ebooksgratis.com

See also ebooksgratis.com: no banners, no cookies, totally FREE.

CLASSICISTRANIERI HOME PAGE - YOUTUBE CHANNEL
Privacy Policy Cookie Policy Terms and Conditions
Swimming - Wikipedia, the free encyclopedia

Swimming

From Wikipedia, the free encyclopedia

Swimming is the movement by humans or animals through water, usually without artificial assistance. Swimming is an activity that can be both useful and recreational. Its primary uses are bathing, cooling, travel, fishing, escape, and sport.

Animals with lungs have an easier time floating than those without.[1] Almost all mammals can swim by instinct, including bats, kangaroos, moles and sloths. The few exceptions include apes and possibly giraffes and porcupines. There are several reports of apes in zoos falling and drowning in water moats without any struggle (see Bender 1999: 114-119).[citation needed] However, some apes can learn swimming: there is a report of two gorillas swimming in a zoo (Bender 1999: 116-117) and of some orangutans of the Kaja Islands who have learned to swim (Schuster, Smits & Ullal 2008: 102). Land birds can swim or float for at least some time. Ostriches, cassowaries and tortoises can swim. Juvenile penguins drown if they accidentally fall in water since their down cover is not designed for aquatic activities.

Contents

[edit] Non-aquatic animals

Humans do not swim instinctively, but they feel attracted to water and show a broader range of swimming movements than other non-aquatic animals (Bender 1999: 119-169). In contrast, many monkeys can naturally swim and some, like the proboscis monkey, crab-eating macaque, and Rhesus macaque swim regularly.

A dog swimming
A dog swimming

Some breeds of dog swim recreationally. Umbra, a world record-holding dog, can swim 4 miles (6.4 km) in 73 minutes, placing her in the top 25% in human long-distance swimming competitions[2]. Although most cats hate water, adult cats are good swimmers. The fishing cat is one wild species of cat that has evolved special adaptations for an aquatic or semi-aquatic lifestyle - webbed digits. Tigers and some individual jaguars are the only big cats known go into water readily, though other big cats, including lions, have been observed swimming. A few domestic cat breeds also like swimming, such as the Turkish Van. In a unpublished research carried out 2002 at the University of Bern (Switzerland) , Bender & Hirt showed that the Turkish Van has less inhibition to enter in shallow water compared to another breed, the Russian Blue. This behavior can be partially explained by the character of the Turkish Van, who seems to be more curious and enterprising than other cat breeds (see Widmer 1990).

Horses, moose, and elk are very powerful swimmers, and can travel long distances in the water. Elephants are also capable of swimming, even in deep waters. Eyewitnesses have confirmed that camels, including Dromedaries and Bactrians, can swim[3], despite the fact that there is little deep water in their natural habitats.

Both domestic and wild rabbits can swim. Domestic rabbits are sometimes trained to swim as a circus attraction. A wild rabbit famously swam in an apparent attack on U.S. President Jimmy Carter's boat when it was threatened in its natural habitat.[4]

The Guinea pig (or cavy) is noted as having an excellent swimming ability.[5]. Mice can swim quite well. They do panic when placed in water, but many lab mice are used in the Morris water maze, a test to measure learning. When mice swim, they use their tails like flagella and kick with their legs.

Many species of snakes are aquatic and live their entire lives in the water, but all terrestrial snakes are excellent swimmers as well.[citation needed] The larger pythons and anacondas spend the majority of their time in the water; their skeletons are not able to support their body weight well on dry land. Many Beetles are able to swim, some species of diving beetle spend most of their time in the water.

[edit] Competitive swimming

The goal of competitive swimming is to be the fastest over a given distance. Competitive swimming became popular in the nineteenth century, and comprises 34 individual events - 17 male events and 17 female events. Swimming is an 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, freestyle is the more common name and is used in almost all competitive, club-swimming or international competitions.Swimmers generally choose to swim front crawl in a freestyle event since it is the fastest and easiest stroke. Disqualification will occur if the stroke is not swum correctly, for example if the swimmer does not touch the wall with two hands during breaststroke or butterfly.

