Plyometrics, or
plyometric exercises are a category of exercise involving fast, explosive movements designed to give the athlete more power and explosive strength. The goal of any plyometric exercise is to train the muscle to contract at maximum intensity in the minimum amount of time, which is what power is; force divided by time.
Plyometrics are especially applied to athletes to help them take off from the gate faster, jump higher, throw faster, and hit harder.
As opposed to endurance training, or strength training, plyometrics trains power, which is a combination of strength and speed. As such, you would not work with a weight that would be your personal record in any exercise. Some examples of plyometric exercises are the two Olympic lifts- the snatch and the clean and jerk. Both of these involve explosive lifting movements to get the bar off the ground, and either straight up overhead, or to the chest followed by another explosive push to get the bar overhead. Many plyometric exercises involve throwing or swinging motions. A baseball pitch is an explosive movement, so a pitcher would benefit from practicing throwing a slightly heavier practice ball. Other plyometric exercises include jumping onto and off a raised platform, swinging a sledgehammer into a tire, hitting a heavy bag, throwing a medicine ball, or pulling a weighted sled over short distances for time. The blocking sled seen at football practices is an example of plyometric equipment. So is the weighted ring a batter puts around the bat while he takes his practice swings.
Care must be taken when taking on a plyometric regimen. The athlete should already be strong and in shape and one should definitely not go into a plyometric program without having been exercising regularly for several weeks. The main risks of plyometric exercise are the huge loads placed on the weak points of the body- namely the joints and tendons.