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. Almost all mammals can swim by instinct, including bats, kangaroos, moles and sloths. The few exceptions include apes and possibly giraffes and porcupines. 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 suited to water.
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. 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 to 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 In an unpublished research carried out 2002 at the University of Bern (Switzerland) , Bender & Hirt showed that the Turkish Van has less inhibition to enter in shallow water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 Dromedary and Bactrian camels, can swim, 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.
The Guinea pig (or cavy) is noted as having an excellent swimming ability.. 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. 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.
The goal of competitive swimming is to be the fastest over a given distance. Competitive swimming became popular in the nineteenth century, and comprises 36 individual events - 18 male events and 18 female events, however the IOC only recognizes 34 events - 17 male 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 front crawl (freestyle). "Freestyle" and "front crawl" are often used interchangeably, but "freestyle" properly refers to an unregulated competitive event rather than to any particular stroke. Swimmers generally choose to swim front crawl in a freestyle event since it is the fastest stroke. In events that require specific strokes, 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 has a different stroke order. In the medley, the 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 officials:
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.
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.
Swimming times have dropped over the years due to better training techniques and to new developments.
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 Summer 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 and goggles first were used in the 1976 Olympics.
There were also changes in the late 20th century in terms of technique. Breaststrokers are now allowed to dip their head completely under water, which allowed for a longer stroke and faster time. In addition, a split stroke in the breaststroke start and turns have been added to help speed up the stroke. Backstrokers are now allowed to turn on their stomachs before the wall in order to perform a "flip-turn". Previously, they had to reach and flip backwards.
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.
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.
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."
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:
Organizations publish safety guidelines to help swimmers avoid these risks.
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.
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.
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.
Modern men's swimsuits are usually shorts, either skintight (jammers) or loose fitting (swim trunks), 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.