These strokes can be swum individually or together in an individual medley (IM). The IM order is: 1) butterfly, 2) backstroke, 3) breaststroke, and 4) freestyle. There are two types of relays: medley and freestyle. The medley relay order is: 1) backstroke, 2) breaststroke, 3) butterfly, and 4) freestyle. Each of the four swimmers in the relay swims a predetermined distance, dependent on the overall length of the relay. The three relay lengths are 200 meters or yards, 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.There have also been 100 yard relays that have been done by 8 and under swimmers, but is very rare except in summer recreation leagues. 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 sends the swimmers off the blocks and may also call a false-start if a swimmer leaves the block before the starter sends them; finish judges make sure the swimmers touch the wall with the appropriate number of hands (one hand for freestyle and backstroke, two for breaststroke and butterfly with the swimmer's hands touching the wall at the same time, not one after another) turn judges check that the swimmers' turns are within rules; stroke judges check the swimmers' strokes; time keepers time the swims; and the referee along with the starter and the officials make sure 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 a "DQ") and the swim is not considered valid.

There are two types of meets. 'A' meets are official meets that allow qualification for a special or bigger meet if the qualifying time is met. Scores are kept to see how each team did at the end of the season. 'B' meets are used as practice meets, where the normal, or prime stroke is swum if not yet qualified. Scores are not kept.

In the USA and the UK, 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.

Masters swimming is a club sport for adults who have a competitive spirit. Swimming at this level differs from competitive club swimming. In swim meets masters are allowed to compete in the 50, 100 and 200 of backstroke, fly and breaststroke and the 50, 100, 200, 500 and 1650 of freestyle. The age groups are organized into 5 year increments (Masters, 1). “Swimming has continually been identified as the best way to exercise. Stress reduction, weight control, cardiovascular fitness, reduced cholesterol, muscle tone and endurance are all positively influenced by exercise. Masters Swimmers swear by it (Masters, 1).” Shoulder injuries are the most common because of the repetitive motion of freestyle, butterfly, and backstroke. Knee injuries often occur from breaststroke due to the unnatural kick. Incorrect stroke technique can also lead to injuries.

[edit] Legendary swimmers

Swimmers who have gained fame for their competition performances include Dawn Fraser, Libby Trickett (formerly Libby Lenton), Kristin Otto, Ian Thorpe, Tamás Darnyi, Krisztina Egerszegi, András Hargitay, Mary Meagher, Michael Phelps, Stephanie Rice, Eamon Sullivan, Susie O'Neill, Janet Evans, Petria Thomas, Alexander Popov, Vladimir Salnikov, Kieran Perkins, Grant Hackett, Pieter van den Hoogenband, Michael Klim, Ian Crocker, Federica Pellegrini, Leisel Jones, Kieran Perkins, Inge de Bruijn, Natalie Coughlin, Lisa Curry-Kenny, Larsen Jensen, Brendan Hansen, Jack Groselle, Mark Spitz, Mark Foster, Simon Burnett, Peter Mankoc, and Aaron Piersol.

[edit] Changes to the sport

Swimming times have dropped over the years due to better training techniques and to new developments.

In the first four Olympics competitions were not held in pools, but in open water (1896- The Mediterranean, 1900- The Seine River, 1904- an artificial lake, 1906- The Mediterranean). The 1904 Olympics' freestyle race was the only one ever measured at 100 yards, instead of the usual 100 meters. A 100 meter pool was built for the 1908 Olympics and sat in the center of the main stadium's track and field oval. The 1912 Olympics, held in the Stockholm harbour, marked the beginning of electronic timing.

Male swimmers wore full body suits until the 1940s, which caused more drag in the water than their modern swim-wear counterparts. Competition suits now include engineered fabric and designs to reduce swimmers' drag in the water and prevent athlete fatigue. Also, over the years, pool designs have lessened the drag. Some design considerations allow for the reduction of swimming resistance, making the pool faster. Namely, proper pool depth, elimination of currents, increased lane width, energy absorbing racing lane lines and gutters, and the use of other innovative hydraulic, acoustic and illumination designs.

