A Primer on Plyometrics

Introduction
Plyometric Basics
Lower Extremity Plyometrics
Upper Extremity Plyometrics
Programming
Conclusion

Introduction

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Plyometric exercises are an extremely effective method of training the body for explosive power.  Many trainees will use plyometrics to increase jumping efficacy, but these techniques can be applied to increase explosiveness in upper body movements, as well.  The benefits of incorporating plyometric exercise are touted for most sports, particularly skiing, jumping sports (e.g. basketball, volleyball), and track and field.  The application of increased power and explosiveness in my discipline of choice, parkour, should be very apparent as jumping and explosive pushing dominate most of parkour’s dynamic movements.

There is a need for clarification, however, on how to properly incorporate plyometrics into one’s workout routine.  This need exists because, in my experience, when plyometrics are recommended to most trainees there are usually a lot of questions that follow.  What are plyometrics?  How do they work?  How do I effectively make them part of my exercise routine?

None of the information in this article is new but the content has been laid out to make understanding and applying this information much easier.  By the end of this article, you should be very familiar with the concepts of plyometric training and how they can be applied to a variety of movements in a comprehensive training program.

Before reading further, do understand that some of the recommendations I make may not be consistent with information found elsewhere.  Some sources claim that lower extremity plyometrics should be avoided until the trainee can squat 150% of their bodyweight.  I think that is a bit excessive since most people can still get a major benefit of low-impact plyometrics while having no experience with the squat.  More specifically, the NSCA recommends that one be able to perform a 60% bodyweight squat before starting a program involving lower extremity plyometrics (1).  This is a modest recommendation with which I would be in agreement.

It is quite common that most trainees cannot or will not train weighted squats due to lack of proper instruction or equipment.  I would suggest that if one has little or no experience with the squat and/or cannot squat at least 60% of their body weight then all plyometrics should be kept low impact, at most.  In addition, use your head and validate your sources (i.e., this article) with other sources that are available.

Plyometric Basics

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Plyometric exercises take advantage of a muscle’s natural tendency to want to shorten after being stretched.  This is a powerful phenomenon known as the stretch-shorten cycle or the stretch-shorten reflex. There are a couple of important properties of skeletal muscles that make this possible.

Firstly, muscles have elastic properties that make them like springs.  If you take a muscle (such as a piece of chicken, for example) and pull on it gently, it will return back to its original shape.  The more forceful the pull, the more quickly the muscle will snap back to its original shape.  Muscles in the human body act in the same way. Plyometrics look to harness the lengthening of the muscle and synchronize the resulting “snap-back” with actual muscle contractions that make the shortening of the muscle faster and more forceful.  This results in a stronger push and a higher jump.

Secondly, the central nervous system (brain and spinal cord) is constantly receiving information from the muscles regarding how much they are stretched.  When muscles lengthen too quickly, the nervous system senses the sudden change in length and sends a signal back to the muscle initiating a violent overcompensating contraction.  This is seen when you go to the doctor’s office and the doctor tests your reflexes.  When he hits your patellar tendon with a mallet it causes the quadriceps (collection of thigh muscles)  to stretch.  The spinal cord detects this rapid stretch and causes the quadriceps to react with a forceful contraction that causes your knee to shoot out in front of you involuntarily.  You can reproduce this effect in several other locations on the body where a large tendon is exposed, such as the Achilles’  tendon on the back of the ankle.  Here, the mallet causes the gastrocnemius (calf muscle) to stretch and the spinal cord sends a signal back telling the gastrocnemius to contract forcefully.  This causes your toes to point quickly.

Pair these forceful contractions from your reflexes with the fact that your muscles naturally “snap back” after lengthening and you can train for some pretty impressive feats of power.  Since plyometrics train muscles to harness the stretch-shorten reflex from the nervous system, even someone with a high level of strength can see massive gains from a simple plyometrics program.

There is one small side note that is worth mentioning as it confuses many trainees that are new to plyometrics.  Most people think it is necessary to go down into a full range of motion, for example a deep squat, in order to fully take advantage of plyometric training.  This is not the case.

Full range of motion training can be beneficial, even in a program that is focusing on explosiveness.  The highest degree of power output, however, is harnessed from a partial range of motion.  This is because there is a limit to how much the muscle can stretch before losing the ability to contract more forcefully.  For example, if you were to go into a deep, full range of motion squat before your jump then your hamstrings would be very stretched.  Based on the statements above, this would seem great – more stretch turns into more “snap-back.”  While this is true, the elasticity of the muscle is not as important as the stretch-shorten reflex.

