The training programs for swimmers 100 m freestyle must be directed to enhance the physical abilities of this competition, especially muscle strength of various kinds according to the nature of external resistance faced by the swimmer in the water and for a relatively long time, so the researchers resorted to preparing exercises with resistances and against the direction of movement of the swimmer in order to mobilize and activate additional motor units to create a state of adaptation and Alastharain these units to produce Fast kinetic action to overcome external resistances represented by the aquatic environment, improve biomechanical variables and achievement.