Frontal Resistance

      Resistance can be a swimmer's greatest ally or greatest downfall.  Frontal resistance occurs when the body rides too low in the water, producing a large surface area that pushes against the water in the direction opposite of forward motion.  Until the Australians began their first period of dominance in the 1950’s, swimmers thought the best way to reduce frontal resistance was to keep the body completely flat, riding on top of the water, in an effort to hydroplane.² According to Cecil Colwin, the most effective way to reduce frontal resistance is rolling the body from side to side with the stroke, known commonly as body roll.  Another cause of frontal resistance is lifting the head to high in the water while breathing, swimming or both.  Not only does the greater area of the face catch water, but it also causes the lower body to  sink.³   It is generally accepted that the first step in becoming a good swimmer is dealing with the effects of frontal resistance. 

          Skin Friction

     Skin friction is the kinetic friction of the swimmer's skin and suit with the water.  This can be easily dealt with a couple of ways.   The most popular method is to shave off all visible body hair, occasionally even the eyebrows, and cover the body with a generous layer of lotion.  When a swimmer shaves their body hair they decreases the surface area of their skin.  The velocity of the water at the point of contact is 0 m/s.  The lower the surface area the less water there is traveling at 0 m/s.²   This is usually reserved for important races, for example Lenny Krayzelburg did not shave in the Olympics until the final race of his events.  Megan Quann did not even shave for the U.S. Olympic Trials, saving it for the 2000 Olympics.  The effectiveness of shaving and lotioning is still under debate.  James Counsilman believes that the results are more because of tapering (a gradual decrease of distances and an increase in concentration on technique in practice) before a competition and the added psychological influence of the skin being more sensitive and smooth.  There are also studies that show shaving can take up to one second off a swimmer's time for every fifty meters.

      Another way swimmers reduce skin friction is through the use of compression and body suits.  These suits are designed to reduce muscle wobble and most of the friction caused by the suit.  The introduction of body suits at the 2000 Olympic trials produced a new way to reduce skin friction.  The manufacturers of these suits claim the specially designed suits reduce almost all surface friction with specially treated fabric and seams.  The effect these suits will have on the swimming world will not be determined until much more research can be done.

        Eddy Resistance

     Eddy resistance is the last form of resistance that is important.  This is caused by poor stroke technique and riding too low in the water. (see picture)  Water is unable to fill in instantly behind the swimmer, causing them to pull water and air bubbles along with them.  Eddy resistance is also how a swimmer moves through the water.   When a swimmer's hand enters the water a bound vortex forms around the swimmers hand and arm.  In the distance events the vortex is shed only as the arm exits the water.  In a sprint event the experienced swimmer sheds a vortex every time the hand changes direction along the lateral axis, usually two to three times per stroke.  The multiple shed vortexes allow the sprinter to accelerate throughout the pull while still maintaining an adequate amount of efficiency.  A shed vortex is a form of kinetic energy that occurs during an increase in velocity or a dramatic change in direction.  When it is shed out of phase the energy is wasted obtaining another bound vortex.²   Bound vortexes formed around the hand, arm, feet, and legs create the resistance in the water that the swimmer uses to propel them forward. 

A swimmer producing all three forms of resistance.
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