Breathing is a necessary function of life, and most of the time it is effortless. However, if you exercise regularly, you may think about breathing more often. That’s because the respiratory muscles can fatigue just like any other skeletal muscle.
Interestingly, the lungs have no skeletal muscles of their own. The work of breathing is done by the diaphragm, the muscles between the ribs (intercostal muscles), the muscles in the neck, and the abdominal muscles. The diaphragm, a dome-shaped sheet of muscle that separates the chest cavity from the abdomen, is the most important muscle used for breathing in (called inhalation or inspiration). The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine. As the diaphragm contracts, it increases the length and diameter of the chest cavity and thus expands the lungs. The intercostal muscles help move the rib cage and thus assist in breathing.
We breathe in, we breathe out, every minute of every day. That’s because breathing is under autonomic nerve control. The signals are sent from the brain automatically. The brain determines when we need to breathe based on the signals it receives from our organs and nerves. Although we can breathe in and out on command – for example, during pulmonary function testing or when completing breathing exercises – respiratory muscle function is primarily an automatic task.
The process of breathing out (called exhalation or expiration) is usually passive when a person is not exercising. The elasticity of the lungs and chest wall, which are actively stretched during inhalation, causes them to return to their resting shape and to expel air out of the lungs when inspiratory muscles are relaxed. Therefore, when a person is at rest, no effort is needed to breathe out. During vigorous exercise, however, a number of muscles pa
rticipate in exhalation. The abdominal muscles are the most important of these. Abdominal muscles contract, raise abdominal pressure, and push a relaxed diaphragm against the lungs, causing air to be pushed out.
We don’t often think of strengthening these respiratory muscles or about how important they are. Learn more so you can keep these important muscles strong and helping you be the healthiest you that you can be!
Contact Dr. Shawn Tsuda if you or a loved one is interested in learning about ways to treat obesity and the metabolic disorders that come along with it. He and his team of experts can help you.