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  Wave drag is present at the interface of the water and the air, as the swimmer pushes through water and the drag is greatest when the wave distance equals the length of the body. To reduce wave drag, Blazevich (2012, p. 158) suggests increasing the effective body length by stretching the arm in front of the body at the end of the recovery phase (before propulsion). The arm may also help in dispersing the oncoming flow of water, reducing the wave build-up hitting the surface area of the swimmer’s head and therefore reducing wave drag.

   Wave drag: waves build up at the front of 

   the body during swimming, creating drag.

Form drag is the drag associated with the surface area and the shape of the swimmer. This form of drag can be reduced by keeping the surface area that is exposed to the water at a minimum. The head should be kept down and the swimmer should be conscious that the larger the kick the larger the frontal surface area becomes. Additionally, keeping the waist high and the legs aligned with the waist minimises the pitch angle, therefore reducing drag and maximising speed.

Form drag: having the body aligned during the

 swim reduces the surface area of the body and therefore 

reduces form drag. When the body is unaligned the 

surface area is greater, therefore creating more drag. 

  Surface drag is caused by the friction of a fluid on the surface of an object. This form of drag in swimming is typically caused by the material and size of the swimmers and the presence of body hair. Hairless skin has a lower friction coefficient than Lycra or cotton in water and traditional, yet still widely popular, drag-reducing techniques have involved shaving the limbs and head in conjunction with wearing a swimsuit that covers the minimum amount of the torso (Blazevich, 2012, p. 163). While high performance swimsuits are widely popular in professional swimming their use raises questions about fairness in the pool and is dictated by strict guidelines as outlined by FINA - the international authority on swimming. 

                                                                               

   This short video shows how swim wear company Speedo has incorporated biomechanical principles related to drag to create a new swim suit that meets international guidelines.   

  However, drag is not always a bad thing. Blazevich (2012, p.169) writes that the force of propulsion into the freestyle turn can be harnessed by increasing the surface area of the hand and arm and therefore increasing drag. This is achieved by a straight arm path and slightly spread fingers. Spread fingers increases surface area as the flow of water is impeded as the volume of water passing through the hand is increased. Additionally, flexing the elbow and wrist downwards in the propulsive phase of the stroke, as opposed to keeping a straight arm, ensures the horizontal forces are optimised, the greatest amount of water is 'caught' or 'dragged' and propulsion is maximised.