The 1924 Olympics were the first to use the standard 50 meter pool with marked lanes. In the freestyle, swimmers originally dove from the pool walls, but diving blocks were incorporated at the 1936 Summer Olympics. The flip-turn was developed by the 1950s. In addition, a split stroke in the breaststroke start and turns have been added to help speed up the stroke.

[edit] Recreational swimming

The most common purpose for swimming is recreation. Recreational swimming is a good way to relax, while enjoying a 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, head up front crawl 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.

A recreational breaststroke swimmer
A recreational breaststroke 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 swimming pools, and calm natural waters (sea, lakes, rivers), therefore front crawl is suitable.

[edit] 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. In the USA, most cities and states have trained lifeguards, such as the Los Angeles City Lifeguards, deployed at pools and beaches. There are a number of specialized swimming styles specially for rescue purposes (see List of swimming styles). Such techniques are studied by lifeguards or members of the Coast Guard. The training for 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 is submerged. Due to regular exposure to large bodies of water, all recruits in the United States Navy, Marine Corps, and Coast Guard are required to complete basic swimming or water survival training.

Swimming is also a professional sport. Companies such as Speedo, TYR Sports, Arena and Nike sponsor swimmers who are at the international level. Cash awards are also given at many of the major competitions for breaking records.[citation needed]

[edit] Swimming as exercise

Swimming is an excellent form of exercise. Because the density of the human body is very similar to that of water, the body is supported by the water and less stress is therefore placed on joints and bones. 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 swimming is believed to reduce the harmful effects of stress. Swimming can improve posture and develop a strong lean physique, often called a "swimmer's build." Muscle development depends upon the stroke and distances trained, but avid swimmers typically have well-developed triceps, upper backs, deltoids, and as well as quadriceps.

[edit] The risks of swimming

A sign warns hikers on the trail to Hanakapiai Beach.
A sign warns hikers on the trail to Hanakapiai Beach.

Swimming is 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:

  • Drowning, inhalation of water arising from
  • Adverse effects of immersion
    • Secondary drowning, where inhaled salt water creates a foam in the lungs that restricts breathing.
    • Salt water aspiration syndrome.
    • Thermal shock after jumping into water can cause the heart to stop.
    • Exostosis which is an abnormal growth in the ear canal due to the frequent, long-term splashing of water into the ear canal. (Known as Swimmer's ear.)
  • Exposure to chemicals
    • Disinfectant Chlorine will increase the pH of the water, if uncorrected the raised pH may cause eye or skin irritations. [1]
    • Chlorine inhalation; breathing small quantities of chlorine gas from the water surface whilst swimming for long periods of time may have an adverse effect on the lungs, particularly for asthmatics. This problem may be resolved by using a pool with better ventilation, with an outdoor pool having the best results.
    • Chlorine also has a negative cosmetic effect after repeated long exposure, stripping brown hair of all color, turning it very light blonde. Chlorine damages the structure of hair, turning it "frizzy." Chlorine can dissolve copper which turns blonde hair green. Proper pool maintenance can reduce the amount of copper in the water, while wetting the hair before entering a pool can help reduce the absorption of copper.
    • Chlorine will often remain on skin in an anhydrous form, even after several washings. The chlorine becomes odorous once it is back in an aqueous solution (when salivated on, during a shower, etc.).
  • Infection
    • Water is an excellent environment for many bacteria, parasites, fungi and viruses affecting humans depending on water quality.
    • Skin infections from both swimming and shower rooms can cause athlete's foot (boat bug). The easiest way to avoid this is to dry the space between the toes. [2]
    • Microscopic parasites such as Cryptosporidium can be resistant to chlorine and can cause diarrheal illness when swimmers swallow pool water.
    • Ear infections, otitis media, (otitis externa).
    • When chlorine levels are improperly balanced, severe health problems may result, such as chronic bronchitis and asthma.
  • Swimmer's own actions
    • Overuse injury; competitive butterfly stroke swimmers for example may develop some back pain, including vertebral fractures in rare cases, and shoulder pain after long years of training, breaststroke swimmers may develop knee pain, and hip pain, and freestyle and backstroke swimmers may develop shoulder pain, commonly referred to as swimmer's shoulder (a form of tendinitis).
    • Hyperventilation in a bid to extend underwater breath-hold times lowers blood carbon dioxide resulting in suppression of the urge to breathe and consequent loss of consciousness towards the end of the dive, see shallow water blackout for the mechanism.
  • Adverse water and weather conditions
    • Currents, including tides and rivers can cause exhaustion, can pull swimmers away from safety, or pull swimmers under water.
    • Wind enhances waves and can blow a swimmer off course.
    • Hypothermia, due to cold water, can cause rapid exhaustion and unconsciousness.
    • Sunburn severity can be increased by reflections in the water and the lack of clothing worn during swimming. Long-term exposure to the sun contributes to risk of skin cancer.
  • Objects in the water
    • Propeller damage is a major cause of accidents, either by being run over by a boat or entanglement on climbing into a boat.
    • Collision with another swimmer, the pool walls, rocks or boats.
    • Diving into a submerged object, or the bottom, often in turbid water.
    • Snagging on underwater objects, particularly submerged branches or wrecks.
    • Stepping on sharp objects such as broken glass.

