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We talk a lot about the aerodynamics of cycling, and countless products are designed to help us cut through the wind. But what about the hydrodynamics of swimming? Water is 784 times denser than air, and in order to achieve your best swim splits, you have to move through it as efficiently as possible.
Frontal resistance is the drag produced by the surface area of your body position in the water. A well-balanced swimmer will present only the necessary amount of surface area (just the top of his head and shoulders) while an imbalanced swimmer, with hips and legs dragging low in the water, will present a much larger surface area. Minimizing frontal resistance is the first and easiest way to improving speed through the water.
For a long-distance swimmer, reducing drag in the water takes priority over producing power. If a speedboat and a barge are in the water with identical motors, which one will move faster and farther? By improving body position along the surface of the water, a swimmer can move through the water at faster speeds with the same power output.
What’s Causing You to Slow Down
Hydrodynamic drag is caused by more than just low hips and legs. Swimmers that are balanced in the water can cause extra resistance in other ways:
Head position: Keep the head in line with the spine so the water cuts right across the center of the top. A head held too low or high in the water will create additional drag from the upper back or chest.
Kick: Your kick should be short and compact to prevent excess drag. A scissor kick out to the side or an extra large kick will push the legs out from behind the body and create more resistance.
Hand entry: The arm should be almost fully extended when it enters the water. Pushing the hand forward underwater with a high elbow creates additional resistance on the vertical forearm.
Body sway: Any lateral body movement in the water will also increase drag. Keep the head, shoulders, hips and feet in a straight line to prevent wiggling in the water.
How to Eliminate Drag
Finding balance in the water does not come naturally because a body’s center of gravity is near the hips, while the chest contains the buoyant lungs. The simple act of floating can indicate if a swimmer is struggling to maintain an efficient body position while swimming. A head-on underwater video shot is also a good way to evaluate where a swimmer is creating excess surface area through each stroke cycle. When trying to be more efficient in the water, the key is to relax and stop fighting the water. Instead, use the water to stay afloat so all expended energies can be directed to forward movement.