Plyometrics are similar to the dynamic moves that kids do like hopping, skipping and jumping around. They are exercises designed to increase speed, power, and explosiveness.
The more explosive you are, the better you will perform on your big lifts.
In this article, I’m going to explain the science behind plyometrics, how you can implement it to your training to develop explosive power and why simple jumps don’t work.
Intro – What Are Plyometrics?
Unlike typical strength training exercises that involve slow movements, plyometric exercises are quick, explosive movements designed to increase speed and power.
Plyometric exercises consist of three phases.
The first is the eccentric phase, a rapid muscle lengthening movement. Let’s think of it as the landing.
The second is the amortization phase. This is like an extremely short rest period.
Then there is the concentric phase, a muscle shortening movement a.k.a. exploding off the floor.
How quickly you leave the floor is dependent on your ability to store and release elastic energy.
You must do this cycle as fast as you can. The goal should be to decrease the amount of time between landing and exploding off. This is how you should do plyometrics to become faster and more powerful.
Brief History of Plyometrics
Plyometric training to improve sports performance was developed by Russian exercise scientist, Yuri Verkhoshansky, who specialized in the jumping events in track and field.
His first article about this training method was published in 1964 and his pioneering work eventually earned him the title of “Father of Plyometrics”.
Back in the day, Verkhoshansky was looking for new methods to take the jumping ability of his athletes to the next level and reasoned that since there seemed to be a correlation between short ground contact times and better performances in triple jumpers, this could imply that a greater stiffness could be the key to improved jumping ability.
Soon his athletes started doing depth jumps focusing on reducing ground contact times, switching from eccentric to concentric action more quickly.
Then he developed a system of exercises to increase the speed and explosiveness of Russian track and field athletes.
This power-boosting routines consisted of repetitive jumps, not only straight up but also in different directions, and included footwork (speed drills), stretching and weight training.
The term “plyometrics” has roots from the Greek word “pleythyein”, which means to increase or augment and from the latin word “metrics” which means to measure.
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| Yuri Verkhoshansky (left) with a Russian track & field coach and a t&f bronze medalist. |
Although Verkhoshansky was deemed the “father of plyometrics”, he didn’t refer to it as such. He called it the ‘shock method’.
The term “plyometrics” was coined by American track and field coach Fred Wilt, who after watching the Soviets dominate the Olympics and other athletic competitions during the 60-70’s, decided to investigate how they were training.
He did, and what he saw was a bunch of guys jumping and skipping around like children.
After ‘spying’ on their methods, he started taking notes as he was convinced those happy jumps Soviet athletes were doing in preparation for their events were key to their success.
Back in America, he decided to implement this method with his athletes and came up with the term “plyometrics”.
In the process, he learned that Dr. Michael Yessis (who visited and worked with Verkhoshansky himself later in the early 80’s) was also doing work on the Russian training methods at the time and quickly started collaborating with him to spread information on plyometrics.
Since then, athletes around the world have used plyometrics to become faster and more explosive.
What makes this even more interesting is that these events took place during the Cold War era when sports rivalry was a serious thing.
How Plyometrics Work
Like I said before, typical strength training exercises consist of relatively slow movements of longer duration designed to increase muscular strength and mass while plyometric training consists of quick, explosive movements designed to increase speed and power.
Thus plyometrics are all about empowering the nervous system.
During muscle contraction, the brain communicates with the muscles through the neuromuscular system. The faster this communication happens, the faster your muscles will contract and the faster you will move.
But plyometrics work inside the muscle as well. Your muscles have different types of muscle fibers, there are slow twitch and fast twitch fibers. We all have both, some people are fast twitch dominant while others are slow twitch dominant and some muscles naturally favor one type over the other by default. Your muscles’ fast-to-slow twitch balance can be altered by the nature of the activities you engage as far as human nature and your individual genetics allow.
The slow type are dominant in endurance athletes like long distance runners while sprinters are full of fast twitch fibers.
