
Swimming is the self-
propulsion
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...
of a person through
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that results in directional motion. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response.
Swimming is consistently among the top public recreational activities, and in some countries,
swimming lessons
Swimming lessons are the process of learning to swim. In most countries there is a definition of a number of swimming levels that are reached in the process of the curriculum. The respective certificates of swimming tests are required for furth ...
are a compulsory part of the educational curriculum. As a formalized sport, swimming is featured in a range of local, national, and international competitions, including every modern
Summer Olympics
The Summer Olympic Games (french: link=no, Jeux olympiques d'été), also known as the Games of the Olympiad, and often referred to as the Summer Olympics, is a major international multi-sport event normally held once every four years. The ina ...
.
Swimming involves repeated motions known as
strokes
Stroke (also known as a cerebrovascular accident (CVA) or brain attack) is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, ...
in order to propel the body forward. While the
front crawl
The front crawl or forward crawl, also known as the Australian crawl or American crawl, is a swimming stroke usually regarded as the fastest of the four front primary strokes. As such, the front crawl stroke is almost universally used during a ...
, also known as
freestyle
Freestyle may refer to:
Brands
* Reebok Freestyle, a women's athletic shoe
* Ford Freestyle, an SUV automobile
* Coca-Cola Freestyle, a vending machine
* ICD Freestyle, a paintball marker
* Abbott FreeStyle, a blood glucose monitor by Abbott La ...
, is widely regarded as the fastest out of four primary strokes, other strokes are practiced for special purposes, such as for training.
There are various risks present during swimming, mainly due to it taking place in water. Swimmers are at risk of incapacitation due to
panic
Panic is a sudden sensation of fear, which is so strong as to dominate or prevent reason and logical thinking, replacing it with overwhelming feelings of anxiety and frantic agitation consistent with an animalistic fight-or-flight reac ...
and
exhaustion
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
, which may cause death due to
drowning
Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer a ...
. Other dangers include getting an
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...
or contact with hostile aquatic fauna. To minimize these risks, most facilities employ a
lifeguard
A lifeguard is a rescuer who supervises the safety and rescue of swimmers, surfers, and other water sports participants such as in a swimming pool, water park, beach, spa, river and lake. Lifeguards are trained in swimming and Cardiopulmonary ...
to look for signs of distress.
Swimmers often wear specialized
swimwear
A swimsuit is an item of clothing designed to be worn by people engaging in a water-based activity or water sports, such as swimming, diving and surfing, or sun-orientated activities, such as sun bathing. Different types may be worn by men, w ...
, although depending on the culture of the area, some swimmers may also swim
nude
Nudity is the state of being in which a human is without clothing.
The loss of body hair was one of the physical characteristics that marked the biological evolution of modern humans from their hominin ancestors. Adaptations related to h ...
or wear their day attire. In addition to this, a variety of equipment can be used to enhance the swimming experience or performance, including but not limited to the use of
swimming goggles
Goggles, or safety glasses, are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and ...
,
floatation device
A personal flotation device (PFD; also referred to as a life jacket, life preserver, life belt, Mae West, life vest, life saver, cork jacket, buoyancy aid or flotation suit) is a flotation device in the form of a vest or suite that is worn by a ...
s,
swim fins
Swimfins, swim fins, diving fins, or flippers are finlike accessories worn on the feet, legs or hands and made from rubber, plastic, carbon fiber or combinations of these materials, to aid movement through the water in water sports activities su ...
, and
snorkels.
Science
Swimming relies on the nearly
neutral buoyancy
Neutral buoyancy occurs when an object's average density is equal to the density of the fluid in which it is immersed, resulting in the buoyant force balancing the force of gravity that would otherwise cause the object to sink (if the body's densi ...
of the human body. On average, the body has a
relative density
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...
of 0.98 compared to water, which causes the body to float. However, buoyancy varies on the basis of body composition, lung inflation, muscle and fat content, centre of gravity and the salinity of the water. Higher levels of body fat and saltier water both lower the relative density of the body and increase its buoyancy. Human males tend to have a lower centre of gravity and higher muscle content, therefore find it more difficult to float or be buoyant. See also: ''
Hydrostatic weighing
Hydrostatic weighing, also referred to as underwater weighing, hydrostatic body composition analysis and hydrodensitometry, is a technique for measuring the density of a living person's body. It is a direct application of Archimedes' principle, ...
