Thus, ensuring that there is a large, uninterrupted flow of air into the lungs is an important factor in determining ones ability to sustain a high level of aerobic work. Sounds simple enough, but the truth is that the method by which the lungs fill with air is quite relevant to the efficiency of the process. In order for the lungs to fill there must be negative pressure created within the lungs. This pressure differential between the chest and outside atmosphere then causes air to flow into the lungs. The shoulders and collarbone are raised while the abdomen is contracted during inhalation.
Maximum effort is made, but a minimum amount of air is obtained.
Thoracic breathing is done with the rib muscles expanding the rib cage, and is the second type of incomplete breathing. Deep abdominal breathing is the best, for it brings air to the lowest and largest part of the lungs. In order to get the most oxygen-rich air into the lungs everyone should learn proper diaphragmatic breathing. Place a hand on your upper abdomen, where the diaphragm is located. Breathe in and out slowly.