Aerobic conditioning

Aerobic conditioning is usually achieved through aerobic exercise such as running, swimming, rowing machine, elliptical, treadmill, cycling, etc. A stronger heart does not pump more blood by beating faster but by beating more efficiently, primarily via increased stroke volume and left ventricular mass. Trained endurance athletes can have resting heart rates as low as a reported 28 beats per minute (Miguel Indurain) or 32 beats per minute (Lance Armstrong), both of whom were professional cyclists at the highest level.

Aerobic conditioning makes the heart and lungs pump blood more efficiently, delivering more oxygen to muscles and organs. Skeletal muscles also become aerobically conditioned, as regular aerobic exercise produces a shift in muscle fibres from more type II (fast twitch/glycolytic) into more type I (slow-twitch/oxidative). Type I muscle fibres have far more mitochondria than type II, making type I fibres the producers of adenosine triphosphate (ATP) primarily through oxidative phosphorylation rather than anaerobic glycolysis.

Some neuromuscular diseases recommend regular aerobic exercise (of varying intensities depending on the disease) in order for the skeletal muscles to become aerobically conditioned, providing symptom relief or slowing the course of the disease, for example metabolic myopathies, Duchenne muscular dystrophy, and idiopathic inflammatory myopathies (IIM).

History

Both the term and the specific exercise method were developed by Dr Kenneth H. Cooper, an exercise physiologist, and Col. Pauline Potts, a physical therapist, both of the United States Air Force. Cooper, an exercise enthusiast, was puzzled about why some people with good muscular strength were prone to perform poorly at activities such as long-distance running, swimming, and bicycling. He began using a bicycle ergometer to measure sustained performance in terms of a person's ability to use oxygen. In 1968, he published Aerobics, which included exercise programs using running, walking, swimming and bicycling. At the time the book was published there was increasing awareness of the need for increased exercise due to widespread weakness and inactivity. Cooper published a mass-market version The New Aerobics in 1979.

Aerobic dancing was invented by Jacki Sorensen in 1969, inspired by Cooper's book. Sorensen began teaching her method and spreading it throughout the U.S. in the hands of hundreds of instructors in the 1970s. At the same time, Judi Missett's Jazzercise was taking off in the form of dance studio franchises in the U.S. Aerobics gained greater popularity, spreading worldwide after the release of Jane Fonda's Workout video in 1982, sparking an industry boom.