Information AboutSwimming |
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''This article concentrates on human swimming. For other species, see Ability To Swim .'' Swimming is the movement used in Water without artificial assistance. swimmer]] =History= Drawings from the Stone Age were found in "the cave of swimmers" near Sura, dating back to 2000 B.C. In 1538 Nicolas Wynman, German professor of languages, wrote the first swimming book. Competitive swimming in Europe started around 1800, mostly using breaststroke. The front crawl, then called the ''trudgen'' (now known prodominantly as freestyle) was introduced in 1873 by John Arthur Trudgen, copying it from Native Americans. Swimming was part of the first modern games 1896 Summer Olympics Games in Athens. In 1900 backstroke was included as an Olympic Event. In 1908, the world swimming association Federation Internationale de Natation was formed. Butterfly was first a variant of Breaststroke, until it was accepted as a separate style in 1952 TECHNIQUE The Human Body is 70% water and has a very similar density to water. While the Lung s are filled with the Air , the body is slightly less dense than the surrounding water, and there is a net upward force on the body. Thus staying afloat requires only a slight propelling of water downward relative to the body, and transverse motion only a slight propelling of water in a direction opposite to the direction of intended motion. This propelling is accomplished by using the hands and forearms as Paddle s, and by kicking the legs and feet to push water away from the body (though kicking accounts for relatively little thrust). Since salt water (e.g. the ocean) is denser than fresh water (e.g. most swimming pools), less effort is required to stay afloat in salt water than in fresh water Swimming Styles have been developed based on the following principles: The torso and the legs should be kept as parallel as possible to the surface of the water. Dropped legs or a slanted torso dramatically increase drag. The hand should be extended forward of the head as much as possible. This increases the avrage length at the water-line, substantially increasing speed Recent research has shown that hand force applied to the water is generated by the rotation of the hips, and not by the muscles of the arm. The muscles that pull the arm through the water are attached within one inch of the top of the arm. With a 21" arm, the lever ratio is 1:20, which means that a 100 lbs. of pull by the shoulder muscles produces only 5 lbs. of force at the hand as it pushes back against the water. The torque generated by the larger, stronger hip muscles, on the other hand, whips the hands through the water, much like golfers or batters whip their clubs and bats through the air with a fast turn of the hips. Elite swimmers who were able to make modest increases in the acceleration of their hips doubled their peak hand force output The time spent on the side should be maximized so the shoulders do not break the water-line and do not produce Bow Waves . This reduces the frontal cross-section, reducing drag further, and also increasing the ratio between the body's water-line-length and width. Similar improvements are possible by orienting the narrowest direction of head, hands, legs and arms into the water. The torso is by far the most critical. The motion of the Hand , arm, and leg from the back to the front should be in the air for as much time during the recovery stroke as possible, and in the water, oriented as hydrodynamically as possible, because the returning appendage has to move at least twice as fast as the swimmer, and in the water generates eight times the drag (which increases with the cube of the speed) of an equal amount of torso frontal area. Rotating the shoulders also adds power to the pull by using Abdominal Muscles to help pull the arm through the water The basic "catch" of the water is not nearly as critical as the above items. Most swimmers simply grab water with their hand flat, or the fingers slightly spread, and then draw it smoothly down their body. None of the above techniques require improved strength. With strength training, the hands and feet can be extended further into the water, gaining more propulsion. For beginners, increased strength brings only small improvements if the above strategies (minimising drag and lengthening water-line) are not optimal. Another technique that can help an athlete swim at a higher performance level is proper breathing techniques. Breathing correctly can make the swimmer swim faster and with less fatigue. Competitive swimmers take in one breath and gradually let it out over three to four strokes. As the race progresses and the swimmer becomes tired, less oxygen from those breaths reach the muscles. It is possible to teach the body to run on less than normal levels of oxygen. Take a deep breath at one side of a pool, submerge fully, and kick like a dolphin. Try crossing the pool with one breath, and then extend the distance. Another way to practice endurance is by taking a breath and letting it out over six strokes (while freestyle swimming). Skeletal Animation and Computational Fluid Dynamics allow simulation of swimmers. This allows the forces on joints and muscles to be measured, and, if multiple simulations are employed, to compare different styles or individuals. By means of Computer Graphics or Motion Capture the simulation can be compared to real swimmers. References with images: {Link without Title} , {Link without Title} , {Link without Title} , {Link without Title} Fluent, Inc. : {Link without Title} , [http://www.fluent.com/about/news/newsletters/04v13i1/a1.htm COMPETITIVE SWIMMING The goal of competitive swimming is to be the fastest to swim a given distance. Competitive swimming became popular in the nineteenth century, and comprises 34 events - 17 male events and 17 female events. Swimming is a popular event at the Summer Olympic Games , where male and female athletes compete in 13 of the recognized events each. Olympic events are held in a 50 Meter pool. Competitive swimming's international governing body is FINA (Fédération Internationale de Natation), the ''International Swimming Federation''. .]] The four competitive strokes are the Butterfly , Backstroke , Breaststroke , and Freestyle (front crawl). While "freestyle" and "front