Chronic Bronchitis And Physical Activity

What is chronic bronchitis?

Chronic bronchitis, along with emphysema, is the most common condition of chronic obstructive pulmonary disease (COPD). Chronic bronchitis is a long-term inflammation of the airways called bronchi that causes augmented mucus production and other alterations. The main consequence is reduced airflow in the lungs, which impairs breathing. Chronic bronchitis is defined as a productive cough lasting more than 3 months, occurring within a span of two years.² Although bacterial and viral infections usually cause acute bronchitis, the most significant risk factor for chronic bronchitis is exposure to cigarette smoke, either through active smoking or passive inhalation.¹ However, people with a history of respiratory diseases, such as asthma, cystic fibrosis, or bronchiectasis, have a higher predisposition to develop the disease, as do people exposed to environmental pollutants (dust, chemicals) and people with gastroesophageal reflux.^1,2 

Epithelial cells in the airway react to toxic and/or infectious stimuli by releasing inflammatory mediators. This response slowly causes changes in the airway tissue, such as overproduction and hypersecretion of mucus by the goblet cells. During an acute exacerbation of chronic bronchitis, the bronchial mucous membrane has an excess of blood (hyperemia) and fluid (oedema), reducing the bronchial function. This leads to an airflow impediment because of luminal obstruction of the small airways and further leads to frequent lung infections.² 

Symptoms of chronic bronchitis

Most patients with chronic bronchitis typically present a productive cough with sputum (phlegm), and its colour depends on the presence of a secondary bacterial infection. Due to the outcomes described above, they can also present with breathlessness or difficulty breathing and fatigue.³ Fever is uncommon in chronic bronchitis and is suggestive of influenza or pneumonia infection.²

How can exercise improve chronic bronchitis?

Improves respiratory function

Similar to building muscles - you need more oxygen going to the muscles, so the lungs have to work faster and better to deliver oxygen. You might ask if there is any difference when exercising with a condition like this - the answer is yes. With the changes occurring in the lung structure and function, there is a reduced intake of oxygen to peripheral and respiratory muscles among COPD individuals. However, profound changes were observed in these individuals following a structured exercise training program. And here is why: physical activity helps improve muscle function and exercise tolerance.⁴ However, it is important to ensure that patients undergo an adequate assessment of their physical capacity. Those with COPD react to exercise training differently than individuals without this condition.⁵ 

What kind of exercise is recommended for chronic bronchitis?

1. Low-impact aerobics: jogging, swimming, stretching
2. Strengthening exercises: working out with weights

Although people frequently identify bronchitis symptoms as a barrier to exercise, prolonged inactivity is also a significant cause of acute exacerbations.⁴ One of the most prevalent comorbidities of COPD is peripheral muscle dysfunction and weakness. Strengthening exercises contribute to exercise tolerance by reducing symptom intensity and can reverse peripheral muscle dysfunction, at least in part. Strength training has a greater potential to improve muscle mass, provoking less dyspnea during exercise, which most probably makes it easier to tolerate than aerobic training (walking, jogging, biking, etc.).⁵ A physiotherapist will recommend pulmonary rehabilitation with a variety of exercise methods (conventional strength training machines, pulleys, free weights, etc.), and strength training may also be translated into functional performances such as climbing stairs, standing up or arm elevation activities.⁵ Aerobic training also improves peripheral muscle function in patients with COPD. 

However, most patients are unable to sustain high to moderate-intensity exercise because of serious symptoms such as dyspnea and fatigue. So to avoid overloading the cardiorespiratory system, low-impact aerobic exercises could be helpful even when using interval training. COPD patients have improved exercise tolerance by doing low-impact and interval training, with outcomes in quality of life and muscle function, impact on mental health, and reduction of anxiety/depression symptoms.⁵ 

In short, physical activity is helpful for chronic bronchitis patients in non-exacerbation periods. 

Hold off on exercise if you have acute chronic bronchitis

Acute bronchitis is another common type of bronchitis, usually caused by a viral infection (approximately 95%). It can also be caused by bacterial infections, allergens, and physical or chemical irritants (including smoke inhalation, polluted air, and dust). People with chronic bronchitis can also experience episodes of acute bronchitis with worsening symptoms.^6,7 These exacerbations can include productive, persistent, and sometimes purulent cough for 2–4 weeks, malaise (discomfort that is unable to explain by the person), difficulty breathing, and wheezing. Pneumonia can occur during these episodes.⁶ In addition, these individuals received high doses of corticosteroids during these attacks, which reduces the strength of the respiratory muscles. During an episode, the small fraction of oxygen supplied by the compromised airways is required to maintain vital functions. Considering all these, together with the high association of exacerbations with morbidity and mortality, exercises for those in the acute bronchitis period are not advised.⁸

What to look out for when exercising with chronic bronchitis

Preventing exacerbation is a better method for people with chronic bronchitis. A clinician (e.g., physician, nurse, physiotherapist) can help you devise an action plan on how to recognize an episode is a good way to go with the disease. Understanding what proactive steps are needed to gain control of the episode to mitigate the consequences of an exacerbation is another strategy. It has a direct impact on physical activity and reduces overall exercise tolerance and lung function. In particular, recognising sudden symptoms during exercise, such as dizziness, shortness of breath, or feeling disoriented, could be helpful.⁹ Acute bronchitis is a medical emergency, and a doctor needs to be called immediately. 

Conclusion

Chronic bronchitis is a COPD condition. The main symptom of chronic bronchitis is a productive, persistent and purulent cough. Exercise can improve comorbidities associated with chronic bronchitis, and different modalities can be recommended by clinicians depending on the severity and health condition. The benefits are related to lung function and muscle strengthening but also to the quality of life and mental health. However, acute bronchitis episodes are not favourable for physical activity, which can lead to the development of serious symptoms such as breathlessness and fatigue.