Swimming techniques and general swimming information ...
What is swimming ...
Composed primarily of water as we are, at 70 % we as a species are
near to the density of water.
But since only roughly 70% of our bodies is water, we are slightly
less dense than water, which when entered exerts a buoyant force
upon the body. Which makes us stay afloat and requires only a slight
thrust of water downward relative to body mass, A small thrust of
water in a direction opposite to the direction of intended motion,
causes us to move through the water with relative ease.
This thrust is typically accomplished by the hands and using them
as paddles, and by kicking the legs to push water away from the
body.
Now you know what swimming is .... the article below explains
how to improve your technique ...
Dynamics of swimming explained ... People enjoy swimming/bathing, especially on a hot day. However,
the level of swimming skill varies greatly between recreational
and competitive. Even at competitive level, some swimmers are faster
than others. The difference lies in the ability to use the fundamental
principles of fluid dynamics to gain an advantage. The principal
which makes the best swimmers fast are employed by anyone who has
ever treaded water.
In order to understand how the principals work, we
must understand the forces acting on swimmers. There are four forces
that act on a swimmer. These are similar to the forces acting on
a jet or airplane and are presented in the image below.
In the vertical plane, the weight of the swimmer is offset by the
buoyancy. However, since people have varying natural ability to
float, another means of overcoming the swimmers weight must be applied.
Accomplished from the arm stroke and kick. By pushing down on the
water, Equal an opposite reactions occur which lifts the swimmer
up high in the water rather than sinking.
Drag can be divided into two components:
Pressure drag and friction drag.
The pressure drag comes from the frontal body area exposed to the
water and the separation level that occurs behind the swimmer. This
is similar to the pressure drag of the smooth ball. In order to
reduce the drag of golf ball, dimples were introduced which changed
the nature of the flow from laminar to turbulent. The turbulent
flow delays separation and therefore reduces the pressure drag.
However, the flow around a swimmer is already turbulent. Therefore,
a swimmer must streamline his body to reduce the amount of separation
as shown in the image.
The drag from the friction, on the other hand, increases when the
swimmer becomes more streamline since more surface area is exposed
to the water. This is not really a problem, as the pressure drag
is dominant and, therefore, the overall drag decreases.
Arm Stroke
Generally speaking, the arm stroke produces the majority of the
thrust. The difference between swimmers is how the arm stroke is
used to produce thrust. Good swimmers not only achieve thrust pushing
back on the water, but also by moving their hands and arms like
a wheel in a large circular motion.
The most obvious production of thrust does come from pushing back
on the water like a paddle or rowing a boat.
Straight arm pulls are the most efficient and powerful.
As shown in the animation below ...
Kick Stroke
The kick provides a stabilizing effect in addition to the propulsive
force. Most swimmers only get a minimal amount of propulsive force
from their kick. The way to improve the kick is to keep your feet
in the water. When a swimmers feet enter the water, a significant
amount of oxygen enters. This air increases drag as well as reducing
the propulsive effect and efficiency of kicking. Good swimmers go
further by moving their feet during the kick to produce the same
lift force made by their hands.
A good kicking motion helps you stay streamline as shown below,
the more streamline you are in the water the less drag you produce
therefore less thrust is lost allowing the swimmer to move smoothly
through the water.
Round up.
Working on these small points individually can vastly increase the
overall performance and speed of your length time, try to concentrate
on one at a time till you understand the technique and can apply
it to your stroke like second nature then work on another area,
some bad habits are hard to break.
The history of swimming ...
Think it's a new sport? ha ha ha ...
2500 BC - First Egyptian hieroglyphics depicting swimming
400 BC - Egyptians and Romans leisurely dived off cliffs
36 BC - Japanese Emperor Suigiu encouraged swimming
78 AD - Romans introduced swimming to Britain as a manly social
event
7th Century - Plagues unnerved swimming during the Dark Ages
14th Century - Medieval knights to master swimming in armour
15th Century - Church objected to naked bathing on moral grounds.
16th Century - Oxford and Cambridge University banned swimming after
fatalities.
16th Century - Swim author Digby claimed humans are better swimmers
than fish.
17th Century - Japanese Emperor Go-Yoozei ruled that schoolchildren
should swim.
17th
Century - Medicinal value of
natural spa springs discovered in Britain.
18th Century - Sea swimming popularized by George III
19th Century - Germany and Sweden developed acrobatic diving.
1844 - Red Indians 'crawl' style 'discovered' by the British.
1845 - First swimming championship debut in Sydney.
1875 - Captain Webb pioneered the English Channel crossing.
1885 - First diving competition, Germany.
1892 - First women's championship, Scotland.
1908 - The Federation Internationale de Natation de Amateur (FINA)
formed.
1924 - Johnny Weissmuller set 67 world records, then became 'Tarzan'.
1824 - Canadian sportswomen premiered sychronised swimming.
1950 - Butterfly born as a Breaststroke spin off.
1986 - Sychronised swimming a Commonwealth Games event.
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