Swimming is simple; it consists of two parts -- pulling and kicking. However, swimming is not all about strength, technique, or skill; it is also about fluid dynamics, drag reduction, and body structure. Due to drag reduction, some swimmers will go to extremes to reduce drag. How efficiently a swimmer kicks and pulls is also influenced by the viscosity of the water (the thickness of the water). As well as having strong muscles throughout the body because almost every muscle is used while swimming, there are many variables that effect the speed of a swimmer.
Several forces slow down a swimmer; two examples being friction and drag.Water is 700 times denser than air, 55 times more viscous (Gibo, 2005, para. 3), and 1,000 times more resistant (Koff, Matkovich, McPhilips, 2004, para. 1). Because of this density, viscosity, resistance, drag heavily affects a swimmer’s speed. A liquid’s viscosity increases as its temperature decreases (“Viscosity”, n.d., para. 1). The average water temperature for an athletic pool is 25.5-27.5 degrees Celsius, giving pool water a relatively high viscosity (“Air and Water Temperature Guidelines”, n.d., para. 21). Friction is caused by the constant contact between the swimmer and the water molecules (Gibo, 2005, para. 4), causing what is known as friction drag. Friction drag comes into play the most when the swimmer is at racing speeds. "The pressure around the swimmer increases due to the difference in water velocities directly around his or her body” (Gibo, 2005, para. 6). Because drag has such a large impact, swimmers will try to reduce their drag as much as possible.
Two ways swimmers can reduce the amount of drag they create is by means of shaving and using the right equipment, such as hydro dynamic goggles and slick swimsuits. Shaving before a race “significantly [reduces] the rate of velocity decay. It is concluded that removing body hair reduces active drag” (Sharp, Costill, 1998, para. 1). Shaving removes body hair and dead skin cells, thereby reducing drag. Swim suits are another viable option, some being even “smoother than hairy or shaven skin” (Nasr, n.d., para. 4). The reason the high-tech suits cut so much drag is because they are welded. Jason Rance, former head of Speedo's research and design unit, says that “Welding cut viscous drag by 6 percent as compared to sewing…”. The suits also have what is known as a ‘core stabilizer’. This helps the swimmer engage their core, thus making them faster. The suit is coated with a water-repellent, making the suit lighter and more buoyant (Nasr, para. 2).
The body’s movements are controlled by the muscular system; groups of tissue located under the skin that contract and relax to move the body (Nagel, 2002, p. 1309 para. 5). While swimming, a person uses all the major muscle groups in his or her body, which is very beneficial considering that makes up almost half of the body’s weight (Jakab, 2006, p. 6 para. 3). The most stress...