Exercise Intolerance
Not everyone has the stamina of a marathon runner. In fact, the majority of us are probably not as fit as we’d like to be. We’re just “out-of-shape”, however there are some people who have a medical illness that limits their ability to exercise. This is called exercise intolerance. More on exercise can be found HERE.
VO2 max represents the level of fitness and is impaired by disease states that contribute to exercise intolerance (red).
Exercise intolerance occurs from an inability to get oxygen into the blood because of an abnormality in the gas-exchange areas of the lungs (alveoli), an inability of our hearts to pump enough blood or a combination of the two. Some medical conditions, such as respiratory infections, are temporary and not necessarily considered under the category of “exercise intolerance” but can impact one’s ability to exercise during the acute illness. These will not be discussed here.
Deoxygenated blood returns to the right side of the heart where it is pumped to the lungs through the pulmonary arteries (blue). The pulmonary arteries receive oxygen from the alveoli (gas exchange units) of the lungs and then return to the left side of the heart through the pulmonary veins (red). This oxygenated blood is then pumped from the left side of the heart out to the body through the aorta. Diseases of the pulmonary arteries, the gas exchange units (alveoli and small blood vessels), the pulmonary veins or the heart itself can lead to exercise intolerance. Cartoons drawn by the BreathingNYC team.
Exercise Induced Asthma or Cough
Exercise is a common trigger for asthmatics and can be a source of a nagging cough in non-asthmatics. The process of rapid and deep breathing can both dry out the airways stimulating cough or can bring in lots of pollen, pollution, smoke or other inflammatory triggers. There are strategies to combat against exercise induced asthma that your pediatrician or pediatric pulmonologist can help with. Click HERE to learn more.
Exercise Induced Laryngeal Obstruction (Vocal Cord Dysfunction)
Exercise can frequently be associated with abnormal movement of the vocal cords which can cause a cough or stridor (a loud or sharp sound during breathing). This can be really frightening for the athlete and can be a source of significant exercise disruption or intolerance. It typically does not respond to asthma medications (inhalers) and can be quite challenging to diagnose. Consult your pediatric pulmonologist if you think you might have exercise induced laryngeal obstruction (EILO). Additional information on EILO can be found HERE.
Cystic Fibrosis or Bronchiectasis
Children with cystic fibrosis or idiopathic bronchiectasis can have significant impairments in their lung function. This can inhibit the lungs’ ability to bring oxygen into the blood, making it challenging for the child to exercise. For more on cystic fibrosis, click HERE.
Heart Disease
There are several types of heart disease that can lead to exercise intolerance. The common feature is that the heart isn’t effectively pumping blood to the lungs. This can occur in various types of heart failure or arrhythmia (abnormal heart beats). Consult your pediatrician or pediatric cardiologist if you are worried that your child has a heart condition contributing to exercise intolerance.
Pulmonary Hypertension
Pulmonary hypertension is a broad category of conditions that includes disorders of the pulmonary arteries, disorders of the pulmonary veins and any condition that leads to a high blood pressure in the pulmonary circulation. This can include heart, lung or blood clotting diseases. Chronic high blood pressure in the lung circulation can challenge the heart and eventually lead to heart failure. Pulmonary hypertension is a rare but serious condition and exercise intolerance is often the first symptom. It occurs because the heart can not pump enough blood through the lungs to keep up with the amount of oxygen the body is demanding during exercise. For more on pulmonary hypertension, click HERE.