Deni Avramidou –
mob +357 99 639565
Xara Loizou –
mob. +357 99 323032Christos Chrysafis –
mob. +357 99 269999
Margarita Andreou –
Water Polo the Sport of Stamina…
The basic principle of swimming is buoyancy. The human body has a high water content and its density is close to the density of water. Due to its cavities (most prominently the lungs), the average density of the human body is lower than that of water, so it naturally floats. Terry Laughlin has summarized the relevant physical principles for effective and efficient swimming in his book “Total Immersion” in 1996. There are two ways to swim faster:
- Increase power
- Reduce water resistance
Because the power needed to overcome resistance increases with the third power of the velocity the first option is not really effective. To increase velocity by 10% you’d need to increase the power by more than 30%. Laughlin gives three physical principles to reduce drag in swimming:
Balance: how to have a horizontal water position
Due to the lungs the center of buoyancy and the center of gravity of the human body are not the same. Therefore the lower body has a tendency to sink. If the body is not horizontal but even slightly inclined the area it offers to drag is much higher leading to higher resistance. An easy way to stay horizontal is to lean forward and position your head straight in the extension of the spine. In this position the eyes are directed straight downward and the head is more immersed (therefore total immersion). At the water surface, resistance is proportional to the breadth of a boat. Laying flat on the chest in freestyle or on the back in backstroke exposes the breadth of the body to the water. Rolling on the side reduces the breadth and the resistance. In freestyle and backstroke you should roll from one side to the other in the stroke and glide on the side as much as possible. When taking a breath you should take them as little as possible, for beginners it is good to breath every three strokes and the more trained you are the more strokes in between each breath.
Sailboats are categorized according to boat length. This is due to the wave resistance at the surface. According to Froude, a naval architect in the 19th century, a body moving at the surface of the water creates a wave. The length of the wave depends on the speed. The faster the boat the longer the wave. Now Froude found that resistance goes up dramatically when the wave length reaches the length of the boat. There is a simple formula connecting wave velocity to wave length (dispersion equation, metric):
Here c is the velocity of the wave in m/s, g is the gravitational acceleration (9.81 m/s2), and l is the wave length in m. If the maximum swimming speed of c=2.1 m/s is entered you get a length of l=2.82 m. This is about the length of a 2 m swimmer with extended arms. So the longer you can glide with the extended arm the less wave resistance. This is also called front quadrant swimming.
Competitive swimming became popular in the nineteenth century. The goal of competitive swimming is to constantly improve upon one’s time(s) in any given event. To be the best in a particular event means having the fastest time compared to other people in that event, though some professional swimmers who do not have a number one national or world ranking are known to be the best with regard to their technical skills in the water. Typically, an athlete goes through a cycle of training in which the body is overloaded with work in the beginning and middle segments of the cycle, and then the workload is decreased in the final stage as the swimmer approaches the competition in which he or she is to compete in. This final stage is often referred to as “shave and taper”; the swimmer has tapered down his or her work load to the point where he or she is able to perform at their optimal level, and then the swimmer shaves off all exposed hair and dead skin cells for the sake of reducing drag and having a sleeker and more hydrodynamic feel in the water.
Beyond mastering skills and achieving physical fitness, our swimmers will gain confidence, sportsmanship, discipline, commitment and an understanding that success results from hard work and goal setting. They will learn the value of being part of a team. Our aim is to make swimming an important and enjoyable part of our members’ lives.
Join our winning team of Famagusta Nautical Club, the Champion in swimming for 19 consecutive years in Cyprus.
For Swimming lessons for all ages, you can contact us at anytime.