Wednesday, April 1, 2009

Developing a Plyometric System

Plyometrics: Connecting the Weight Room to the Field

Plyometrics play an essential role in the Athletes' Performance Training System (APTS) and are critical to the success of our athletes. Plyometric training is used for Performance Enhancement and Injury Prevention with a focus on high quality movement patterns. The ability to translate the strength and speed developed in the weight room to the field is paramount for our athletes. One of the primary ways we do this is through the proper implementation and execution of plyometrics. Within the APTS plyometrics will follow movement preparation and precede our movement skill session. This session will focus on specific movements, directions and strength-power qualities (i.e. movement initiation) based on the ability of the athlete in terms of that day’s movement session (ex. Linear focused plyometric session will precede a linear focused movement skills session). It should be noted that this session focuses on high quality movement patterns with an emphasis on maximal power production and rate of force development in an effort to potentiate the movement patterns used during the movement skills session.

Plyometrics may be defined as any movement that utilizes the Stretch-Shortening Cycle (SSC). The SSC can be defined as a concentric contraction that has been preceded immediately by an eccentric contraction. It is during the eccentric contraction or “pre-load” that we see multiple neuromuscular actions that facilitate greater force being produced during the concentric phase of a given movement. These actions include: (1) Increased time to develop force due to the eccentric and isometric “Pre-Load”, (2) Increased muscle stiffness and therefore the ability to store and release elastic energy during the concentric phase, (3) Potentiation of the Stretch Reflex due to the rapid lengthening seen during the eccentric phase of the motion. These actions result in greater force per unit of time (i.e. Rate of Force Production) being produced during the concentric phase. Researchers are still debating which variable is most responsible for the increase in force seen during the concentric phase and arguably these variables may be emphasized differently based on the plyometric movement being used (ex. Countermovement Jump vs. Depth Jump). For a great review on the SSC and the role of elasticity in human movement please see Wilson et al.

When designing a plyometric progression we must respect the demand placed on the nervous system and the tissue of the body. For these reasons we will use simple stability based progressions on the front side of a training program and move into more complex and power oriented progressions as movement mastery is achieved. Additionally, we will look very closely at not only the movement progressions, but also the volume of contacts used in a session and a week. Within the APTS we use plyometrics as a potentiator for the movement skill session and primarily focus on producing optimal power with every repetition executed. From a training adaptation standpoint we are looking for the following results: Improved landing and take-off quality; increased tissue tolerance and muscle stiffness (i.e. elasticity); and decreased amortization (time from the onset of the eccentric phase to the concentric phase) and coupling times (time from the end of the eccentric phase to the beginning of the concentric phase). It can be noted that if the focus is on power endurance, or the use plyometrics for work capacity, then you would see those executed after the movement skill session or directly integrated into an auxiliary circuit within our strength training component.

Plyometric Variables:

Movement Type:

· Jump: 2 Leg take-off with a 2 Leg landing
· Hop: 1 Leg take-off with the same 1 Leg landing
· Bound: 1 Leg take-off with the opposite 1 Leg landing
Movement Direction:
· Primary: Linear, Lateral or Rotational
· Emphasis: Vertical and/or Horizontal Displacement
Movement Initiation Progression-Continuum:

Drop Squat/Hop: From a standing position drop into desired landing position (ex. 1-Leg vs. 2-Leg Landing) with the emphasis being placed on movement mechanics. Strength-Power Quality: Low eccentric demand with landing focus

Non-Countermovement (NCM) to Box (3-12in): Not a true plyometric as there is at least a 2s pause prior to executing the concentric phase of the motion and therefore does not optimally use the SSC.
Strength-Power Quality: Contractile Focus (i.e. Starting Strength-Power) with moderate eccentric demand

Countermovement (CM) to Box (3-12in): True plyometric that uses an eccentric pre-load prior to quickly transitioning into the concentric phase of the motion.
Strength-Power Quality: Explosive Strength-Power focus with moderate-high eccentric demand

NCM on Ground
Strength-Power Quality:
Contractile Strength-Power (i.e. Starting Strength-Power) with moderate eccentric demand

