Sports Medicine, 25, (1997).

The Lung Association. "Asthma and Exercise: Exercise Induced Bronchospasm". (1999). Online. www.lung.ca/asthma/exercise/eib.html

Virant, F.S.. "Exercise-induced bronchospasm: epidemiology, pathophysiology, and therapy". Medicine and Science in Sports and Exercise, 24, (1992).