The word "aerobic" means "using oxygen." Aerobic exercises are those designed to increase the oxygen content in the blood and pump this oxygen-enriched blood to the muscles, increasing overall health. Aerobic exercise involves performing an active movement, such as jogging (see entry under 1970s— Sports and Games in volume 4), biking, or swimming, for an extended period of time. This sustained movement allows the heartbeat to increase and remain at a high level.

When the benefits of prolonged energetic physical activity were first publicized in 1968, only about one hundred thousand Americans jogged for exercise. By 1999, over thirty-four million American were running regularly. Millions more rode stationary bikes or attended classes for aerobics, aerobic dance, jazz (see entry under 1900s—Music in volume 1) aerobics, aqua aerobics, step aerobics, and more.

In 1968, Kenneth H. Cooper (1931–), an Air Force surgeon from Dallas, Texas, published a revolutionary new exercise book based on his...