Firstly, in this example, a deep squat is very slow in comparison to a quick dip down and drive upwards.  The speed of the stretch is a main reason why the stretch-shorten reflexes occur.  Since the stretch is much slower, the reflex reaction doesn’t even occur.  Also, going into a deep squat causes the muscle to stretch a lot, which, in turn, forces the muscle to leave a state known as optimal length. The further you deviate from optimal length the harder it is to cause a contraction.  When the length of a muscle gets too long or short it becomes very difficult for the muscle to generate more force.

In short, explosive performance increases most easily by using an abbreviated range of motion in plyometrics training.  Using an abbreviated range of motion allows the trainee to generate the most power and increase performance effectively.  If the goal is a comprehensive general preparedness and strengthening through the whole range of motion, then a full range of motion explosive movement would be better but targeted performance (i.e., jumping capacity) will not come nearly as quickly.

Lower Extremity Plyometrics

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Plyometric exercises are most commonly utilized as a lower extremity workout to increase jumping performance.  A trainee that undertakes a lower extremity plyometric program will need to focus on proper form for each plyometric movement.  Form is pretty basic and intuitive, yet it requires attentiveness to agility, coordination and strength.  Since most trainees are new to plyometrics altogether, there is a lot of benefit that can be seen by paying special attention to the following aspects of jumping.

1. Knees over toes

If your knees are caving inwards on your landings then focus on consciously shoving your knees out as soon as you touch down.  This will help to avoid unnecessary stress on the knee joints.  Excess stress in awkward positions can and will result in overuse injuries.

2.  Throw your arms

The arms are a useful tool in generating forward and/or upward momentum on your jumps. Make sure you throw your arms out or up to gain the extra bit of height/distance on each jump.  Throwing the arms is a skill that takes time to hone.  The throwing of the arms should be synchronized properly with the jump, that is, the extension of the hip.  This takes time and practice.

3.  Soft landing surface

The landings of exercises that are labeled below with an asterisk are high impact and generally put a lot of stress on the knees.  This can lead to overuse injuries quite easily.  If possible, find something to ease your landings such as sand, soft dirt, or soft rubber matting.

4.  Fully extend

All jumps should go to full extension.  This means that your hips, knees and ankles should be extended (i.e. “straight.”)

Before we can address specific exercises is probably best to get some definitions of the terminology out of the way.

Nomenclature
Bilateral – Jumping with both legs.
Unilateral – Jumping with one leg.
Pistol – Jumping with one leg and going down into a complete range of motion.
Singles – Performing each rep with a pause between reps.
Series – Performing each rep in succession rapidly without any pause between reps.  This takes advantage of the stretch-shorten reflex to gain some height on each jump.
One Step – Jumping after rebounding off of a single step.  The momentum from the step loads the muscle with a quick, forceful stretch resulting in both a transfer of momentum and a more powerful stretch-shorten reflex.
Two Step – Jumping after rebounding off of two steps.   Provides more momentum than one step.
Running – Going into the jump with a run before hand.  Provides much more momentum than two steps.

NOTE: Before reading the list it is usually useful to look at some examples for reference.  Anything that is an essential or lesser known technique has been added to a short compilation produced by myself found below or here.

Exercises

  • Vertical Jumps – Jump straight up for height.
    • Singles or Series
    • Bilateral
    • Unilateral
    • Pistol
    • Running
      • One Step
        • Bilateral
        • Unilateral
      • Two Step
        • Bilateral
        • Unilateral
      • Full Run*
        • Bilateral
        • Unilateral
  • Broad Jumps* – Jump straight out for distance.
    • Singles or Series
    • Bilateral
    • Unilateral
      • Pistol
  • Box Jumps – Jump from the ground onto a box going for maximum height.
    • Bilateral
    • Unilateral
    • Pistol
    • Running
      • One Step
        • Bilateral
        • Unilateral
      • Two Step
        • Bilateral
        • Unilateral
      • Full Run*
        • Bilateral
        • Unilateral
  • Stair Jumps – Jump from the ground onto a stair/box going for maximum height and distance.
    • Bilateral
    • Unilateral
    • Pistol
    • Running
      • One Step
        • Bilateral
        • Unilateral
      • Two Step
        • Bilateral
        • Unilateral
      • Full Run*
        • Bilateral
        • Unilateral
  • Depth Jumps* – Start on a small object and jump down.  Rebound out of the landing with a jump of choice.
    • Vertical Depth Jumps
      • Bilateral
      • Unilateral
    • Broad Depth Jumps
      • Bilateral
      • Unilateral
    • Box Depth Jumps
      • Bilateral
        • Singles
        • Series
      • Unilateral
        • Singles
        • Series

* High Impact Exercises – avoid if you are unconditioned for plyometrics.