Organizations publish safety guidelines to help swimmers avoid these risks.[6][7][8]

[edit] Swimming lessons

A styrofoam flotation aid can help children learn to swim.
A styrofoam flotation aid can help children learn to swim.

Children are often given swimming lessons, which serve to develop swimming technique and confidence. Children generally do not swim independently until 4 years of age.[9]

In Sweden, Denmark, Norway and Finland, the curriculum for the fifth grade states that all children should learn how to swim as well as how to handle emergencies near water. Most commonly, children are expected to be able to swim 200 metres (220 yards) – of which at least 50 metres (55 yards) on their back – after first falling into deep water and getting their head under water. Even though about 95 percent of Swedish school children know how to swim, drowning remains the third most common cause of death among children.[10]

In both the Netherlands and Belgium swimming lessons under school time (schoolzwemmen, school swimming) are supported by the government. Most schools provide swimming lessons. There is a long tradition of swimming lessons in the Netherlands and Belgium, the Dutch translation for the breaststroke swimming style is even schoolslag (schoolstroke). The children learn a variant of the breaststroke which is technically not entirely correct.

In many places, swimming lessons are provided by local swimming pools, both those run by the local authority and by private leisure companies. Many schools also include swimming lessons into their Physical Education curricula, provided either in the schools' own pool, or in the nearest public pool.

In the UK, the "Top-ups scheme" calls for school children who cannot swim by the age of 11 to receive intensive daily lessons. These children who have not reached Great Britain's National Curriculum standard of swimming 25 metres by the time they leave primary school will be given a half-hour lesson every day for two weeks during term-time.[11]

In Canada and Mexico there has been a call for swimming to be included in the public school curriculum.[12]

[edit] Swimsuits

Main article: swimsuit

Most standard clothing is impractical and unsafe for swimming. In historical cultures, it has been common to swim nude, but in those with taboos against nudity, specialized swimwear has been the norm. Most cultures today expect swimsuits to be worn for public swimming.

Modern men's swimsuits are usually shorts also known as jammers, either skintight or loose fitting, covering only the upper legs or not at all. Almost always, the upper body is left uncovered. In some cultures, custom and/or laws have required tops for public swimming.

Modern women's swimsuits are generally skintight, either two pieces covering only the breasts and pelvic region, or a single piece covering them both plus the torso between them. Skirts are uncommon and short when included, but have been required and sometimes as much as full length in some cultures.

