Exercise-induced Asthma

Exercise-induced asthma, also known as exercise-induced Bronchoconstriction(EIB), occurs when physical activity causes your airways to narrow, increasing asthma symptoms. This could involve wheezing, coughing, or dyspnea. You can avoid asthma attacks and expand your airways by warming up, using inhalers, and taking other drugs.

What is Exercise-induced Asthma?

Breathing becomes difficult during exercise when your airways narrow, a condition known as exercise-induced asthma. During or after physical exertion, you could have asthma symptoms such wheezing, coughing, and shortness of breath.

When the air is dry and chilly, or when pollen counts and pollution levels are high, symptoms may worsen. Sports-induced asthma or exercise-induced bronchoconstriction (EIB) are other names for exercise-induced asthma.

How common is Exercise-induced Asthma?

Between 40% and 90% of asthmatics experience symptoms during or after physical activity. However, up to 20% of people in the general population, who may or may not have asthma, have exercise-induced asthma symptoms, proving that it can occur even in the absence of an asthma diagnosis.

Pathophysiology

A significant increase in minute ventilation and the demand on the respiratory system to heat and humidify the air with exercise-related hyperpnea cause evaporative water loss, thermal changes, and irritant exposure, which alter normal lung physiology and lead to exercise-induced bronchoconstriction.

There is a 200 L/min increase in ventilation, airway relaxing and mucosal dehydration. When cells get dehydrated, their pH rises and their size decreases, which causes coughing, mucus production, and the loss of the epithelium’s physical barrier function.

Edema and the release of inflammatory mediators, such as histamine, leukotrienes, cysteine, tryptase, prostaglandins, and mast cell degranulation, are believed to result from a regulatory increase in cell volume caused by decreased pH and elevated electrolyte concentrations.

Blood flow through the bronchi is enhanced. Increased lipid peroxidation results in the production of reactive oxygen species. Autonomic and sensory nerves are triggered. Direct and neural stimulation of bronchoconstriction are the outcomes.

Additionally, inadequate nasal breathing results in mouth breathing and increased lung surface contact to allergens, pollutants, and irritants, which causes reactive oxygen species to be produced as well as a neutrophilic inflammatory response.  

Those who have a genetic susceptibility to EIB may be less able to use cysteine to counteract oxidative stress. Mucus blocking and bacterial growth can result from modifications in mucus composition and a decline in mucociliary function.

Excessive physical activity has been connected to an increase in the condition and viral upper respiratory infections (URIs), and it can also cause temporary immune suppression with a shift to T2 cell response.

Prolonged exposure can cause asthma-like inflammation, remodeling, and epithelium damage and shedding. W hen exposure and exercise are discontinued, lung damage and hyperresponsiveness improve over the course of weeks to years, indicating that the process is somewhat reversible.

Evidence that the severity of EIB is strongly correlated with the rate of water loss in the airways, that EIB can be avoided by breathing in fully humidified air at body temperature, and that hyperosmolar saline can likewise cause bronchoconstriction all give support to the osmotic theory.
Increased exhaled nitric oxide and a higher number of epithelial cells in sputum samples, which are signs of greater airway inflammation, injury, and shedding in people with EIB.

Signs and Symptoms

The following are signs of Exercise-induced Asthma:

• Chest tightness.
• Coughing (for certain people, coughing is the only symptom).
• Breathing problems (shortness of breath). You can have trouble forcing air from your lungs.
• Mild to severe symptoms are possible.

• They may show up a few minutes after you begin working out or after you’ve completed a session. After resting for around half an hour, symptoms normally begin to get better.

• Asthma symptoms caused by exercise might occasionally reappear up to 12 hours after you’ve stopped exercising. Even when you’re sleeping, they can still show up. We refer to these as late-phase symptoms. Late-phase symptoms can persist for up to a day.

Causes

Exercise-induced asthma can be triggered by vigorous aerobic physical activity. It gets worse when:

• It’s dry and freezing outside.
• The level of pollen is high.
• Poor air quality is caused by excessive pollution levels.
• You’re recovering from a respiratory illness or cold.
• You’ve inhaled fumes from paint or cleaning products, smoke, or chemicals.