Upper Extremity Plyometrics

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Plyometric exercises can also be used to greatly enhance upper body explosiveness.  Both pulling and pushing movements can be greatly enhanced through plyometric upper body training.  In my opinion, training the upper body with a higher strength foundation through gymnastics techniques such as the planche, front lever, weighted pullups, weighted dips, etc. goes hand-in-hand with upper body plyometric training.  Strength training will build the foundation for the power that plyometrics aim to express.  Consequently, a combination of the two produces tremendous results.

Nomenclature
Hopping – Use the force of the push/pull to hop off the ground/bar.  The rebound back onto the ground or bar induces the stretch-shorten reflex to create more force for the next rep.
Clapping – After the hop perform a quick, audible clap.  The clap does nothing but ensure a higher, more forceful hop and acts as a useful metric.
Depth Drop – Similar to depth jumps, a depth drop starts your hands at a higher level and drops them down to a lower lever to induce a more forceful stretch-shorten reflex.
Drop Down [pushups] – A more extreme form of the depth drop.  Starting from standing, throw yourself at the ground forcefully to have more momentum behind the drop and thus a more powerful stretch-shorten reflex.
Burpees – Utilizing the drop down, the burpee allows for the goal of pushing back up explosively into the standing position with a forceful jump upwards.

Please note that, similar to jumping techniques, all techniques that make you go airborne require full extension. This means that your elbows should be straight and locked at the end of each rep.

NOTE: As stated above for the lower extremity, some examples for reference are likely to be useful to the new trainee.  Anything that is an essential or lesser known technique has been added to a short compilation produced by myself found below or here.

Exercises

  • Pushups – Start in a plank.  Lower the chest to the ground and back up to full extension.
    • Hopping
    • Clapping
    • Depth Drop
    • Drop Down
    • Burpees
  • Handstand Pushups – Start in a handstand against a wall or freestanding.  Lower the head to the ground and back up.  (Doing these elevated increases range-of-motion and difficulty.)
    • Hopping
    • Clapping
  • Dips – Start in a support position on bars.  Lower the chest to the hands and back up.
    • Hopping
    • Clapping
  • Kipping Pullups – Swing forward to stretch the muscles and pull back and up quickly utilizing stretch-shorten reflex.  Note that this move can take a bit of practice and requires some hip extension.
    • Standard
    • Hopping
    • Clap in front of chest
    • Clap on theighs
    • Clap behind the back

Programming

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Lower Extremity

Plyometric exercises for the lower extremity will be invaluable to any athlete looking to improve jumping performance.  In my experience, trainees will see a significant increase in jumping performance by implementing just a single plyometric exercise into their routine one or two times a week.  This should be no surprise given that the gains in a novice routine are mostly neurological and there is a the heavy neurological component of plyometric exercises.

Those trainees who get the most benefit are typically those who already have a very high level of strength.  Rather than require a 150% bodyweight squat, I would suggest a 150% bodyweight squat coupled with a 200% bodyweight deadlift.  Due to the explosive and plyometric nature of the power clean, it would be even better to have the ability to perform a 100% bodyweight power clean.  Do keep in mind that experience with these lifts, in my opinion, is not necessary but highly recommended.  If you have no experience with these lifts and want to enhance jumping performance then it may be a good time to start gaining some exposure to them.  You can most certainly work towards the strength goals (i.e. squat, deadlift, clean) I laid out above while also performing a high intensity plyometrics routine.  If you or your trainee, however, has a noticeably weak squat or deadlift and are particularly out of shape, then I would avoid most plyometrics until more basic goals are achieved.  Those that are not labeled “high impact” would likely be better candidates for these trainess but, please, use your head and best judgment.  For example, an obese 40 year old man likely has no business training box jumps and should probably focus on his weight loss goals and performing regular pushups before shifting focus to jumping performance.

As an aside, any of the programming tips below already assume that the trainee already has an existing strength program consisting of a warmup and strength work.  Generally speaking, plyometrics fall into programming order as laid out below:

A)    Warmup
B)    Skill Training
C)    Plyometrics
D)    Strength Work
E)     Metabolic Conditioning
F)     Stretching

Novice Programming
Simply put, the novice is anyone who has not attempted any plyometric training before.  This approach can also work very well for someone who has tried plyometrics but never trained for maximal gains.