Competitive swimwear seeks to improve upon bare human skin for a speed advantage. For extra speed a swimmer wears a body suit, which has rubber or plastic bumps that break up the water close to the body and provides a small amount of thrust--just barely enough to help a swimmer swim faster. For swimming in cold water, wetsuits provide thermal insulation.

Swim caps keep the body streamlined.

[edit] See also

[edit] References

[edit] Bibliography

  • Bender N. & Hirt N., Did Turkish Van cats lose theyr fear of water? Forschungspraktikum Evolutionsökologie, University of Bern, Bern 2002.
  • Bender R., Die evolutionsbiologische Grundlage des menschlichen Schwimmens, Tauchens und Watens: Konvergenzforschung in den Terrestrisierungshypothesen und in der Aquatic Ape Theory. Diploma thesis, Institute of Sport and Sport Sciences, University of Bern, Bern 1999.
  • Cox, Lynne (2005 by Harvest Books). Swimming to Antarctica: Tales of a Long-Distance Swimmer. 2005 by Harvest Books. ISBN 0-15-603130-2. 
  • Maniscalco F., Il nuoto nel mondo greco romano, Naples 1993.
  • Mehl H., Antike Schwimmkunst, Munchen 1927.
  • Schuster G., Smits W. & Ullal J., Thinkers of the Jungle. Tandem Verlag 2008.
  • Sprawson, Charles (2000). Haunts of the Black Masseur - The Swimmer as Hero. University of Minnesota Press. ISBN 0-8166-3539-0. svin
  • Tarpinian, Steve (1996). The Essential Swimmer. The Lyons Press. ISBN 1-55821-386-4. 
  • Widmer F., Ein erster Vergleich des Verhaltens am Wasser zwischen Hauskatzen und Türkischen Van-Katzen. Diploma thesis, University of Zurich, Zurich 1990.

[edit] External links

Wikimedia Commons has media related to:
Look up Swimming in
Wiktionary, the free dictionary.


aa - ab - af - ak - als - am - an - ang - ar - arc - as - ast - av - ay - az - ba - bar - bat_smg - bcl - be - be_x_old - bg - bh - bi - bm - bn - bo - bpy - br - bs - bug - bxr - ca - cbk_zam - cdo - ce - ceb - ch - cho - chr - chy - co - cr - crh - cs - csb - cu - cv - cy - da - de - diq - dsb - dv - dz - ee - el - eml - en - eo - es - et - eu - ext - fa - ff - fi - fiu_vro - fj - fo - fr - frp - fur - fy - ga - gan - gd - gl - glk - gn - got - gu - gv - ha - hak - haw - he - hi - hif - ho - hr - hsb - ht - hu - hy - hz - ia - id - ie - ig - ii - ik - ilo - io - is - it - iu - ja - jbo - jv - ka - kaa - kab - kg - ki - kj - kk - kl - km - kn - ko - kr - ks - ksh - ku - kv - kw - ky - la - lad - lb - lbe - lg - li - lij - lmo - ln - lo - lt - lv - map_bms - mdf - mg - mh - mi - mk - ml - mn - mo - mr - mt - mus - my - myv - mzn - na - nah - nap - nds - nds_nl - ne - new - ng - nl - nn - no - nov - nrm - nv - ny - oc - om - or - os - pa - pag - pam - pap - pdc - pi - pih - pl - pms - ps - pt - qu - quality - rm - rmy - rn - ro - roa_rup - roa_tara - ru - rw - sa - sah - sc - scn - sco - sd - se - sg - sh - si - simple - sk - sl - sm - sn - so - sr - srn - ss - st - stq - su - sv - sw - szl - ta - te - tet - tg - th - ti - tk - tl - tlh - tn - to - tpi - tr - ts - tt - tum - tw - ty - udm - ug - uk - ur - uz - ve - vec - vi - vls - vo - wa - war - wo - wuu - xal - xh - yi - yo - za - zea - zh - zh_classical - zh_min_nan - zh_yue - zu -