Plyometrics not only strengthen fast twitch muscle fibers but actually increase their quantities inside the muscles.
Going back to how plyometrics work: making the stretch-shortening cycle happen as quickly as possible is the basis of all plyometric exercises.
The stretch shortening cycle consists of the three phases we spoke earlier:
- When you jump, the landing creates an eccentric load and your muscles and tendons get a fast stretch.
- The second is the amortization phase, this is the time it takes you to land and takeoff again.
- Then comes the concentric phase where the stretch created by the impact of ground contact will power up your jump, making your muscles contract with more speed and force than a dead-start concentric action alone would do.
These three phases are repeated as quickly as possible to develop power. How quickly you switch from eccentric to concentric contraction determines the effectiveness of the exercise.
True Plyometrics – Not All Jump Exercises Are ‘Plyometric’
Therefore, a box jump is a power exercise, but not a plyometric exercise. Because there is no eccentric loading a.k.a. no bounce.
Power = Strength x Speed
To be ‘plyometric’, an exercise has to make use of the stretch-shortening cycle and for this ground contact has to be extremely short (0.1 – 0.2 secs).
That’s the original version of plyometrics by Verkhoshansky.
Not all jumps are plyometric and not all plyometrics are jumps.
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| Dr. Verkhoshansky at the lab. |
These days any jump is called plyometric regardless of execution time.
For the upper body, it’s now common to refer to ballistic exercises like medicine ball throws as plyometric exercises and some sports science coaches regard them as essential for converting strength into power.
And they can be effective, it’s hard to argue with the results that many athletes are getting from this type of ballistic work especially in combat sports, but they’re not true plyometrics.
If we take Verkhoshansky’s word that plyometrics improved jumping performance by increasing stiffness, then these type of ballistic exercises shouldn’t be regarded as truly plyometric, therefore, effectiveness of plyometrics shouldn’t be judged by the results of such training methods.
Beyond definitions, the best way to go is using both the original plyometrics and ballistic exercises, the modern ‘plyometrics’.
Methods for Explosiveness – Shock Method via Depth Jumps
It’s called the “shock method” because it is an impact that the body has to absorb followed by a rapid change of direction – when landing from a depth jump, your hips, knees, ankles and leg muscles experience a shock that forces an eccentric contraction (lengthening) which then propels the athlete to jump (shortening) as high as possible.
The neuromuscular system must be lightning fast to coordinate these actions.
It’s important to know that most of the stretch-shortening thing happens in the tendons that attach to the muscles involved rather than in the muscles.
The Depth Jump is performed by standing on a raised platform abut 20-30 inch / 50 cm high, then the athlete drops down, lands, absorbs the shock and instantly explodes (the landing period should take no more than 0.2 seconds). The bigger the drop, the higher it should enable you to jump afterwards.
It’s like going to a festival, the build up would be the eccentric loading and then when the drop comes people jump. They don’t wait a single second, that would be wasting energy. Pogo jumps all night.
Of course, beginners aren’t conditioned for depth jumps.
Starting height should be quite low in the early stages so your joints can adapt progressively to the impact, about 12 inches for starters.
Platform height should only be increased when your jump plateaus and you can’t make any more progress, never going above 45 inches. Elite athletes may drop from 50 inches, but in reality, above 40-45 inches it starts to get counterproductive and will surely end in injury because your muscles can’t take such force.
Execution: As you takeoff, you should prepare for impact by tensing the muscles. Remember, stiffness.
The landing surface should be easy on the joints. Slightly flex the knees as you land to better distribute and absorb force.
If you can’t stop going downward, maybe the takeoff platform is set too high for your capacity or you’re not contracting your muscles hard enough.
The strong eccentric contraction prepares the muscles to switch to the concentric contraction in an explosive manner for takeoff.
The Depth Jump is the king of plyometrics for developing reactive ability.