CM on Ground
Strength-Power Quality:
Explosive Strength-Power focus with moderate-high eccentric demand

Double Contact (Stability): This initiation requires a person to set at the specific joint angles that they wish to take-off from and subsequently attack the ground to initiate a forceful SSC.
Strength-Power Quality: Contractile-reactive Strength-Power with high eccentric demand

Double Contact (Continuous): This initiation is executed in the same manner as the previous, but instead of stabilizing after each movement the person will land then immediately attack the ground to continue motion in the desired direction.
Strength-Power Quality: Reactive Strength-Power/power with high eccentric demand

Continuous: This initiation is executed with continuous contacts using the desired movements and directions.
Strength-Power Quality: Reactive Strength-Power with very high eccentric demand

Additional Load or Depth Work: To increase the eccentric demand a person can add load to the body or require that the person drop from a specific height prior to executing the desired movement. Both of these techniques are highly advanced and it can be recommended that you initially use simple movements, directions and initiation choices (ex. Linear-Vertical NCM-Jump w/ 20Lb weight vest).
Strength-Power Quality: Depends on movement initiation with extreme eccentric demand


From a cueing standpoint we will focus on hip, knee and ankle alignment in addition to proper trunk and arm action. Some example cues include: “Lock your ankle and land on ball of foot”; “Unlock your hips and sit behind your knee”; “Stomach tight when landing”; “Arms drive the hips up and pull the hips down”; “Drive your hips up through your chest”. We try to find the cue that maximizes results and minimizes paralysis through analysis.

As a general rule everyone will start with the base level progressions and move to the next level once they have reached mastery. This allows everyone within a group to learn the movements at the same time, but progress at an individualized level. A further note is that the initiations used are not only a progression, but also represent a continuum. For example, an NFL lineman may be at the level where they can use a continuous initiation, but they still need starting strength-power for there sport and therefore we would still want to use a NCM initiation within their plyometric program. Manage risk and maximize benefits while understanding that quality is more important than quantity when it comes to developing a seamlessly integrated plyometric progression.

Recommended Reading:
Aagaard, P., E.B. Simonsen, J.L. Andersen, P. Magnusson, and P. Dyhre-Poulsen. Increased rate of force development and neural drive of human skeletal muscle following resistance training. J Appl Physiol. 93:1318-1326, 2002.


McGuigan, M.R., T.L. Doyle, M. Newton, D.J. Edwards, S. Nimphius, and R.U. Newton. Eccentric utilization ratio: effect of sport and phase of training. J Strength Cond Res. 20:992-995, 2006.


Siff, M.C. Supertraining. Denver, CO: Supertraining Institute, 2003.


Stone, M.H., M. Stone, and W.A. Sands. Principles and Practice of Resistance training. Champaign, IL: Human Kinetics, 2007.


Wilson, J.M., and E.P. Flanagan. The role of elastic energy in activities with high force and power requirements: a brief review. J Strength Cond Res. 22:1705-1715, 2008.


Zatsiorsky, V.M., and W.J. Kraemer. Science and Practice of Strength Training. Champaign, IL: Human Kinetics, 2006.

Listen to this podcast on www.strengtcoachpodcast.com

Nick Winkelman CSCS, *D; NSCA-CPT, *D
Education Manger/ Performance Specialist
Athletes' Performance (Tempe, AZ)
nwinkelman@athletesperformance.com
www.athletesperformance.com/education

5 comments:

  1. This is outstanding stuff! Thanks for posting and your interview series on the StrengthCoach podcasts.

    ReplyDelete
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  3. 1st:
    After only reading a few of your posts, I have become a fan and your blog has moved its way up my frequently read blogs. :-) Thanks for the info.

    2nd:
    I have some questions for your classifications.
    a-would you consider a split jump a bound?
    b-would you consider and alternating split jump or a scissor jump a bound?
    c-how would you classify a double leg take-off to a single leg landing?
    d-can you give a couple examples of your rotational plyometrics?

    Thanks in advance.

    ReplyDelete
  4. correction:
    a-would you consider a split jump a hop?

    ReplyDelete
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