crawl" are often used interchangeably, a swimmer may actually swim any stroke in a freestyle race as long as it is done continuously throughout the whole race. Swimmers generally choose to swim the front crawl in a freestyle event since the front crawl is typically the fastest stroke. These strokes can be swum individually or together in an s or Yard s, 400 meters or yards, and 800 meters or yards (which is only swum freestyle). In a 50 meter pool, each swimmer swims one length for the 200 relay, two lengths for the 400 relay, and four lengths for the 800 relay. In a 25 meter or yard pool, each swimmer swims two lengths for the 200 relay, four lengths for the 400 relay, and eight lengths for the 800 relay. Many full-size competition pools in the United States have a length of 50 meters and a width of 25 yards (the Olympic pool size, allowing both short course (25 m or 25 Yd pool) and long course (50 m pool) races to be held. There are several types of judges: a starter sets off the swimmers; turn judges check that the swimmers' turns are within rules; swim judges check the swimmers' strokes; time keepers time the swims; and the referee checks that everything is running smoothly. If an Official catches a swimmer breaking a rule concerning the stroke he or she is swimming, that swimmer is said to be disqualified (commonly referred to as "DQ'd" or "deaked") and the swim is not considered valid. In the United States and the United Kingdom, communities may sponsor competitive swimming leagues for children and teenagers, made up of swim teams. These leagues for the most part adhere to recognized swimming rules, swim the standard strokes, but swim shorter lengths as events in swim meets. These leagues are usually active in the warmer months, and are not directly associated with a national or world swim organization. However, swimmers who begin their competitive swimming experience on such a local swim team may go on to join a nationally-governed team. In Australia such competition is usually conducted under the auspices of a club affiliated with the State Association which in turn is affiliated with Swimming Australia, the FINA accredited body. This provides a direct pathway to top level competition for those capable of taking it while still providing a more relaxed environment for those whose main intent is to have fun swimming competitively. :''See also List Of Swimmers RECREATIONAL SWIMMING The most common purpose for swimming is recreation. Recreational swimming is considered by many a good way to relax, while enjoying a good full-body workout. Several Swimming Styles are suitable for recreational swimming; most recreational swimmers prefer a style that keeps their head out of the water and has an underwater arm recovery. Breaststroke , Side Stroke , and Dog Paddle , are the most common strokes utilized in recreational swimming, but the out-of-water arm recovery of freestyle or butterfly gives rise to better exploitation of the difference in resistance between air and water. swimmer]] The butterfly stroke, which consists of out-of-water recovery with even symmetry in body movements, is most suited to rough water swimming. For example, in a record-setting example of endurance swimming, Vicki Keith crossed the rough waters of Lake Ontario using butterfly. Most recreational swimming takes place in pools, and calm natural waters (sea, lakes, rivers). Therefore freestyle (which does not work as well in rough water) is suitable. OCCUPATIONAL SWIMMING Some occupations require the workers to swim. For example, Abalone divers or Pearl divers swim and dive to obtain an economic benefit, as do Spear Fishermen . Swimming is used to rescue other swimmers in distress. There are a number of specialized swimming styles specially for rescue purposes (''see List Of Swimming Styles ''). Such techniques are studied by Lifeguard s or members of the Coast Guard . The training of these techniques has also evolved into competitions such as Surf Lifesaving . Swimming is also used in Marine Biology to observe plants and animals in their natural habitat. Other sciences use swimming, for example Konrad Lorenz swam with Geese as part of his studies of Animal Behavior . Swimming also has Military purposes. Military swimming is usually done by Special Forces , such as Navy SEALS . Swimming is used to approach a location, gather intelligence, sabotage or combat, and to depart a location. This may also include airborne insertion into water or exiting a Submarine while it's submerged. Swimming has become a professional sport as well. Companies such as Speedo , TYR Sports and Nike sponsor swimmers who are at the international level. Cash awards are also given at many of the major competitions for breaking records. OCEAN SWIMMING See main article Ocean Swimming Ocean swimming is the sport of swimming and racing in the sea. SWIMMING FOR EXERCISE Swimming is an excellent form of Exercise . Because the Density of the human body is approximately similar to that of Water , the body is supported by the water and less stress is therefore placed on joints and bones. Therefore, swimming is frequently used as an exercise in rehabilitation after injuries or for those with Disabilities . Resistance Swimming is one form of swimming exercise. It is done either for training purposes, to hold the swimmer in place for stroke analysis, or to enable swimming in a confined space for athletic or therapeutic reasons. Resistance swimming can be done either against a stream of moving water (often termed a '' Swimming Machine '') or by holding the swimmer stationary with elastic attachments. Swimming is primarily an Aerobic Exercise due to the long exercise time, requiring a constant Oxygen supply to the muscles, except for short sprints where the muscles work Anaerobically . As with most aerobic exercise it is believed to reduce the harmful effects of Stress . Swimming can improve Posture and develop a strong lean Physique , called, logically, a "swimmer's build:" lean and spare throughout, with wide shoulders and a smaller lower body. THE RISKS OF SWIMMING Beach.]] Swimming is generally a healthy activity and enjoys a low risk of injury compared with many other sports. Nevertheless there are some health risks with swimming, including the following:
SWIMMING LESSONS |
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