An estimated 26 million Americans—about one in 13—live with asthma, according to data from the Asthma and Allergy Foundation of America. Asthma is a chronic inflammatory disorder of the airways that impacts genetically vulnerable persons in response to various environmental triggers, such as allergens, cold, exercise and viral infections. Asthma symptoms include chest tightness, coughing, varying degrees of difficulty breathing and wheezing.
Although physical activity confers a wide range of health benefits, it can aggravate or worsen asthma symptoms, which may lead to inactivity and decreased conditioning. Reduced fitness can lead to a downward spiral, as asthma symptoms are then provoked with less-intense exercise, which may make people less likely to be active, which further reduces their fitness level, and so on. Exercise-induced bronchoconstriction (EIB) is defined as transient and reversible airway narrowing that occurs because of exercise. EIB can be triggered in active persons of all ages and across numerous types of activities/sports.
Fortunately, as a health and exercise professional, you can work closely with clients who have asthma and/or EIB to design and implement exercise programs that minimize symptoms and exacerbations. This article outlines strategies for helping clients who have asthma or EIB perform exercise safely and effectively.
The Basic Mechanisms of Asthma and EIB
An appreciation of the underlying mechanisms of asthma and EIB can help you develop more individualized, safe and effective programs.
Figure 1 illustrates the relationship between airway inflammation, airway hyperresponsiveness, airway obstruction and symptoms (e.g., shortness of breath and wheezing). It is critical to recognize that the cascade of events that eventually leads to the various asthma- and EIB-related symptoms is first set in motion by inflammation (i.e., activation of inflammatory cells and inflammatory mediators, as shown in the diagram). The triggering of inflammation is the result of exposure to various stimuli. Eventually, the inflammation leads to narrowing of the airways and tightening of the muscles that surround your airways (i.e., bronchospasm). This makes it more challenging to transfer inspired oxygen through the respiratory system and to the rest of the body.
When a client experiences this sequence of events, it will be visible at the whole-body level and they will experience a noticeable reduction in exercise capacity. If the narrowing of airways and bronchospasm is severe enough, it can result in a medical emergency, as your client will not be able to breathe. Initiating emergency response is warranted in this scenario.
Figure 1: Relationships among airway inflammation, airway hyperresponsiveness, airway obstruction and airway symptoms
As noted in Figure 1, exposure to stimuli triggers the initial inflammatory responses and further leads to airway hyperresponsiveness. As such, knowing and avoiding your client's triggering stimuli will reduce the risk of asthmatic and EIB-related responses, and is an important preventative strategy to follow. In general, there is a dose-response relationship among three factors and risk of asthmatic and EIB-related symptoms:
- Concentration of stimuli
- Duration of exposure/total time of exercise or physical activity
- Ventilation rate as determined by exercise intensity
An increased dose of one or more of these factors increases the risk of symptoms. For instance, a higher concentration of smoke or pollen may lead to reduced lung function. Similarly, a client suffering from seasonal allergies will likely experience worse symptoms if cycling vigorously for several hours when compared to walking at a moderate pace for 30 minutes. Generally speaking, as exercise intensity progresses from moderate to vigorous, the exposure duration for clients should be reduced by 50%.
Common Medication–Exercise Responses and Considerations
The medical management of asthma and/or EIB can include a broad range of medications. Therefore, it is critical that you understand how certain medications interact with an individual’s response to exercise and how the exercise program might need to be adjusted. For example, short- and long-acting beta agonists (i.e., bronchodilators) are commonly prescribed for asthma and/or EIB. These medications help relax and open the airways. However, bronchodilators can also elicit increases in heart rate and blood pressure. As such, additional monitoring of blood pressure may be warranted. Additionally, the use of target heart rate based on age-predicted maximal heart rate is not advised given the potential side effects of asthma and/or EIB control medications.
Clients with asthma are also likely to be taking corticosteroids, which are powerful anti-inflammatory medications used to lessen the severity of exacerbations and provide long-term asthma control. A side effect of corticosteroids is muscle atrophy, so it is important to encourage clients to perform muscular resistance training to help counteract the unwanted muscle-wasting side effects of corticosteroids.
