Training Explosiveness with Plyometrics

By Nunzio Signore (BA, CSCS, CPT, NASM, FMS)


When most of us think of what comprises a great strength training program, we think of training force production.  While this is crucial to enhance performance, the dissipation (absorption) of force is vital not only to performance, but for reducing the risk of injury as well.  We can’t talk about either force production or dissipation without talking about plyometrics. Numerous studies have shown that performing plyometric training:

  • Improves soft tissue quality
  • Helps reduce the risk of injury
  • Increases throwing velocity

The main goals of plyometrics are to decrease the time going from the eccentric to concentric phase or to gradually introduce back load to the tissue while rehabbing an injury.  There are three different phases to plyometrics:

1. Eccentric Phase – This is where the muscle is stretched to load the upcoming concentric phase, much like loading up a slingshot or a squat in preparation to jump.Slide2

2. Amortization Phase – This is the transition from the eccentric phase to the concentric phase. The purpose of performing pure plyometrics is to decrease the time spent in this phase in order to create more explosiveness in the concentric phase. The shorter time spent in this phase, the better use of the Stretch Shortening Cycle (SSC). The longer we stay in this phase, the more energy is lost through the dissipation of heat, resulting in a less powerful concentric phase.


For a pitcher this happens coming out of low positions of the delivery such as the glute load while beginning leg drive and posting up after first foot strike to ball release.

3. Concentric Phase – This is the end-result (force) produced from the previous 2 phases.

Not all power development drills utilize all the principles that plyometrics supply.  Many times, the Eccentric phase and the transfer of force (amortization phase) is left out.


(OH Med Ball Throw)

(Shovel Pass)

While this is fine early in the off-season when the goal is to train strength and force production, later in the off-season when we’re putting it all together, it becomes necessary to produce that force quicker to more accurately train game-time speed.  When talking about med ball work, this involves a more bouncier ball to force the athlete to absorb what is coming back (eccentric), and quickly transfer the force concentrically back out.

(Reactive OH Med Ball)

(Reactive Shovel Pass)

Rehab – Plyometrics are also an equally important part of any well-structured rehabilitation program as well. We give our guys coming off of an injury or returning from PT, a progressive plyometric program approx. one month prior to beginning their throwing programs. This helps get back some “baseline” power development as well as getting tissue quality back in the game.  Whether you’re in-season off-season or coming back from an injury, plyometric training should be included in the program design. Like anything, it’s just all about the dosage you prescribe.

Remember, don’t just train the output, train the input as well.

See ya’ in the gym…

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