Exercise Induced Asthma (EIA) or Exercise Induced Bronchospasm
(EIB) refers to asthma that occurs only with exercise. The
reported incidence of EIA varies between 5% and 20% of the
During start of exercise pulmonary functions tends to be normal,
but within 5 to 10 minutes symptoms of asthma such as wheezing,
breathlessness, tightness of chest appear. Patient may also feel
extreme fatigue. After a rest period, the symptoms subside. But
sometimes symptoms may become worse for a longer time.
Hyperventilation and airway cooling are the two most important
triggers of EIA.
People with exercise induced asthma have airways that are
sensitive towards changes of temperature and humidity.
Hyperventilation during exercise is the primary event which
causes cascade of events leading to EIA. Hyperventilation causes
drying of the airway surface epithelium where by causing
dehydration of the airway cells and increased intracellular
osmolarity. The increased osmolarity results in the release of
mediators from mast cells and damage airway epithelial. The
mediators released during EIA include histamine, leukotrienes,
cytokines, etc. All these events are called inflammatory
reaction which is the root cause of asthma.
but less important cause of EIA is the airway cooling that is
found with hyperventilation during exercise. During rest we
breath through nose. Nose has a temperature and humidity control
mechanism that makes air humid and at body temperature. When we
exercise we breath through mouth, our respiration becomes rapid
(hyperventilation). This forces cold and dry air into the
airways. After the exercise is over, the small bronchiolar
vessels around the tracheobronchial tree warm up, and this
reactive hyperemia leads to exudation of serum into the
interstitial fluid and release of mediators that subsequently
causes airway muscles to contract and also walls of airways
become inflamed resulting in narrowing of airways.
How is exercise induced asthma diagnosed?
Diagnosis of EIA can easily be
made symptomatic. Person is usually normal before exercise.
During exercise he experiences shortness of breath and/or chest
tightness, wheezing, and cough.
After a period of rest , the symptoms subside. Sometimes
symptoms such as prolonged cough after exercise, chest pain and
fatigue may last longer.
The diagnosis of EIB can also be confirmed by a variety of
tests, such as exercise challenge, methacholine challenge, or
eucapnic voluntary hyperpnea. The International Olympic Medical
Commission recommends any or all of these tests, but in most
cases the Eucapnic Voluntary Hyperventilation (EVH) test is the
easiest to perform. If exercise challenge is to be performed,
then this should be done in the athlete's sport.
"Pure" EIA and persistent asthma
with an exercise exacerbation can be differentiated by
spirometry. During rest if the forced expiratory volume in 1
second (FEV1) is not normal, patient is administered an inhaled
beta-agonist and test is repeated after 15 minutes. If the FEV1
improves 12% or more, that is an indicator of mild persistent
asthma, and the patient should be treated
for the persistent asthma in addition to the EIA.
A 15% drop in FEV1 after 6 minutes
of running or other exercise can be diagnostic of
exercise induced asthma.
What is the treatment of
exercise induced asthma?
Treatment of EIA is same as that
of asthma. Short-acting beta-agonists, such as albuterol
(salbutamol) are use full before exercise. Albuterol should be
taken 15 minutes before exercise to reduce chances of EIA.
Inhaled steroids are also very effective for EIA but must be
given daily and take about 2 weeks for effectiveness. Cromolyn
and nedocromil can be given just prior to exercise like
albuterol and work quite well.
Leukotriene modifiers, such as montelukast, are given as a daily
pill and do help reduce EIA, but they are not as effective as
the inhaled products. Some patients may benefit from
anticholinergics, such as Ipratropium.
Many patients may require two or three medicines to treat EIA
High-intensity warm-up before the exercise is helpful for
reducing the EIA. A low-salt diet and fish oil supplementation
are other nonpharmacologic therapies that have been shown
to reduce airway
inflammation and reduce EIA.
What is the precaution I can take to prevent the attack?
With proper control of asthma, most adults and children with
asthma call participate fully in physical activities.
If needed you should take 2 puffs of short acting reliever (one
with blue cap) inhaler 15
minutes prior to exercise. This usually prevents the
beneficial for EIA patients as with rest of people?
the risk of cardiovascular disease, diabetes, obesity and other
health related problems in asthmatic person as in any other
Aerobic exercise programs have shown to reduce airway
responsiveness in patients who do them regularly.
Studies also suggests that asthma sufferers who exercise
exacerbations, use less medication, and miss less time from work
What are the exercise goals for asthma patients?
The exercise goal
for people who have asthma, as for most people, should be 20 to
30 minutes of activity that raises heart rate to 60% to 85% of
maximum, four or five times a
Which sports/ games are more suitable for EIA patients?
like swimming, running or biking or which exposes the exerciser
to warm, humid and moist air that tempers the effect on the airways are
more suitable for asthmatic patients. The sports that require
short bursts of activity interspersed with breaks, are least
trigger asthma attack.
Some of the sports that are least likely to induce EIA are:
Short-distance running and track/field events,
Recreational biking (not racing),
Baseball or softball,
Yoga may help manage asthma. Sahaja yoga is a type of meditation
based on yoga principals that
was found to be somewhat effective in managing
which days I should skip exercise?
If you are
wheezing, when allergies are particularly troubling, or when
peak flow testing suggests a decline in lung function. These are
signs that you have higher chances of
induced asthma on that particular day.
Is it risky to
exercising when pollen counts are high in the environment?
EIA is believed to
be inflammatory in nature but another stimulus an allergic
asthmatic reaction due to inhaled airborne allergens in the EIA
patient with inhalant allergies may also be present. These two
stimuli (exercise and inhaled allergens) may be additive or
Exercising when pollen counts are high may cause more severe EIA
in EIA patients allergic
Also read <How
to control asthma triggers>
Which is the
most common condition mimicking EIA?
dysfunction is a disease that mimics EIA. In
dysfunction the patient has inspiratory stridor because of
partially closed vocal cords. Patients complain of throat
tightness rather than a chest tightness. These patients also
have the major symptom of dyspnea with little or no wheezing or
In these patients the usual medications for EIA are not helpful.
The diagnosis is best made by rhinolaryngoscopy after exercise,
showing closure of the cords on inspiration. But vocal
cord dysfunction may coexist with EIA making diagnosis
Winners With Exercise Induced Asthma:
What do Jackie
Joyner-Kersey, Dominique Wilkins, Nancy Hogshead, , Bill Koch,
Greg Louganis, Jim Ryun and marathon runner and world record
holder Haile Gebrselassie have in common?
They are world
famous athlete who has asthma. They come from diverse fields:
swimming, track and field, cross-country skiing, diving,
basketball, and long-distance running. Studies have shown that
up to 35% of students and 50% of elite cold weather athletes may
have EIA. Properly following their
Asthma Action Plan help them
Which sports are more likely to cause
Sports and games that are played in cold weather or require
continuous exercise or activity are most likely to trigger an
Hockey (ice and field),