.''
Since the human body is less dense than water, water is able to support the weight of the body during swimming. As a result, swimming is “low-impact” compared to land activities such as running. The density and
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
of water also create resistance for objects moving through the water.
Swimming strokes use this resistance to create propulsion, but this same resistance also generates drag on the body.
Hydrodynamics is important to stroke technique for swimming faster, and swimmers who want to swim faster or exhaust less try to reduce the drag of the body's motion through the water. To be more hydrodynamically effective, swimmers can either increase the power of their strokes or reduce water resistance, though power must increase by a factor of three to achieve the same effect as reducing resistance.
Efficient swimming by reducing water resistance involves a horizontal water position, rolling the body to reduce the breadth of the body in the water, and extending the arms as far as possible to reduce wave resistance.
[
Just before plunging into the pool, swimmers may perform exercises such as ]squatting
Squatting is the action of occupying an abandoned or unoccupied area of land or a building, usually residential, that the squatter does not own, rent or otherwise have lawful permission to use. The United Nations estimated in 2003 that there ...
. Squatting helps in enhancing a swimmer's start by warming up the thigh muscles.
Infant swimming
Human babies demonstrate an innate swimming or diving reflex
The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It op ...
from newborn until the age of approximately 6 months. Other mammals also demonstrate this phenomenon (see mammalian diving reflex
The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It op ...
). The diving response involves apnea
Apnea, BrE: apnoea, is the temporal cessation of breathing. During apnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. Depending on how blocked the airways are (patency), there may ...
, reflex bradycardia
Reflex bradycardia is a bradycardia (decrease in heart rate) in response to the baroreceptor reflex, one of the body's homeostatic mechanisms for preventing abnormal increases in blood pressure. In the presence of high mean arterial pressure, ...
, and peripheral vasoconstriction
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood ve ...
; in other words, babies immersed in water spontaneously hold their breath, slow their heart rate, and reduce blood circulation to the extremities (fingers and toes).
Because infants are innately able to swim, classes for babies of about 6 months old are offered in many locations. This helps build muscle memory and makes strong swimmers from a young age.
Technique
Swimming can be undertaken using a wide range of styles, known as 'strokes,' and these strokes are used for different purposes, or to distinguish between classes in competitive swimming. It is not necessary to use a defined stroke for propulsion through the water, and untrained swimmers may use a 'doggy paddle
The dog paddle or doggy paddle is a simple swimming style. It is characterized by the swimmer lying on their chest and moving their hands and legs alternately in a manner reminiscent of how dogs and other quadrupedal mammals swim. It is effective ...
' of arm and leg movements, similar to the way four-legged animals swim.
There are four main strokes used in competition and recreation swimming: the front crawl
The front crawl or forward crawl, also known as the Australian crawl or American crawl, is a swimming stroke usually regarded as the fastest of the four front primary strokes. As such, the front crawl stroke is almost universally used during a ...
, also known as freestyle, breaststroke
Breaststroke is a swimming style in which the swimmer is on their chest and the torso does not rotate. It is the most popular recreational style due to the swimmer's head being out of the water a large portion of the time, and that it can b ...
, backstroke
Backstroke or back crawl is one of the four swimming styles used in competitive events regulated by FINA, and the only one of these styles swum on the back. This swimming style has the advantage of easy breathing, but the disadvantage of swimme ...
and butterfly
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...
. Competitive swimming in Europe started around 1800, mostly using the breaststroke. In 1873, John Arthur Trudgen introduced the trudgen
The trudgen is a swimming stroke sometimes known as the ''racing stroke'', or the ''East Indian stroke''. It is named after the English swimmer John Trudgen (1852–1902) and evolved out of sidestroke.
One swims mostly upon one side, making an ov ...
to Western swimming competitions. Butterfly was developed in the 1930s, and was considered a variant of the breaststroke until accepted as a separate style in 1953. Butterfly is considered the hardest stroke by many people, but it is the most effective for all-around toning and the building of muscles. It also burns the most calories and can be the second fastest stroke if practiced regularly.
