Swimming is a competitive and recreational activity consisting of various motions that propel the body through the water. Swimming is considered by most experts to be one of the best forms of physical exercise. When practiced properly the activity utilizes most of the body's muscles and is an excellent conditioner for the cardiovascular system. Much of the wear and tear on the human body that is sometimes associated with land sports, such as running, is reduced in swimming because of the body's buoyancy in water. Physical rehabil-itation therapy involving swimming is not uncommon. International competition in swimmingas well as in its sister activity, DIVINGis governed by the Federation Internationale de Natation Amateur (FINA). Swimming has been part of the Olympics since its modern-day inception in 1896.A variety of strokes is used in swimming, each requiring different motions. Each also varies in the physical demand placed on the swimmer and degree of speed and efficiency offered. Crawl. The crawl is not an official FINA-recognized stroke; in events where the contestants are allowed to swim "freestyle," the crawl is universally used. The stroke, which is performed chest-down in the water, involves carrying one arm forward out of the water to nearly full extension, while the other arm is below the surface making a pulling movement that propels the body through the water. The flutter kick is used to add some forward thrust, but it serves mainly as a stabilizing motion. Breathing is accomplished by turning the head to one side or the other and inhaling, then turning the head so that the face is immersed and exhaling the spent air. The breathing is repeated at regular intervals in accord with the pace of the stroke.Backstroke. The backstroke is similar to the crawl but is performed on the back and without the crawl's breathing requirement. One arm is carried over the head out of the water to prepare for the next stroke, w...
