Chronic Respiratory Diseases and Exercise
Chronic lung diseases
Chronic lung diseases include:
- Chronic bronchitis: a common chronic disease affecting mostly airways and alveoli, especially in smokers, and characterized by increased mucus production.
- Emphysema: a lung condition that is part of chronic obstructive pulmonary disease. It has genetic causes and can be worsened or brought on by smoking.
- obstructive bronchitis
- cystic fibrosis.
The main characteristic of these diseases is the expiratory flow reduction for a long time.
Smoking, air pollution and inhalation of other irritants, as well as frequent airway infections, lead to hypertrophy of the bronchial tree glands, increased secreted mucus, reduced mobility of the protective fringes of the bronchial tree, and hypertrophy of the mucosa of the bronchial wall.
In the long run, these morphological disorders lead to obstruction of the bronchial lumen, which is particularly aggravated during a respiratory infection, and to pulmonary emphysema, i.e. to permanent severe damage to the cell wall, which loses its elasticity.
Chronic bronchitis characteristics are:
- cough (lasting more than 3 months a year, the last two years),
- shortness of breath (especially with fatigue) and
- easy infection of the respiratory system by infections.
In chronic clinical form of the disease, bronchial obstruction is observed throughout the year. Moreover, it has been observed infiltration of inflammation in the bronchioles. Bronchial Asthma Airway obstruction is also observed in bronchial asthma, in which episodes of exacerbated dyspnea occur, mainly due to a partial temporary obstruction (spasm) of the airways, which mainly impedes the function of exhalation.
Bronchial asthma is usually the result of bronchial hyperresponsiveness and allergic reaction in the body. Airway disorders during a bronchial asthma episode are the cause of spasm of the smooth muscle fibers of the bronchi (due to the release of certain substances, such as histamine, and / or stimulation of nerve endings), local swelling in the mucosa and hypersecretion of mucus from its glands.
Interstitial lung diseases include more than 300 diseases, with the most common being idiopathic pulmonary fibrosis and sarcoidosis. Pneumoconiosis, pulmonary vasculitis and collagen diseases are also classified as diffuse interstitial lung diseases. These are characterized by inflammatory infiltration and fibrosis of the interstitial lung tissue and alveoli, which lead mainly to significant problems in the diffusion of gases.
Most patients show reduced pulmonary ventilation, as well as reduced vital and total pulmonary capacity and gas diffusion capacity and for these reasons show severe shortness of breath. Only sarcoidosis and histiocytosis X do not cause dyspnea. Pulmonary circulation diseases include those that affect the pulmonary circulation, such as pulmonary embolism and primary and/or chronic pulmonary hypertension. Pulmonary circulatory disorders cause serious problems with oxygenation of the arterial blood and lead to significant hypoxemia during exercise.
Since the therapeutic role of regular exercise in patients with obstructive pulmonary disease has been proved, from 2000 onwards therapeutic exercise programs were introduced in patients with diffuse interstitial lung disease, mainly pulmonary fibrosis and sarcoidosis, as well as pneumonia.
Exercise in patients with chronic lung disease
In Sports Medicine Laboratory of Aristotle University of Thessaloniki, therapeutic exercise programs are implemented for patients with pulmonary hypertension, as well as for children with cystic fibrosis, in collaboration with the University Clinics of the Medical School of the Aristotle University of Thessaloniki. Rehabilitation programs are also implemented for patients with mild or moderate pulmonary dysfunction. They are individualized and lead to an increase in the degree of tolerance to muscular effort and to the improvement of the ability to perform physical work.
Their aim is to enable these patients to perform adequately the activities of their daily lives, without obvious shortness of breath. This can be achieved mainly by increasing trophicity and improving the function of the respiratory muscles. At the same time, the function of the other working muscles is improved, resulting the reduction in oxygen consumption.
People with chronic bronchopneumonia have limited ability to perform physical exertion, even low-intensity exercise, when there is moderate or severe respiratory failure.
A characteristic clinical finding that leads to rapid cessation of exercise in chronic lung disease is the feeling of shortness of breath.
Causes that lead to worsening of shortness of breath during exercise are:
- the reduction of the maximum expiratory flow,
- the increase of the functional residual capacity, due to the decrease of the elasticity of the lungs,
- the reduction of trophicity and strength of the respiratory muscles,
- the reduction of the diffusion capacity of the lungs,
- the occurrence of secondary pulmonary hypertension and
- the hyperventilation.
Patients also interrupt physical activity early, due to peripheral fatigue.
Regular exercise in these patients has not a therapeutic meaning, but improves their ability to produce physical work. It is recommended to avoid exercise at high altitudes (greater than 800-1000 m), as well as when bad weather conditions prevail (low or high temperature, high humidity index).
Type, intensity, duration and frequency of exercise depend on the disease, the degree of patients’ respiratory function and their physical adequacy.
Therefore, before their inclusion in exercise programs, it is necessary to evaluate their functional capacity. The 6-minute walking test is a simple field test, which assesses patients' ability to exercise, as it assesses the distance, they can cover in 6 minutes. In respiratory patients it is performed with concomitant oximetry, to check the oxygen saturation during the test.
In the initial phase, sessions with low-intensity aerobic exercises are performed, such as simple walking, climbing stairs, and cycling at low intensities, lasting at least 30 minutes, 5 times per week.
At the same time, intermittent exercises of the upper extremities should be applied, to increase the endurance and strength of the muscles. Simple exercises aim at improving joint flexibility and muscle stretching. Breathing exercises are also applied.
At the same time, patients are trained in more economical and efficient breathing techniques. Breathing exercises aim at improving the functional capacity of the diaphragm and other respiratory muscles.
It is also recommended to apply strengthening exercises at least 2 times a week, with low intensity to moderate intensity, about 70% of 1 maximum repetition (RM), in 2-3 sets of 8-12 repetitions.
Over time, as patients’ ability to perform muscle work improves, the intensity and duration of exercise gradually increases, with more and more difficult exercises being done. The effort of patients suffering from moderate or severe hypoxemia can be facilitated by inhaling oxygen before or during exercise.
Exercise programs should last at least 6 months, but lifelong exercise and an active lifestyle are also recommended.
How exercise helps?
Regular exercise mainly improves patients’ ability to work, as function of the skeletal muscles of the limbs is been improved. It also reduces the feeling of shortness of breath as well as the fatigue of respiratory muscles, with the favorable effect it causes on the functional characteristics of the lung and on the respiratory muscles work.
Regarding the effects of regular exercise on respiratory function, it seems that training leads to an increase in pulmonary ventilation and the diffusion capacity of gases, i.e. the ability to exchange O 2 and CO 2 between the pulmonary cells and the blood capillaries that surround them.
Furthermore, with regular exercise the respiratory muscles (intercostal muscles, diaphragm, abdominal muscles) make better use of oxygen. Thus, a specific task requires less oxygen for the function of these muscles in the trained respiratory patients compared to the untrained ones.
The respiratory muscles of people with increased physical activity need less oxygen for their work, compared to people who do not exercise, because training increases the elasticity of tissues in the lungs and chest wall.
The benefits of exercise in the psychological field are also important, as it reduces anxiety and depression, increases self-confidence and improves the quality of life of patients.