Swimming plan: Swimming is the self Science Recreation Swimming

Infant swimming

Main article: Infant swimming
Human babies demonstrate an innate swimming or diving reflex from newborn until the age of approximately 6 months.^[9] Other mammals also demonstrate this phenomenon (see mammalian diving reflex). The diving response involves apnea, reflex bradycardia, and peripheral vasoconstriction; 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).^[9] 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[edit]

See also: Swimming stroke
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' 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, also known as freestyle, breaststroke, backstroke and butterfly. Competitive swimming in Europe started around 1800, mostly using the breaststroke. In 1873, John Arthur Trudgen introduced the trudgen to Western swimming competitions.^[10] Butterfly was developed in the 1930s, and was considered a variant of the breaststroke until accepted as a separate style in 1953.^[11] Butterfly is considered the hardest stroke by many people, but it is the most effective for all-around toning and the building of muscles.^[12] It also burns the most calories and can be the second fastest stroke if practiced regularly.^[12]
In non-competitive swimming, there are some swimming strokes including sidestroke. 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.