Activities that causes Exercise-induced Asthma:

Although symptoms can arise from any exercise, cold-weather sports and those requiring continuous physical exertion with little rest are the most likely to aggravate asthma. Among the examples are:

• Basketball.
• Ice hockey.
• long-distance running.
• Skating.
• Snowboarding.
• Soccer
• Lung irritation can also result while swimming, diving, or playing water sports in an indoor pool that has been chlorinated.

Risk factors for exercise-induced asthma:

• People with asthma and allergies are more prone to experience exercise-induced bronchoconstriction. It’s more common among professionals like Olympic athletes and professional football, soccer, and hockey players.

• Between 30% and 70% of professional sportsmen suffer from asthma caused by activity.

Prevention

You might be able to prevent an asthma attack with preparation and strategy. Prior to engaging in physical activity, you must:

• Give yourself enough time to warm up: Spend six to ten minutes warming up before beginning any physical activity. Your age, level of health, and sport or activity will all affect your warm-up routine. Consult to your Doctor about what’s best for you.

• Prior to exercising outside, check the air quality index and pollen levels: You might wish to stay inside if there is a lot of pollution and pollen.

• Cover your mouth and nose: To shield your airways from chilly, dry air, wear a mask, scarf, or gaiter.

• Control your asthma symptoms: When using inhalers and taking asthma treatments, according to your doctor’s directions.

• Inform teachers and coaches: Make sure coaches and teachers know if your child has asthma. Adults should be aware of the symptoms to look out for, how to assist with medicine, and what to do if symptoms arise.

• Keep a watch out for symptoms: Keep a look out for signs of sports-induced asthma in yourself or your child. If you see symptoms of an EIB episode, have a strategy in place. Keep in mind that symptoms may show up minutes or even hours after you stop working out.

• Select lower-intensity or indoor sports: You might wish to avoid some activities if you have asthma caused by athletics. The likelihood of experiencing symptoms is higher for endurance sports and activities that occur in colder climates.

Doing water sports in a saltwater pool or unchlorinated bodies of water could be beneficial if you enjoy them.

Which sports have a lower risk of causing Exercise-induced Asthma?

Sports that are played indoors, are less strenuous or only need brief bursts of exertion are less likely to cause an asthma attack. Among the examples are:

• Bowling, baseball, and fencing.
• Play golf.
• Gymnastics.
• pickleball.
• Runs.
• Tennis.
• volleyball.
• strolling.

Testing and Diagnosis

Your healthcare professional will inquire about the duration and timing of your symptoms. Additionally, they will inquire about any family history of asthma or other respiratory disorders. In addition to listening to your heart and lungs, they might run other tests. These consist of:

• Testing for pulmonary function: These assess the function of your lungs. One popular pulmonary function test for asthma is spirometry.

• Challenge yourself with exercise: An exercise challenge exam, also known as a bronchoprovocation test, involves running on a treadmill or riding a stationary bike or run on a treadmill. Before and after exercise, your healthcare professional measures your breathing using spirometry.

• Chest X-ray: To rule out infections or other possible causes of your symptoms, your doctor may recommend that you have a chest X-ray.

Differential Diagnosis

Exercise-induced symptoms such as coughing, wheezing, chest tightness, and dyspnea may be signs of airway pathology. Clinical symptoms alone are not always sufficient to diagnose exercise-induced bronchoconstriction; objective evidence of a decline in lung function with activity is needed.

The following are the most typical differential diagnoses for EIB Additionally, EIB may be linked to underlying illnesses like:

• Obesity and COPD
• pectus Excavatum
• Interstitial fibrosis and diaphragmatic paralysis:
• Vocal Cord Issues
• Tracheal and laryngeal processes
• respiratory tract infections
• Esophageal-gastric reflux
• hyperventilation syndromes

Treatment

Prevention and symptom relief are the main goals of treatment for exercise-induced asthma. Your doctor might recommend helpful drugs in addition to preventive measures like warming up before exercise. While some medications prevent symptoms, others widen your airways while you’re experiencing them.

