As a respiratory physiologist, I can explain that intercostal breathing is a type of respiratory movement that involves the intercostal muscles, which are located between the ribs. These muscles play a crucial role in the process of inhalation and exhalation. During inhalation, the intercostal muscles contract, causing the rib cage to expand both outward and upward. This expansion increases the volume of the chest cavity, which in turn creates a vacuum that draws air into the lungs. The diaphragm, a dome-shaped muscle that separates the chest from the abdomen, also contracts and moves downward, further increasing the thoracic volume and facilitating the intake of air. Conversely, during exhalation, the intercostal muscles relax, allowing the rib cage to return to its resting position. The diaphragm also relaxes and moves upward, reducing the volume of the chest cavity and pushing air out of the lungs. Intercostal breathing is particularly important during periods of increased oxygen demand, such as during exercise or when experiencing respiratory distress. It is a more efficient form of breathing that can help to maximize oxygen intake and carbon dioxide removal. read more >>

When you breathe in air, they normally contract and move your ribs up. At the same time, your diaphragm, which is a thin muscle that separates your chest and abdomen, drops lower and your lungs fill with air. ... As a result, your intercostal muscles pull sharply inward.read more >>