In non-competitive swimming, there are some swimming strokes including sidestroke
The sidestroke is a swimming stroke, so named because the swimmer lies on one's side with asymmetric arm and leg motion. It is helpful as a lifesaving technique and is often used for long-distance swimming. The sidestroke allows the swimmer increa ...
. The sidestroke toward the end of the 19th century, this pattern was changed by raising one arm above the water first, then the other, and then each in turn. It is still used in lifesaving and recreational swimming.
Other strokes exist for particular reasons such as training, school lessons, and rescue, and it is often possible to change strokes to avoid using parts of the body, either to separate specific body parts, such as swimming with only arms or legs to exercise them harder, or for amputees or those affected by paralysis.
History
Swimming has been recorded since prehistoric times, and the earliest records of swimming date back to Stone Age paintings
Painting is the practice of applying paint, pigment, color or other medium to a solid surface (called the "matrix" or "support"). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and ai ...
from around 7,000 years ago. Written references date from 2000 BC. Some of the earliest references include the Epic of Gilgamesh
The ''Epic of Gilgamesh'' () is an epic poem from ancient Mesopotamia, and is regarded as the earliest surviving notable literature and the second oldest religious text, after the Pyramid Texts. The literary history of Gilgamesh begins wit ...
, the Iliad
The ''Iliad'' (; grc, Ἰλιάς, Iliás, ; "a poem about Ilium") is one of two major ancient Greek epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by modern audiences. As with the '' Odys ...
, the Odyssey
The ''Odyssey'' (; grc, Ὀδύσσεια, Odýsseia, ) is one of two major Ancient Greek literature, ancient Greek Epic poetry, epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by moder ...
, the Bible
The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts o ...
(Ezekiel 47:5, Acts 27:42, Isaiah 25:11), Beowulf
''Beowulf'' (; ang, Bēowulf ) is an Old English Epic poetry, epic poem in the tradition of Germanic heroic legend consisting of 3,182 Alliterative verse, alliterative lines. It is one of the most important and List of translations of Beo ...
, and other sagas.
The coastal tribes living in the volatile Low Countries
The term Low Countries, also known as the Low Lands ( nl, de Lage Landen, french: les Pays-Bas, lb, déi Niddereg Lännereien) and historically called the Netherlands ( nl, de Nederlanden), Flanders, or Belgica, is a coastal lowland region in N ...
were known as excellent swimmers by the Romans
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
. Men and horses of the Batavi tribe could cross the Rhine
The Rhine ; french: Rhin ; nl, Rijn ; wa, Rén ; li, Rien; rm, label=Sursilvan, Rein, rm, label=Sutsilvan and Surmiran, Ragn, rm, label=Rumantsch Grischun, Vallader and Puter, Rain; it, Reno ; gsw, Rhi(n), including in Alsatian dialect, Al ...
without losing formation, according to Tacitus
Publius Cornelius Tacitus, known simply as Tacitus ( , ; – ), was a Roman historian and politician. Tacitus is widely regarded as one of the greatest Roman historians by modern scholars.
The surviving portions of his two major works—the ...
. Dio Cassius describes one surprise tactic employed by Aulus Plautius
Aulus Plautius was a Roman politician and general of the mid-1st century. He began the Roman conquest of Britain in 43, and became the first governor of the new province, serving from 43 to 46 CE.
Career
Little is known of Aulus Plautius's e ...
against the Celts
The Celts (, see pronunciation for different usages) or Celtic peoples () are. "CELTS location: Greater Europe time period: Second millennium B.C.E. to present ancestry: Celtic a collection of Indo-European peoples. "The Celts, an ancien ...
at the Battle of the Medway
The Battle of the Medway took place in 43 AD, probably on the River Medway in the lands of the Iron Age tribe of the Cantiaci, now the English county of Kent. Other locations for the battle have been suggested but are less likely. This was an ...
:
The ritish Celtsthought that Romans would not be able to cross it without a bridge, and consequently bivouacked in rather careless fashion on the opposite bank; but he sent across a detachment of atavii who were accustomed to swim easily in full armour across the most turbulent streams. . . . Thence the Britons retired to the river Thames at a point near where it empties into the ocean and at flood-tide forms a lake. This they easily crossed because they knew where the firm ground and the easy passages in this region were to be found, but the Romans in attempting to follow them were not so successful. However, the ataviiswam across again and some others got over by a bridge a little way up-stream, after which they assailed the barbarians from several sides at once and cut down many of them."