• Medical treatment
• Physical therapy treatment

Medical treatment

Medications

Your doctor may prescribe drugs that you inhale through a nebulizer or inhaler. They can help relieve or avoid symptoms. Among the inhaled drugs for exercise-induced asthma are:

• Short-acting beta-agonists (SABAs): One kind of bronchodilator that relaxes the muscles in your airways is SABA. SABAs, also known as rescue inhalers, may reduce symptoms during an attack of EIB. Asthma symptoms can also be avoided by taking SABAs around fifteen minutes prior to engaging in physical activity.

• Long – acting beta agonist (LABAs): Another kind of bronchodilator that is used in conjunction with corticosteroids to treat asthma is LABAs; they are not used alone. If you inhale LABAs 30 to 60 minutes before exercising, they can help prevent an EIB episode.

• Corticosteroids: By decreasing airway inflammation, corticosteroids improve airflow. To avoid symptoms, your doctor could advise you to take them every day.

• Stabilizers for mast cells: Stabilizers of mast cells lessen airway inflammation. To help avoid symptoms, you can use a nebulizer to inhale this drug around fifteen minutes before exercising.

• Some people’s asthma symptoms can also be lessened by leukotriene modifiers and antihistamines.

Physical therapy Treatment:

Education

Some persons with EIB may find that the following advice helps them manage their symptoms in addition to taking their medications as directed:

• Getting warmed up before working out

• Being as fit as you can: Getting  raises the EIB threshold, which means that even moderately intense exercise may not trigger an attack.

• Avoiding areas with high concentrations of allergens, pollutants, irritating gasses, or airborne particles; instead, exercise in a warm, humid environment.

• Using the nose to breathe in order to warm and moisten the air

• Filtering air with a mask, while this can be inconvenient or make breathing more difficult

• Doing cooling exercises, inhaling through the nose, and covering the lips in cold, dry conditions after intense exercise

• If the customer smokes, think about discussing stopping with the doctor.

Acute Treatment:

Physical therapists may be the first to notice asthma symptoms in a patient with undiagnosed EIB because exercise triggers the condition.

Physical therapists must therefore be knowledgeable with the symptoms and indicators of EIB as well as any warning indications that might point to the necessity for medical referral and treatment.

The physical therapist should determine the intensity of the asthma attack and, if necessary, place the patient in high Fowler’s position for diaphragmatic and pursed-lip breathing if the patient experiences an acute asthma attack during therapy.

The physical therapist should support the patient in self-administering the medication while promoting relaxation if the patient has an inhaler available.

Long-Term Treatment

Patients with EIB may be discouraged from exercising for a number of reasons, including the perception that exercise is harmful to their illness.

There is substantial evidence to support the advantages of physical activity for cardiovascular training in this patient population, despite the lack of data supporting inspiratory muscle training or breathing exercises in asthmatic patients.

As a result, by educating patients and prescribing exercises, physical therapists can contribute significantly to the management of care.

The impact of physical therapy on children with asthma’s quality of life will be determined by a study procedure.

The Physical Therapy Guide to Practice lists the following Preferred Practice Patterns for this patient population:

• Pattern 6B: Deconditioning-Related Impaired Aerobic Capacity/Endurance

• Pattern 6C: Airway Clearance Dysfunction-Related Impaired Ventilation, Respiration/Gas Exchange, and Aerobic Capacity/Endurance

• Pattern 6E: Reduced Respiration and Gas Exchange Related to Ventilatory Pump Failure or Dysfunction

• Pattern 6F: Respiratory Failure-Related Impaired Ventilation and Respiration/Gas Exchange

FAQs

Reference:

• Exercise-Induced asthma. (2024, June 20). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/4174-exercise-induced-asthma

• Exercise-induced asthma – Diagnosis & treatment – Mayo Clinic. (2022, December 7). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/exercise-induced-asthma/diagnosis-treatment/drc-20372306