Jumping technique is very important, two athletes can produce the same power output but jumping height will be lower for the athlete with less technique. (Don’t try plyometrics if you can’t even jump properly, groove that pattern first).
Jump as high as possible every time and keep in mind the shock method is very taxing on the central nervous system (CNS), don’t overdo it. Do depth jumps no more than 2 times a week and never do them for high volume, 10 total reps per session should be enough for starters.
The effects of depth jumps are not only short term, they lead to greater strength gains and explosiveness in the long term.
When doing depth jumps, is mandatory that you leave the floor immediately, the longer you stay the less elastic boost your jump will have and the plyometric value will be lost. Ground contact time for elite sprinters is 0.08 seconds…
“If the transition phase is prolonged by more than about 0.15 seconds, the action may be considered ordinary jumping and not classical plyometrics.”
Here is a video of Dwayne Wade doing Depth Jumps:
Methods for Explosiveness – Regular Jumps
This is the reason why most exercises you see labeled as plyometrics are not actually so – because the switch between eccentric and concentric contraction is too long to induce the stretch reflex, causing the loss of all elastic energy.
There is nothing wrong with simple jumping exercises, though.
These jumps executed without focus on execution time train jump strength, acceleration and force absorption and are also effective for those who engage in activities that don’t require explosive movements.
A long distance runner would benefit from high rep jumping (20-30) and generally longer circuits (although they can benefit from doing plyometrics too).
These jumps are also useful as a warm-up / preparation for plyometrics, especially for beginners.
But they are not plyometrics.
You should be aware if the type of jump you’re doing develops jump-strength or power and explosiveness; if ground contact isn’t extremely minimal, it’s not a true plyometric.
It’s All About The Bounce
The approach is simple, think of a ball: when you throw a ball against a hard surface, it just bounces back.
If you’re not bouncing like a ball, you’re not using the stretch reflex and elastic energy.
Every rep should be bouncy. Think quality, not quantity.
This applies to all athletic skills and movements, if you move wrong when training you will program the wrong motor patterns into your nervous system.
With these principles, now you know how to distinguish between a simple jump and a true plyometric movement and that you’re doing it right if you feel bouncy.
The Studies On Plyometrics For Improving Power Output
The Science of Performance EnhancementSome of the studies cited at the end of this article analyzed the effects of plyometric training on muscular power output during long term trials.
Some of the studies used plyometric training alone while others combined it with other training methods such as weightlifting.
The studies were done on both experienced and untrained males and females of different ages ranging from children and teenagers to college and professional athletes.
The majority of the results favored plyometric training as a power enhancing tool. Athletes experienced results like improved muscular power output, jumping ability and squat strength.
Some of the studies even showed improvements in muscle mass and muscle fiber size as a result of plyometric training. Suggesting plyometrics not only work on a neuromuscular level but can also make adaptations inside the muscles.
A few studies didn’t find any significant improvements on power output by doing plyometric training.
In summary, plyometrics are a legit tool for improving power and explosiveness according to science. It is not a miracle method, but I believe it’s essential for performance enhancement.
Still the literature on the subject is very limited and more research is needed to learn more about the effects of plyometrics and how to implement them more effectively.
General Tips & Considerations
- Other than depth jumps, there isn’t a clear superiority between plyometric exercises in terms of effectiveness.
- What is more clear is that higher frequency plyometric training usually leads to faster gains in muscular power output.
- Pogo jumps are a good plyometric exercise for starters.
- For experienced athletes who don’t want to stimulate hypertrophy, plyometrics are not a problem.
- Jump exercises and low-mid intensity plyometrics prime the nervous system, that’s why track coaches begin their practices with jumps and bounds. Jump exercises prime the nervous system for subsequent activity such as speed drills. For us lifters, starting workouts with jumps and plyometrics before weightlifting will get the central nervous system primed so your muscles can fire at optimal levels, helping you get more out of the rest of the workout. However, Depth jumps (the king of plyometrics, and the most advanced one) are so taxing that they should be done at end of the workout or as a separate session.
