Plyometrics is a type of training that uses the stretch-shortening cycle to produce maximum force in a minimal amount of time.
Not only it trains the muscle in a specific way, but it also targets the central nervous system.
In the Strength & Conditioning world, plyometrics is the closing gap between training for maximum strength and training for explosive power.
It makes you a better athlete by stimulating:
- The central nervous system
- The rate of force development
- Explosive power
What is plyometrics?
It is now defined as jumping exercises that involve an eccentric contraction, immediately followed by a short isometric contraction, and then by explosive concentric action.
What are plyometric exercises good for?
If you are an athlete, for basically everything.
Using plyos during your training will have a significant effect on:
- Vertical jump
- Max Strength
- Change of direction
- Explosive power
All of these factors are essential for every single athlete, whether you play a team sport or not, or if you are a combat sports athlete.
Not only, but plyometrics will also make your connective tissues and bones stronger and more resilient, less prone to injuries.
It is also essential in any sport that requires a higher degree of acceleration than max speed, which is what happens in the majority of sports.
What athletes generally need the most is the ability to accelerate and decelerate rapidly, a factor much more important than actual max speed.
Plyometrics is a great way to train this component, and it shows to be extremely useful for training the 10 to 40yard distances, making it great for basically any sport.
Paying more attention to max speed is a mistake made by inexperienced Strength Coaches worldwide.
Short distances ran at maximum acceleration is where the focus should be.
The three phases of plyos
Plyometrics involves three phases:
- Eccentric (loading)
- Amortization (transition)
- Concentric (unloading)
During the eccentric contraction, we load the muscles by lengthening them.
In this phase, we accumulate elastic energy in our muscles and our connective tissues.
The transition phase is the isometric contraction that happens between phase one and phase three, and it should be as quick as possible.
A long transition phase will not produce a fast concentric phase, limiting the force output of the athlete.
A short transition phase will maximize the utilization of the stretch-shortening cycle.
During the concentric and final phase, we finally use the elastic energy that we have accumulated in phase one, and we release it in a max effort manner.
With plyometrics, we recruit the biggest and most performing motor units, using the elastic properties of muscles and connective tissues.
Plyometrics and injury prevention
Even though it’s not the main reason why we use it, plyometrics also works great for injury prevention.
Some of its benefits are:
- Better motor control of the lower legs and core during landing
- Increased knee stability
Both of these factors become very helpful in professional athletes.
How does plyometric work?
Thanks for the direct training of the stretch-reflex.
Try this to see it in action for yourself.
Stand in a neutral position, then flex your knees and squat down.
Stop there for a second or two, then jump, but make sure you film yourself.
Now do the same thing, but this time squat down quicker, don’t pause there, and immediately jump as high as you can.
I’m pretty sure that the second jump was much higher than the first one.
That happens because, in the second version of the jump, you used the elastic energic.
The same thing also happens during a barbell back squat, which is always higher than a box squat because, in the regular version of the squat, you do rely on the elastic energy, while in the box squat, you let it dissipate on the box.
The box squat is generally at least 10 to 15% lower than a back squat for this exact reason.
The same thing also happens during a pause squat, which, again, is always lower than a normal back squat.
The six mechanisms of plyometrics
There are six main reasons why Plyos will make you a better athlete:
- Increased muscle spindle activity: the faster the eccentric, the higher the concentric force we can apply. Related to the central nervous system.
- Desensitization of the Golgi tendon organ: it promotes the muscle force we can produce by inhibiting the GTO.
- Enhanced neuromuscular efficiency: motor control and motor unit recruitment is increased, which translates to better performance.
- Increased max strength: in most weaker athletes, plyos will make you stronger, especially when using the shock method (drop jumps or depth jumps). Unfortunately, in stronger athletes, the max strength won’t be increased as much. You will need to squat and deadlift.
- Enhanced muscle activation: by utilizing the stretch-shortening cycle and recruiting more motor units, we also active a more significant number of muscle fibers.
- Enhanced muscle coordination: intra-muscular coordination increases with plyos, which will make your movement more efficient and will allow you to use all the explosive power you have, with the correct timing and motor control.
