Aerobic activity is defined by Wikipedia as “physical exercise that intends to improve the oxygen system and refers to the use of oxygen in the body’s metabolic or energy-generating process.” The ability to absorb oxygen is what it’s all about. The body of a well-conditioned person absorbs oxygen much more efficiently than the body of an inactive person.
The lungs of a normal-sized adult carry about 300 million tiny, microscopic sacks called alveoli. The walls of these sacks are only one cell thick and are each covered with a mesh of blood vessels. When the lungs fill with air the oxygen flows through the sack walls into the blood vessels and enters the blood stream. These 300 million microscopic alveoli have a combined surface area of about 150 square meters (about the size of a tennis court) through which the oxygen is absorbed.
The problem is that nobody can use all of his 300 million alveoli when he breathes. Everyone has a certain portion of his lungs which can never expel the air that is in them. The portion of the lungs which always retains its air is called “residual volume,” and its purpose is to keep the lungs from collapsing. The portion of the lungs that is useful for breathing is called the “vital capacity.” In an unconditioned body, a much smaller portion of the lungs is vital capacity and the residual volume is much larger than what it needs to be. As a body becomes conditioned with regular aerobic activity, the vital lung capacity increases substantially. In a well conditioned body the vital lung capacity will be about 75%.
A body needs aerobic exercise to prepare it for the maximum stress that it will face. When a person is at rest his body expends very little energy and requires a relatively small supply of oxygen. But when a person exerts himself, his body may demand as much as 20 times the oxygen that it needs when the body is at rest. If the lungs are not capable of delivering the oxygen supply that the body needs, the heart may suffer serious damage or complete failure as it over works itself in an attempt to compensate for inadequate vital lung capacity.
The lungs have no muscles of their own. They depend on the surrounding muscles to inflate them as the diaphragm lowers and the rib cage expands. As a person conditions himself with regular aerobic exercise, these muscles become toned and acquire more tissue to make them stronger. Regular aerobic activity also programs the breathing muscles to work much faster. It is an experimental fact. An unconditioned person will normally be able to breathe about 10 times his vital capacity in one minute. After just six weeks of substantial aerobic activity, that same person will be able to breath 20 times his vital lung capacity in one minute.
Mark Roof has experienced first hand the changes that aerobic activity has made in his own life, and he is eager to share the benefits with the world. There is more on the subject of Cardio Aerobic Training for healthy heart, lungs, and blood vessels. Or, if you want the whole story, please visit aerobicexcellence.com
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