  • Select 1-3 plyometric exercises per workout cycle (typically 4-6 week cycles work best.)
  • Vertical jump and broad jump are recommended as a great starting point for the novice.
  • Maximal effort of any plyometric exercise
    • For exercises that do not require progressive increases in equipment (such as vertical jumps or broad jumps) the trainee must simply jump as far as they can each rep.
    • Measuring each jump is useful to gauge progress even if it is just with some sort of landmark like a a basketball hoop or lines on the sidewalk.
    • Series jumps should be in sets of no more than 3 consecutive jumps.
    • Exercises that do require progressive increases in equipment (such as box jumps) should start moderately with something like an 18” box depending on the level of the trainee.
      • Increase the height of the box incrementally for every session that the plyometric training is performed.
      • Continue progress even if the increments are as small as ¼ inch every session.
    • Sets of 3 reps.
      • Trainees want to keep reps per set low since there is such a heavy neurological component.  Performing plyometrics while fatigued will be counterproductive and hamper progress.
    • Sets somewhere in the range of 3-7 sets.  If you are doing 3 reps per set then you will likely stick to 3 sets total.  If you are using a low amount of reps, such as single maximal attempts then you will likely use closer to 7 sets.
    • When going for maximal height on box jumps it is highly recommended that one use a spotter in the likely event of a failure that results in falling backwards.  Shin guards are also commonly used to protect the shins on maximal box jumps where a failure can cause the shins to scrape or smash on the box.

Intermediate Programming
The intermediate is anyone who has started to “fail” jumps at even the very smallest of increments to their max.  Even a lack of confidence in making jumps may warrant an intermediates’ approach to plyometrics training.

  • Select 1-3 plyometric exercises per workout cycle (typically 4-6 week cycles work best.)
  • Continued maximal effort in plyometric exercises that don’t require equipment
    • Exercises such as the vertical jump, broad jump and series jumps should be continued for maximal height or distance.
  • Begin submaximal intensity training n plyometric exercises that require equipment.
    • Exercises such as the box jump should be scaled down so that the target box on which you are jumping is not at a maximal height.  In example, scale a 30” maximal box jump down to 26” but perform 5 reps each set instead of 3.
      • This approach fosters an environment to better hone the skill of the movement rather than increasing an expression of force.

Upper Extremity

Plyometric and explosive training of the upperbody will certainly have high translation into slower strength movements.  Plyometric training for the upper body is much simpler than for the lower body.  Any of the movements can be done as a supplement or replacement for the bench press, overhead press, weighted pullup or weighted dip.  Simply replace any given weighted, slow workout with a more explosive version scaled down to a lighter weight or bodyweight.  Typically, for strength and explosiveness, one usually trains a plyometric or explosive upper body movement in tandem with a more strength-oriented similar movement.  For example, one trainee may work on clapping dips in tandem with weighted dips.  The former is for strength while the latter is for power.

Conclusion

To the top
While this guide is not totally comprehensive (nothing is), this should give a edge to any trainee looking to enhance jumping or explosive performance.  In as little as a single cycle with novice programming there is much improvement that can be made.  If there is any apprehension about adding these movements to your routine then I would highly recommend starting with a single movement with novice programming to get a feel for plyometrics.

References
1.  Ebben, W. P., McNeely, E., Haff, G.G.., Warpeha, J.M., Brumitt, J., Wein, D., and Riewald, S. T. (2007). NCSA’s Performance Training Journal: Plyometrics. Volume 6, Number 5. www.nsca-lift.org/perform

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5 Responses to “A Primer on Plyometrics”

  1. Wayne Riddle December 22, 2009 at 6:55 pm #

    Great article and some great exercises.

  2. James January 24, 2010 at 9:43 am #

    Thanks for posting this article. I’ve been incorporating a few plyometrics after my warm-up and I’ve been seeing faster gains in my Starting Strength lifts.

    For anyone who wants to try this, just be sure not to do too many lower body plyometrics before heavy squats. Sometimes it doesn’t work out too well…

  3. jump program November 12, 2010 at 12:33 am #

    You can also do weighted box jump. I am doing box jump as part of my exercise routine.Weighted box jump really works and really a power workout. Doing plyometrics for 1 to 2 days can lead to significant increase in muscular strength and power.

  4. Bomb Jack December 8, 2011 at 10:19 am #

    Hi,
    do you recommend the same reps/sets/#exercises pattern for the upper body?

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  1. plyometrics workout equipment - July 10, 2013

    […] A Primer on Plyometrics | Chris Salvato http://www.eatmoveimprove.com/By the end of this article, you should be very familiar with the concepts of plyometric training and how they can be applied to a variety of movements in a comprehensive training program. Before reading further, do understand that some of the recommendations I make … It is quite common that most trainees cannot or will not train weighted squats due to lack of proper instruction or equipment. I would suggest that if one has little or no experience with the squat and/or … […]