What, if any, are the Differences Between Plyometric and Jumping Activities?
While commonly used to define the same thing, plyometrics and jumping exercises are actually not necessarily the same thing and correct classification of the two training modalities has implications for designing training sessions and training units. Strictly speaking, plyometric activity is one which elicits the stretch reflex. This typically happens when an eccentric contraction is immediately followed by a concentric contraction, resulting in a greater force than would be possible to produce voluntarily. This definition has two important points. First, plyometric activity does not have to be confined to only jumping or lower body activity, and secondly, not all jumping activities are plyometric in nature because not all jumping exercises elicit the stretch reflex. For example, rocket jumps have an amortization phase that is far too long and slow to elicit the stretch reflex, thus they are not a truly plyometric activity. Another example is static-dynamic jumps which eliminate the stretch reflex because the static phase resets the stretch-reflex response. The distinction between plyometric and jumping exercises is important in the design of training sessions and training units. Because of the stretch-reflex response, plyometric activities have the potential place a greater training load on the CNS than non-plyometric activity. Likewise, jumping exercises that are not plyometric in nature may be more intensive on the muscular system due to the need to overcome inertia with concentric strength alone. This distinction is important when attempting to make all units within a training session or training unit compatible and complimentary.