In 1538, Nikolaus Wynmann, a Swiss–German professor of languages, wrote the earliest known complete book about swimming, ''Colymbetes, sive de arte natandi dialogus et festivus et iucundus lectu'' (''The Swimmer, or A Dialogue on the Art of Swimming and Joyful and Pleasant to Read'').
Purpose
There are many reasons why people swim, from swimming as a recreational pursuit to swimming as a necessary part of a job or other activity. Swimming may also be used to rehabilitate injuries, especially various cardiovascular and muscle injuries. People may also pursue swimming as a career or field of interest. Some may be gifted and choose to compete professionally and go onto claim fame.
Recreation
Many swimmers swim for recreation, with swimming consistently ranking as one of the physical activities people are most likely to take part in. Recreational swimming can also be used for exercise, relaxation or rehabilitation. The support of the water, and the reduction in impact, makes swimming accessible for people who are unable to undertake activities such as running. Swimming is one of the most relaxing activities, water is known to calm us and can help reduce stress.
Health
Swimming is primarily a cardiovascular/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. Furthermore, swimming can help tone and strengthen muscles. Swimming allows sufferers of arthritis
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In some ...
to exercise affected joints without worsening their symptoms. However, swimmers with arthritis may wish to avoid swimming breaststroke, as improper technique can exacerbate arthritic knee pain. As with most aerobic exercise, swimming reduces the harmful effects of stress. Swimming is also effective in improving health for people with cardiovascular problems and chronic illnesses. It is proven to positively impact the mental health of pregnant women and mothers. Swimming can even improve mood. Although many forms of physical activity have been shown to improve bone density
Bone density, or bone mineral density, is the amount of bone mineral in bone tissue. The concept is of mass of mineral per volume of bone (relating to density in the physics sense), although clinically it is measured by proxy according to op ...
and health, this is where swimming has its downfalls. Due to the low-impact nature of the sport, studies have demonstrated that bone mass acquisition will be negatively impacted, which could be an issue for adolescent athletes in particular. Regular swimming activities contribute to the restoration of health, and in many cases, complete recovery. Activity in water is the basis for a good work of the heart muscle, the endocrine system of the body, stable blood pressure, full blood circulation in the vessels, which is not only the prevention of a lot of problems but also a powerful healing effect without any side effects.
Disabled swimmers
Since 2010, the Americans with Disabilities Act
The Americans with Disabilities Act of 1990 or ADA () is a civil rights law that prohibits discrimination based on disability. It affords similar protections against discrimination to Americans with disabilities as the Civil Rights Act of 19 ...
has required that swimming pool
A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming or other leisure activities. Pools can be built into the ground (in-ground pools) or built ...
s in the United States be accessible to disabled swimmers.
Elderly swimmers
"Water-based exercise can benefit older adults by improving quality of life and decreasing disability. It also improves or maintains the bone health of post-menopausal women."
Swimming is an ideal workout for the elderly, as it is a low-impact sport with very little risk of injury. Exercise in the water works out all muscle groups, helping with conditions such as muscular dystrophy which is common in seniors. It is also a common way to relieve pain from arthritis.
Sport
Swimming as a sport predominantly involves participants competing to be the fastest over a given distance in a certain period of time. Competitors swim different distances in different levels of competition. For example, swimming has been an Olympic sport
Olympic sports are contested in the Summer Olympic Games and Winter Olympic Games. The 2020 Summer Olympics included 33 sports; the 2022 Winter Olympics included seven sports. Each Olympic sport is represented by an international governing b ...
since 1896, and the current program includes events from 50 m to 1500 m in length, across all four main strokes and medley. During the season competitive swimmers typically train several times a week, this is in order to preserve fitness as well as promoting overload in training. Furthermore when the cycle of work is completed swimmers go through a stage called taper where intensity is reduced in preparation for racing, during taper power and feel in the water are concentrated.
