For some time now, plyometric training has been used to help athletes reach top physical condition in a variety of sports. Combined with a good strength training program, plyometrics have shown to be one of the most effective methods for improving explosive power.
What exactly is plyometric training?
A plyometric is an exercise that enables a muscle or a group of muscles to reach their maximum force in the shortest time possible. All plyometrics consist of three phases. Phase one is the eccentric contraction, also known as the pre-stretch in which the muscle is stretched and elastic energy is generated and stored. Phase two is the time between the eccentric phase and concentric phase, also referred to as amortization, which should be very quick. The shorter the amortization phase, the more powerful the following concentric contraction will be. The final phase is the concentric phase which is the actual muscle contraction or shortening. These three phases together are known as the Stretch-Shortening Cycle.
An easy way of demonstrating the stretch-shortening cycle is to have an athlete perform two vertical jumps. During the first jump when the athlete bends his/her knees and hips (eccentric phase), have them pause for about five seconds before jumping as high as they can (concentric phase). This long delay increases the amortization phase, burning all the stored elastic energy. In the second jump, instruct your athlete to make the transition from eccentric to concentric as fast as possible. The second jump will be higher, demonstrating that the shorter amortization phase, the more powerful the contraction.
Frequency, Volume, and Intensity?
Now that you have had a brief background on the physiology of plyometrics, here are some tips for designing a program.
Normally, 2-3 sessions per week of plyometrics can be performed. It is not recommended that plyometric training be scheduled the day after heavy weight training. Alternating upper and lower body plyometrics with upper and lower body strength training can solve this problem.
The volume of plyometrics refers to the number of repetitions in each session. For example, with lower body plyos, any ground contact is considered a repetition. Athletes just introduced to plyometrics should have no more than 100 ground contacts in a session. Intermediate athletes should be between 100-120 and Advanced athletes should be around 140 contacts.
Intensity of plyometrics depends on each different exercise. Depth jumps are considered some of the highest when it comes to intensity whereas skipping is classified as one of the lowest. Intensity in a plyometric training program should be based on each athletes abilities and should gradually be increased from low to higher intensity.
What else do I need to know?
As with any workout, a proper warm-up is important and should not be blown off. Not being properly warmed up can lead to serious injuries. Plyometrics should be performed after the warm-up and before any weight training, when the athlete is still fresh. Knowledge of proper technique for plyometrics is needed before instructing athletes to perform them in order to ensure there are no injuries.
For more information on designing a proper plyometric program for an athlete, contact your local FAST® facility, or visit www.fast-training.com.