Plyometrics are an essential component of any strength and conditioning program where speed, power and explosive capabilities are important. In order to prescribe plyometric training correctly it is important to have an understanding of the physiological demands the requisite exercises place upon the human body. It is all based upon the principle of the Stretch-Shortening Cycle (SSC) which composes of 3 phases including:
-An eccentric phase or stretch on the muscle
-An isometric transitional period (amortization phase) on landing
-An explosive concentric action driving the movement
Therefore, for an exercise to be plyometric it must involve all three elements of the SSC. Minimal time in the amortization period allows loss of elastic energy stored from the eccentric stretch to be a minimum, which leads to amaximal force production.
There are 4 main groups of plyometrics; jumps, hops, bounds and shock movements (Allerheiligen and Rogers, 1995). Plyometrics must be attempted at a basic level to introduce the body into the movement, building into it, but they should not be attempted by athletes with muscle imbalances or injury. When starting plyometrics, low-load exercises are best to start with such as basic on the spot jumps, developing up the plyometric pyramid into top end exercises such as drop jumps. But these must not be attempted without coaching or support. Plyometrics should be developed in all planes of motion as well as bilateral and unilateral, but again fundamentals must be mastered before moving on.
Plyometrics involve huge amounts of neuromuscular work, therefore it is crucial to do them early in a training session if combining with weights or speed work to prevent training fatigued, leading to injury. Over the course of a periodised program, the athlete would incorporate these exercises throughout the season, with higher importance during power development training in preseason. Although the obvious example of plyometric application to sport is within the Jump events within athletics, plyometrics is prominent in nearly all sports, such as jumping for a header in football, changing direction in netball and even down to running. Therefore all athletes should look to incorporate plyometrics into their training.