Breathlessness
Shortness of breath during exercice is a very common symptom that can be related to many situations, and will often require a consultation with your doctor to rule out a pathology (disease).
Your doctor could speak of “dyspnea”, the medical term for a sensation of difficulty in breathing.
Mechanism
When you exercise, your muscles need oxygen (O2). This oxygen is supplied by the blood. It binds to hemoglobin, a protein found in red blood cells, and, on contact with the muscle, is transmitted to the muscle fiber. Here, oxygen helps to generate the energy needed for contraction by “burning” sugars and fats. This operation results in the production of carbon dioxide (CO2).
As effort increases, so does oxygen need and carbon dioxide production. Carbon dioxide stimulates pulmonary ventilation, so that alveolar exchanges increase and more oxygen is inspired.
At the same time, cardiac output also increases to deliver “more” O2 with each beat. This flow increases by increasing the amount of blood ejected with each beat, and by increasing the number of beats per minute (heart rate).
To sum up,when you exercice, your heart speeds up and so does your respiratory rate. At high respiratory rates, you may feel out of breath. When the effort is maximal, shortness of breath is perfectly normal!
How to breathe to avoid being out of breath?
At home or on easy exercices, entraînez-vous à inspirer en gonflant le ventre pour favoriser la descente du diaphragme et augmenter le volume libre dans la cage thoracique.
Once automatic, this breathing technique allows you to inhale a greater quantity of oxygen during exercise.
This article is part of a series of articles about breathing and breathlessness. Visit here for other articles.