Let the Water-Down Begin!

Almost without exception, every 'sport-performance training center' and youth sporting association in North America both markets and incorporates some degree of plyometric conditioning into the routines of the athletes they manage. More often than not, the trainer or coach prescribes an unintelligible series of jumping exercises and can be seen either holding a clipboard and a stop watch as they count and record the number of jumps or foot contacts a young athlete makes within a certain period of time, or barking out commands to 'jump higher'. Plyometric training has become such a 'catch-phrase' in the vernacular of trainers and coaches that it is often marketed as a sole measure of distinction for a training facility or individual coach/trainer. Do you know how many sporting clubs, for instance, have told me that they would love to have their athletes train at my facility, but their Director of Coaching has a 'plyometric class' that he/she hosts every week and that's all the conditioning they need?

Plyometric training has become watered down in North America to such a level that now even basic health clubs have introduced 'plyometric jumps' into their general group exercise classes as a means of achieving some measure of 'high intensity' training. Jumping and then abruptly stopping and holding a fixed position, jumping and then jumping again after a cursory pause or being taken through a series of jumping exercises without being taught proper execution of either the jumping or landing phases respectively are simply gross misappropriations of what plyometric training is or how it should be applied.

Origins of the 'Plyometric'

Originally called the 'shock method', this type of training is meant to increase the speed-strength aptitude of a given athlete (speed-strength is the ability to perform a quick movement which is either unloaded or against a minimal external resistance). A key ingredient to shock training is a short amortization phase, which is the time between the conclusion of the eccentric or braking phase of a jump or movement and the commencement of the concentric or acceleration phase (it is also often defined as the time from the beginning of the eccentric action to the beginning of the concentric action). Shock training is based on the creation of very quick eccentric and explosive actions during which stored elastic energy is released from the connective tissues housed within the series elastic components of a given muscle complex. Within the muscle complex, soft tissue is divided into a contractile system and a non-contractile system; the non-contractile system encompasses connective tissue including tendons, ligaments and capsules. This system subdivides again into the parallel elastic component, which includes fascia, and the series elastic component, which includes tendons. Ballistic stretching or fast, reactive motion has a greater impact in the series elastic component, thus its involvement in plyometric or shock training.

...This Stuff Shouldn't Be 'Hard'

Of important note with respect to execution and prescription is that if the transfer from braking to acceleration takes longer than 0.2 seconds, than the activity would not fall under the parameters of shock or plyometric training. This is a crucial point considering that many trainers and coaches use 'plyometric' training to such an extreme level (i.e. increased number of reps and timed sets or decreased amount of rest between sets) that young athletes are simply not able to produce quick explosive and eccentric actions. Having said that, speed-strength is not being produced or improved. It is exceedingly decisive to remember that when training young athletes, the goal should not be to create as physically difficult a training session as possible. In fact, as with shock or plyometric training, the more physically challenging the exercise or training session is, the less you are actually improving the speed-strength capacity of the athlete -- which is the reason you were offering plyometrics to begin with!