that the athlete not overdo using the shock plyometric method. Doing so will lead to great fatigue, and, according to Verkhoshansky, sleep disturbances. Athletes have great difficulty sleeping well if they execute too many depth jumps. This indicates that athletes must be well-prepared physically before doing this type of training. Technique of jumping is also very important when executing plyometric exercises. In essence, the athlete goes into a slight squat (crouch) upon landing in which the hip, knee, and ankle joints flex. The takeoff or jump upward is executed in a sequence initiated by hip-joint extension followed by knee-joint extension which begins during the hip-joint extension. As the knee-joint extension is taking place, ankle-joint extension begins and is the only action that occurs as the takeoff (breaking contact with the ground) takes place. All three actions contribute force to the upward jump, but the knee-joint extension is the major contributor. As simple jumping The most common type of plyometrics used in the United States is simple and relatively easy jump exercises executed with little regard to execution time. These jumps are effective for athletes who execute skills in their sport that do not require explosive type muscular contractions. An example is long-distance running in which the runners execute repeat actions of 20 to 30 consecutive jumps and other cyclic-type activities such as leaping for multiple repetitions. Such plyometric jumps are also used as a warm-up for doing explosive plyometric jumps and for initial preparation of the muscles prior to undertaking exercises such as depth jumps. In essence, they are effective in the early stages of learning how to do plyometric exercises and for preparing the muscles for explosive or quick jumps. These jumps are similar to those done by youngsters in the playground or in neighborhood games and as such, do not require additional preparation. Athletes, regardless of their level of expertise, can undertake such jumps in the initial stages of training. When athletes who have been doing plyometrics without regard to time of execution first attempt to execute explosive plyometrics, they often fail because the time of execution is too long. This occurs quite often in the depth jump. The athlete usually sinks (drops) too low which takes too long to make the transition from the eccentric to the concentric contraction. As a result, the exercise becomes a jump-strength exercise and not a true plyometric one. Jump technique remains