The intent of this section is not to be exhaustive in its scope. Rather, it’s to highlight the concept of medication–exercise responses and reinforce the importance of making appropriate program-design adjustments that better serve your clients who have asthma and/or EIB. It’s also critical to collaborate with medical providers who help your client manage their asthma and/or EIB and familiarize yourself with other relevant medications and considerations for overall exercise programming.
Follow the ACE Integrated Fitness Training Model Guidelines With Special Considerations
Overall, exercise is well tolerated in people with stable asthma and should be encouraged. However, before starting an exercise program, it is prudent for clients with asthma to seek guidance from their physician regarding potential triggers, medication use and what to do if an asthmatic episode occurs during or immediately following exercise. In general, you can use the exercise guidelines presented in Table 1 for cardiorespiratory and muscular training with your clients who have asthma and/or EIB.
Table 1. Exercise Guidelines for Clients With Asthma and EIB
However, there are a number of special programming considerations to keep in mind:
- Clients should have rescue medication with them at all times and be instructed on how to properly use it should symptoms occur.
- Design an exercise program that includes a prolonged warm-up and cool-down and is easily modifiable to match variations in a client’s exercise capacity due to asthma and/or EIB symptoms.
- Clients experiencing worsening of their asthma and/or EIB symptoms should avoid exercise until symptoms have subsided and airway restriction has been relieved.
- Short-acting bronchodilators may be needed, as directed by a physician, prior to and after exercise to prevent and manage asthma and/or EIB.
- Minimize exercise in the presence of airborne allergens and cold environments to help clients avoid bronchoconstriction.
- Clients should be encouraged to initially exercise below the first ventilatory threshold (VT1). Use the talk test to identify your client's personal VT1 values.
- Encourage safe hydration practices before, during and after exercise.
- Aquatic exercise should ideally be performed in non-chlorinated pools, as this decreases the likelihood of asthma events.
- Closely monitor preliminary signs of an asthma attacked and be prepared to respond immediately, possibly by initiating an emergency response sequence. The dyspnea scale (Table 2) can be a helpful guide for monitoring the severity of symptoms.
ACE Certified Professionals have exclusive access to an asthma action plan worksheet, which can be used with clients to help them prevent and control their asthma attacks. This worksheet can be downloaded via the link at the top of this page.
Table 2. The Modified Borg Dyspnea Scale
The ACE Mover MethodTM in Action: Help Clients With Asthma Exercise Safely
The ACE Mover Method was designed to help empower clients to take a personalized journey during which they achieve self-efficacy because the exercise professional or health coach practices empathy and trust, communication and collaboration. Through actionable steps, the ACE Mover Method offers a way for exercise professionals and health coaches to help people move toward a better quality of life.
As a health and exercise professional, you recognize the importance of working closely with your clients, including those who have asthma or EIB, to design and implement safe and effective exercise programs. If you or your clients are uninformed or unprepared, exercise can bring unwelcome negative physiological responses, exacerbations and potentially even more severe health risks.
What are your client’s asthma and/or EIB triggers? What medications are they taking and do they interact with exercise responses? When was your client’s last exacerbation? The ACE Mover Method is a great approach to asking open-ended questions that help your clients better understand their condition and identify how they feel about their preparedness to safely exercise with asthma and/or EIB.
Some clients may be unfamiliar with their individualized triggers. They may not know the cold temperature threshold that is likely to elicit their EIB symptoms. Discuss any barriers that may be preventing your client from feeling comfortable with exercising with their asthma and/or EIB. For instance, maybe they are unsure of how to safely balance the intensity and duration of exercise before it exceeds a threshold that triggers symptoms.
Finally, collaborate and use your knowledge and what they have shared with you to come together and develop the best plan moving forward. Help educate your clients on how to identify their safe cold temperature threshold for exercising outdoors. Collaborate with your clients to perform the talk test to identify their unique VT1 and develop an exercise program that has them working at an intensity below their VT1. There also may be days when allergen levels are too hazardous to safely exercise outdoors. Collaborate with your clients by reviewing the forecast pollen count to make informed decisions.
Working with clients who have specific health challenges such as asthma and/or EIB can be challenging, yet highly gratifying. By understanding the condition and the impact that certain medications may have on exercise response, being mindful of appropriate programming considerations and utilizing the ACE Mover Method, you can set your clients up for success by helping them perform regular exercise safely and effectively while minimizing their asthma and/or EIB symptoms and exacerbations.