Plyometric Program Design
When referring to the mode of plyometrics, I am referring to the body part or region that is targeted in the exercise(s).
Lower body plyometrics apply to nearly every single athletic and non-athletic movement done by the human body. Due to our fixture to the earth through gravity, our legs have much to benefit from a well-designed plyometric program which can then be applied to a number of athletic movements. Even those athletes that are not fixed to the earth (i.e. swimmers) can benefit greatly from a plyometric training program.
Although not as widely-used, upper body plyometric exercises also apply to many sports. More and more studies have shown that large, strong muscles are not necessarily the ideal solution for certain events such as throwing a baseball or a javelin. Look at Major League baseball pitchers for example, and you will see that it is not always the biggest, strongest guys that can throw the ball the hardest, but those that have the best form and have fast, explosive muscles.
Trunk plyometric exercises are generally used even less than upper body plyometrics, but that does not mean that they do not have their place in athletic training. Research has shown that trunk or core muscles do not have as much elastic properties as other areas of the body, so their training should be aimed at much smaller ranges of motion. Certain athletes can certainly benefit from trunk plyometrics however, such as those sports that require fast, explosive twisting motions such as baseball or golf.
Generally with aerobic or resistance exercises, intensity can vary based on the amount of weight, duration, etc. that is used. With plyometric exercise, intensity is generally gauged by the amount of stress placed on the skeleton, muscles, ligaments and joints. An exercise such as skipping or jogging is relatively low in intensity compared to something like a depth jump for example.
Other factors that vary the intensity:
Points of Contact - Single-leg plyometric drills are more intense than double-leg drills for example because there is more stressed placed on the single leg.
Speed - The faster an individual performs an exercise, the more stress is placed on the body.
Height of the Drill - The more vertical distance covered (higher the center of gravity), the greater the stress and force placed on the body is upon landing.
Body Weight - Obviously the more body weight an individual is carrying, the more stress is placed on the body's tissues.
When referring to frequency, I am referring to the number of plyometric workout sessions per week (usually 1-3) or more accurately, the amount of recovery time between sessions (at least 48-72 hours).
I cannot stress this enough when it comes to plyometric training. When using plyometrics as a performance-enhancing form of exercise, proper rest periods should be implemented in order to properly benefit from the program. Generally a 1:5-1:10 work to rest ratio should be applied to plyometric exercises as they are training the anaerobic power systems of the body.
Plyometric volume is usually measured by either the number of ground contacts or the distance traveled (for horizontal displacement plyometrics). The number of contacts per session usually starts as low as 80 (for beginners) and can progress up to as many as 140 for advanced or experienced athletes.
Research has shown that vertical jumping distance can improve in as little as 4 weeks of plyometric training, but generally, the NSCA recommends anywhere from 6-10 weeks of plyometric training for the greatest improvements.
Plyometrics should be considered resistance training as you are training the body to be as powerful as possible. As with any resistance training program, progressive overload should be implemented to ensure that the body is constantly being challenged and therefore continuing to grow and improve. As with any resistance training program however, as intensity increases, the volume should decrease to allow proper recovery and repair.
Plyometric programs should also have a proper warm-up to ensure the correct bodily systems are primed and ready for the stresses about to be placed on them. Dynamic movements should be used that are low in intensity, but mimic plyometric-type exercises to stretch and prepare the correct body parts. Examples of effective plyometric warm-up exercises include marching, jogging, skipping, agility footwork, and walking lunges.