Injury Risk
The ‘Please Stay Safe’ ConsiderationsPlyometrics put a lot of stress on your joints and tendons.
You can start doing plyometrics without a strength base, but your gains will not be optimal and you will get injured.
The proper strength and hypertrophy levels must be developed to support the stretch and the increased power output it produces.
Experts advice that you can squat at least 1.5 times your bodyweight before attempting depth jumps.But you won’t be ready for intense plyometrics by just lifting weights.
If you never do cardio, go do some (conditioning joints for impact). Do single leg exercises for balance and stability. If you always do heavy squats and deadlifts, start doing quickness drills (conditioning for explosive movements). Do static stretching in your free time and dynamic stretching before training if you aren’t already (flexibility). Then start with general jump training and progress to advanced plyos.
All of this will prepare your tendons for plyometrics much better than weight lifting alone.
Rest enough between plyometric sessions (1-2 days) and always avoid jumping on hard surfaces.
Some of the studies (cited at the end of this article) showed that if done correctly, plyometrics can actually reduce the chance of lower body injuries.
Recap – Benefits of Plyometrics
I don’t like abusing the word ‘functional’, but plyometrics are just that. They improve the functions of the muscles, tendons and nerves which will boost your performance in sports and life.
- Increase fast twitch muscle fibers – This empowers your muscles by allowing them to produce faster contractions, which leads to increases in power output.
- Stronger Tendons – This means fewer injuries. A study had a group of male runners doing plyometrics for 6 weeks which resulted in improved running economy over 3 kilometers due to strengthening of the musculotendinous system. That means their bodies became more efficient in receiving, distributing and producing force while expending less energy and staying fresh. This makes plyometrics useful for endurance athletes.
- Stimulate Neuromuscular System Efficiency – Plyometric training improves the efficiency of the neuromuscular system. During athletic performance, your brain sends signals to your muscles to contract, the more efficiently your nervous system can transmit this signal, the faster your muscles will contract, increasing your speed and power. Plyometrics offer improved explosive and reactive ability and a sharp CNS (central nervous system), which means performing better and with more ease.
- Stronger lifts – Olympic weightlifting requires a huge amount of power from your muscles. Plyometrics can teach your body to fire quickly, which decreases the time it takes you to reach maximum force thus improving your power output. Studies have found that a combo of squats and plyos greatly increased hip and thigh power production.
- Enhanced General Performance – It doesn’t matter if your main activity isn’t lifting weights, plyometrics can help you run faster, jump higher, and hit harder. Actually, they work even better for those type of athletes.
- Almost No Equipment Needed – You can use objects that are lying around your house to do your plyometric routine.
- For All Needs – Plyometrics can be adapted to any athlete’s needs and physical capacity.
I’m a firm believer that explosive training keeps you ‘young’ as you age.
Final Word
If you’re reading this blog chances are you’re a lifter or strength athlete and not a track and field athlete.Many coaches claim that just because something doesn’t mimic the exact specific skills of a sport, it has no value.
For example, there are many coaches in olympic weightlifting that don’t even believe in any exercise variation other than the full classic lifts and squats.
They say partial pulls and lifts from blocks are useless for their lifters because technique isn’t the same, yet lifters from other teams who do them keep outperforming their athletes.
If you don’t compete and train on your own, like me, then you have no reason not to do something if you believe it can improve your performance just because X coach says it doesn’t.
You will obviously adapt the exercises to better fit your goals i.e. if you want to squat more, focus on vertical plyometrics. But even then don’t be afraid to step out of your comfort patterns every once in a while.
You have the evidence here, plyometrics will make you faster, more powerful, explosive and functional.
Try them, and if you come across any article or video spreading misconceptions on plyometrics, link them to this article.
Stay tuned for the next article on this series with 10 of the best plyometric exercises you can add to your routine.
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