The ability to get from point A to point B faster. Simple, yet complicated. I will try and explain the mechanics and physiology behind plyometrics.
There is a chemical, mechanical and neurological factor that influences the force and stiffness of a contracting muscle. It is the eccentric (lengthening) just before the rapid concentric (shortening) that will produce the greatest amount of force. This will enable you to build explosive power into your skeletal muscles. Another way of putting it is making your muscles move in the opposite direction of the desired force. So, if you were going to swing a baseball in the right-handed stance, what you would do is load to the backswing 6 inches just before the front swing. This movement is called the prestretch. Or, if you were going to jump up in the air, then bend 6 inches at the knees and hips just before exploding upwards. This is also called the prestretch. Keep in mind that you must have muscles that can stretch. Reason being is the muscles elasticity, or its ability to lengthen and increase in tension, known as the range of elasticity or strain, is directly proportionate to the ability of the tissue to resist forces and return to its original shape after releasing the load. Plyometric training plays on this elastic property factor.
By practicing certain plyometrics exercises, you stimulate changes in the neuromuscular system, which enhances the ability of the muscle to respond more quickly and powerfully to changes in muscle length. Make sure that the faster the transition from eccentric to concentric contraction, the greater muscular tension produced and therefore, the greater the muscle power produced. This equals more explosive movements. We suggest practicing movements and exercises that relate directly to your sport or activity. Youths under age 12 should not engage in many different types of plyometic exercises. Keep it basic and practice only a few per session. As your age increases, over 40 years of age, be careful as the ability of the nervous system, muscle and joint pliability and energy production decrease.
Train your brain to react more efficiently during the movements. Make sure to minimize the time lapse between eccentric and concentric contractions. There are actually two periods of delay to contend with. The first is the delay between the signal from your brain for muscle contraction and muscle activity. The second is between the appearance of muscle electric activity and the development of tension in the muscle called the EMD or electromechanical delay. The second delay is shorter in eccentric contractions. It supports the concept of producing the greatest amount of force in the least amount of time.
Foot placement is very important. To get the quickest release, you must maintain a locked ankle when landing on the ground. If you roll the foot from heel to toe or allowing movement in the ankle joint, you slow the response and dilute the force. The best way to land on the ground is to have your foot dorsiflexed (big toe pulled back) and 2/3 of your foot having ground contact upon landing while your weight is balanced on the front half of the foot.
There are several types of plyometrics exercises. We call them single and multiple responses. The goal as stated above is to accomplish high impulse landing and immediate take offs in succession. This would be like a basketball player getting a rebound and immediately putting the ball up for a basket. It might take him one rebound or several. Practice of this type of training will lead to continued success, which improves nerve-muscle reactions, explosiveness, quickness and the ability to generate great amounts of force in certain directions.
Another great concept in plyometic training involves complex training. Here we combine two exercises that are similar in pattern movement and fall into different forms of absolute or relative strength (speed not being a factor) and elastic (speed and rebounding ability). An example would be combining weights and plyometics. Take the “squatting” with weights and “jumping” onto blocks, the “pressing” of weights such as bench press and “passing” using a medicine ball and the “pulling” and “tossing”.
Now for the definitions of each type of plyometric exercise.
Bounds: Try and gain maximum horizontal distance. A term that is familiar is vertical leap or hops. Technically, it is any movement where you take off from one leg and land with the other.
Hops: Try to gain maximum height or distance with maximum rate of cyclic leg movement. Technically, it is any movement where you take off from one leg and land with the same leg.
Leaps: Try to gain maximum height along with maximum horizontal distance. You can perform it with both legs or just one leg.
Skips: Try to gain maximum height along with maximum horizontal distance while alternating a step hop or right to right step, then left to left step. Use multiple directions.
Ricochet: Try to gain rapid leg movements while minimizing vertical and horizontal distance. Try and increase the rate of execution.