It was in the early 1970's that plyometrics was introduced to the American athletes. Originally used by the Soviet Union to train their athletes for strength and speed, it's valuable benefits and uses were not picked up on by the other countries till much later. Unfortunately, plyometrics were and still are not always used in the correct manner such as the Russians had first used it. They used it with their other training techniquesso it was not overused but it did give them exellent results.
Shock training is another name for plyometrics. Shock training makes use of the stretch shortening cycle, which is the active stretch of a muscle followed by a immediate shortening. These are a great benefit to the lower body for explosive power training.
Before starting any plyometric or shock training you should already have a good base of strength already established. You should have the ability to squat at least 1.5 times your body weight. The shock from landing on your feet when jumping doing plyometrics is stressful to your legs so having enough strength will help prevent injury. If you want to try doing any plyometrics before you reach the 1.5 times body weight squat, You must keep the jumps from boxes to a very low level. It would be best to be no higher than your current jump height.
Two popular exercises are the Depth Jump and Drop Jump. The box height to use for depth jumps should be low enough to allow for a good high jump immediately after you step to the ground. Jump out from the box about the same distance as the box is high. For a drop jump you just want to stop where you land, do not jump up again. Landing with knees bent will absorb the shock.
5 to 8 reps per set and 3 to 5 sets is about what you should do. Rest up to 30 seconds between reps and up to 10 minutes between sets. It would be best to jump onto a soft surface such as grass or some kind of pad.
For more info go to You Can Jump Higher to discover how to improve your vertical jump skills. Tim Archbold's interests are Fitness Training and Health.