The sport is governed internationally by the Fédération Internationale de Natation (FINA), and competition pools for FINA events are 25 or 50 meters in length. In the United States, a pool 25 yards in length is commonly used for competition.
Other swimming and water-related sporting disciplines include open water swimming
Open water swimming is a swimming discipline which takes place in outdoor bodies of water such as open oceans, lakes, and rivers.
The beginning of the modern age of open water swimming is sometimes taken to be May 3, 1810, when Lord Byron swam ...
, diving
Diving most often refers to:
* Diving (sport), the sport of jumping into deep water
* Underwater diving, human activity underwater for recreational or occupational purposes
Diving or Dive may also refer to:
Sports
* Dive (American football), ...
, synchronized swimming
Synchronized swimming (in British English, synchronised swimming) or artistic swimming is a sport where swimmers perform a synchronized choreographed routine, accompanied by music. The sport is governed internationally by FINA (the ''Fédérati ...
, water polo
Water polo is a competitive team sport played in water between two teams of seven players each. The game consists of four quarters in which the teams attempt to score goals by throwing the ball into the opposing team's goal. The team with t ...
, triathlon
A triathlon is an endurance multisport race consisting of swimming, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each segment sequentially with the time transitioning between the d ...
, and the modern pentathlon
The modern pentathlon is an Summer Olympics, Olympic sport consisting of fencing (sport), fencing (one-touch épée), freestyle swimming, show jumping, equestrian show jumping, pistol shooting, and cross country running. The event is inspired by t ...
.
Safety
As a popular leisure activity done all over the world, one of the primary risks of swimming is drowning
Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer a ...
. Drowning may occur from a variety of factors, from swimming fatigue to simply inexperience in the water. From 2005 to 2014, an average of 3,536 fatal unintentional drownings occurred in the United States, approximating 10 deaths a day.
To minimize the risk and prevent potential drownings from occurring, lifeguards
A lifeguard is a rescuer who supervises the safety and rescue of swimmers, surfers, and other water sports participants such as in a swimming pool, water park, beach, spa, river and lake. Lifeguards are trained in swimming and CPR/ AED first a ...
are often employed to supervise swimming locations such as pools, waterparks, lakes and beaches. Different lifeguards receive different training depending on the sites that they are employed at; i.e. a waterfront lifeguard receives more rigorous training than a poolside lifeguard. Well-known aquatic training services include th
National Lifesaving Society
and the Canadian Red Cross
The Canadian Red Cross Society ()[abalone
Abalone ( or ; via Spanish , from Rumsen ''aulón'') is a common name for any of a group of small to very large marine gastropod molluscs in the family Haliotidae. Other common names are ear shells, sea ears, and, rarely, muttonfish or mu ...]
and pearl
A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium ca ...
diving, and spearfishing
Spearfishing is a method of fishing that involves impaling the fish with a straight pointed object such as a spear, gig or harpoon. It has been deployed in artisanal fishing throughout the world for millennia. Early civilisations were famil ...
.
Swimming is used to rescue people in the water who are in distress, including exhausted swimmers, non-swimmers who have accidentally entered the water, and others who have come to harm on the water. Lifeguard
A lifeguard is a rescuer who supervises the safety and rescue of swimmers, surfers, and other water sports participants such as in a swimming pool, water park, beach, spa, river and lake. Lifeguards are trained in swimming and Cardiopulmonary ...
s or volunteer lifesavers are deployed at many pools and beaches worldwide to fulfil this purpose, and they, as well as rescue swimmer
Rescue swimmer is a designation given to rescue specialists, most commonly in the service of the military. Rescue swimmers usually are charged with the rescue, assessment, and rendering of medical aid to persons in distress in the sea, on the land ...
s, may use specific swimming styles
Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...
for rescue purposes.
Swimming is also used in marine biology
Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifie ...
to observe plants and animals in their natural habitat. Other sciences use swimming; for example, Konrad Lorenz
Konrad Zacharias Lorenz (; 7 November 1903 – 27 February 1989) was an Austrian zoologist, ethologist, and ornithologist. He shared the 1973 Nobel Prize in Physiology or Medicine with Nikolaas Tinbergen and Karl von Frisch. He is often rega ...
swam with geese as part of his studies of