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| At Extreme Strength We Use Plyometrics to Strengthen the Mind and the Body. Plyometrics may be new to some people... For Speed, Power, and Agility They are Second to None! Plyometrics is a type of exercise training designed to produce fast, powerful movements, and improve the functions of the nervous system, generally for the purpose of improving performance in a specific sport. Plyometric movements, in which a muscle is loaded and then contracted in rapid sequence, use the strength, elasticity and innervation of muscle and surrounding tissues to jump higher, run faster, throw farther, or hit harder, depending on the desired training goal. Plyometrics is used to increase the speed or force of muscular contractions, often with the goal of increasing the height of a jump. Plyometric training involves practicing plyometric movements to toughen tissues and train nerve cells to stimulate a specific pattern of muscle contraction so the muscle generates as strong a contraction as possible in the shortest amount of time. A plyometric contraction involves first a rapid muscle lengthening movement, followed by a short resting phase, then an explosive muscle shortening movement, which enables muscles to work together in doing the particular motion. Plyometric training engages the myostatic-reflex, which is the automatic contraction of muscles when their stretch nerve receptors are stimulated. Plyometric exercises use explosive movements to develop muscular power. Plyometric training acts on the nerves, muscles, and tendons to increase an athlete's power output without necessarily increasing their maximum strength. In addition to the elastic-recoil of the musculotendonous system there is a neurological component. The stretch shortening cycle affects the sensory response of the muscle spindles and golgi tendon organs(GTO). It is believed that during plyometric exercise, the excitatory threshold of the GTO's is increased, making them less likely to send signals to limit force production when the muscle has increased tension. This facilitates greater contraction force than normal strength or power exercise, and thus greater training ability. The muscle spindles are involved in the stretch reflex and are triggered by rapid lengthening of the muscle as well as absolute length. At the end of the rapid eccentric contraction, the muscle has reached a great length at a high velocity. This may cause the muscle spindle to enact a powerful stretch reflex, further enhancing the power of the following concentric contraction. The muscle spindle's sensitivity to velocity is another reason why the amortisation phase must be brief for a plyometric effect. A longer term neurological component involves training the muscles to contract more quickly and powerfully by altering the timing and firing rates of the motor units. During a normal contraction, motor units peak in a de-synchronized fashion until tetany is reached. Plyometric training conditions the neurons to contract with a single powerful surge rather than several disorganized contractions. The result is a stronger, faster contraction allowing a heavy load (such as the body) to be moved quickly and forcefully. Repeated use of plyometric exercises will gradually increase the efficiency of neuromuscular connections between brain and muscle. However, a fine balance must be used if one wishes to build strength and power through plyometrics. It is often recommended that plyometric repetitions be no higher than 75-100 reps. Also, training with plyometric exercises more than three or four times per week can cause muscular degeneration if proper nutrition and rest are not taken into account.[1] - Brooks, G.A, Fahey, T.D. & White, T.P. (1996). Exercise Physiology: Human Bioenergetics and Its Applications. (2nd ed.). Mountain View, California: Mayfield Publishing Co.
- Chu, D. (1998). Jumping into plyometrics (2nd ed.). Champaign, Illinois: Human Kinetics.
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