Training volume for plyometric exercises
In resistance training, the total work volume is calculated through the number of sets, weights, reps.
As far as plyos, we count the number of contacts to the ground.
Training has to be individualized, but we can give some general guidelines for volume, like:
- Novice: 80-100
- Intermediate: 100-120
- Advanced: 120-140
Volume not only changes for the single session and level of the athlete but also with the intensity of the chosen exercise.
As the intensity increases, the volume drops, and vice-versa. We, as Strength Coaches, have to be very careful in programming plyometrics to prevent possible injuries or at least reduce its risks.
There are a vast number o jumping exercises we can use to make an athlete better at running, jumping, change direction, etc. In novices, for example, we can use:
- Squat Jump
- Split Squat Jump
- Box Jumps
During the Nasm – Performance Enhancement Specialization Course, I was taught that initially, you should stabilize your body for at least three to five seconds after every jump.
I’ve found this to be very dull, but extremely helpful for those athletes who still don’t move correctly and aren’t capable of absorbing forces.
As far as intermediate athletes, we can add a few more exciting jumping exercises such as:
- Tuck Jumps
- Butt Kicks
- Power Step Ups
All of these exercises can be used in different ways, with maximal intent to produce higher power outputs.
For the advanced athletes, we can use the same exercises once again, but increasing the intensity: for example, we can wear weight vests or use dumbbells or kettlebells.
Or, even better, we can start using the depth jump, the real “shock method” created by professor Verkhoshansky.
With the depth jump, for which you should be well prepared (high eccentric strength in the squat), the forces that you put your body through are incredibly high.
But, it’s also the best type of plyometric exercise you can do: so make sure to include it if you are a strong athlete and ready for it.
The depth jump can be used from lowe boxes, such as 20 o 24 inches, all the way up to 40 inches or even more, but only for very strong and well-prepared athletes with years of experience in jumping and weight training.
As you can see, plyometrics is a vast training modality, but it has a few limits, unfortunately.
Prerequisites for plyometrics
Plyometrics is an advanced form of training, born as the “shock method” by Verkhoshansky (Supertraining).
It requires the athlete to have a decent amount of:
- Core stability
- Motor control
- Max eccentric strength
Many authors suggest using plyometrics only when you can perform at least twice your weight for a one-rep max in the squat. Others think 1,5 times is enough.
You should be very strong, not just for injury prevention.
The stronger you are, the more effective plyometrics will be in making you a better athlete.
An athlete that weighs 100 lbs and has a 140lbs back squat will not improve much by training with plyometric exercises, unfortunately.
Strength is the mother of all qualities. (Bompa)
Being extremely stressful for the central nervous system, many authors suggest doing plyometrics only once or twice per week; some bring that up to three sessions a week.
Many would agree on doing high-intensity plyometrics only once or twice per week, or every 40 to 72 hours, while lower intensities plyos can be used more often.
When should plyometric training be used?
It can be used year-round, with an emphasis on the weeks preceding the season and in-season.
Far from the competition, most athletes will benefit more from general physical preparation, strength training and speed training.
The closer you get to the competition or starting season, the more relevant plyometric training becomes.
Is plyometrics aerobic or anaerobic?
If you do it correctly, it’s mainly anaerobic.
We use plyometric training for explosive power, speed, acceleration, and stability, not as a form of aerobic training.
Plyometric exercises are one of the best tools in our arsenal as Strength Coaches and athletes.
If you want to improve your stability, acceleration, explosive power, change of direction, agility, and even max strength, you can’t omit plyometrics.
With plyometric exercises, you can increase the vertical jump and reduce the risk of many types of injuries since your tendon stiffness will dramatically improve, and you will also gain enhanced overall joint stability.
Unfortunately, athletes will need to be strong enough to jump into (pun intended) high-intensity plyometrics.
Until then, they can start with lower intensity exercises such as box jumps, trap bar jumps, band resisted barbell squat jumps and more.
Make sure to improve your overall and eccentric strength in the meantime since plyos can be one of your best allies.