BY PETROS SYRAKOPOULOS
Jumping ability is a major component of athleticism. In sports like basketball and volleyball, where how high you can reach will determine how effective you are on the court, being able to jump higher can make a huge difference in an athlete’s performance. Increasing your vertical jump is indeed very challenging and, in order to be achieved, requires a lot of hard work of the right kind. Taking the steps necessary to accomplish this can have a substantial impact on your career as a professional athlete.
The first step to take is to understand the factors that determine how high you can jump, and how they can be manipulated. This is what this article is about.
A Story about Physiology
It is well known that genetics play a substantial role in jumping ability. Take any group of teenagers with similar training histories (lets say, kids who have never done any type of structured training, or kids who have been playing basketball the same number of years on the same team), test their vertical jump and you will find large disparities between individuals. This happens because the physiological and biomechanical factors that affect jumping ability are genetically determined to a significant degree.
So what are the factors that determine how high you can jump?
First off, there are certain architectural factors (limb length ratios, muscle insertion points and tendon lengths) which are 100% genetically pre-determined and cannot be affected by training. An athlete with shorter calf muscle bellies and longer tendons will be able to store a greater amount of elastic energy during a jump with a run up, which can contribute to a higher jump. Secondly, there are some physiological factors, like fast-twitch muscle fiber percentage and connective tissue quality, which are genetically determined to a great degree. These factors are hard to improve, and well-designed and properly-executed long term training is required in order to develop them. Finally, there are certain physiological factors, like relative strength and percentage of body fat, that are easier to influence. These can be affected by proper interventions, and substantial improvements can be achieved over relatively short periods of time. But don't fool yourself: even these attributes that are more amenable to change require a great amount of effort.
While realistic expectations are important (since some of the factors that affect jumping ability are genetically determined, everybody’s “genetic ceiling” of how high they can jump is different), the take-home message here is that every athlete can improve their vertical jump. No matter if you are a naturally talented jumper or if the vertical jump has always been a deficit for you, unless you’ve been doing properly-designed athletic development training for a number of years, it is certain you have yet to reach your genetic ceiling and have room for improvement.
If that is so, then what should this “properly-designed athletic development training” look like?
The two main attributes which affect jumping ability, that should be targeted during athletic development training, are your explosive strength and your elasticity. Lets have a look at each one of them.
Explosive Strength
Explosive strength is the amount of force an athlete can produce in short timeframes. For instance, in the standing vertical jump, the time of force application is around 250 ms. The greater force the athlete can produce in those 250 ms, the higher his jump is going to be.
In order to increase your explosive strength, you need to increase your max strength (the force you can produce irrespective of time limitations) and your rate of force development (how fast you can produce force). Greater max strength means being able to produce a greater maximum amount of force in the specific movement, whereas higher rate of force development means a greater percentage of your max strength is produced within those 250 ms of force application time in the standing vertical.
Max strength is developed by performing the main movement with heavy weight (typically 80% or more of your 1 rep max). This can include different types of squats, step-ups, lunges, etc., but the important element for training to be successful is going heavy. Max strength can be improved relatively fast (athletes can often achieve impressive improvements within the span of just a few months), but, due to the fact that heavy loading is necessary, it requires perfect technique (in order to avoid injury) and a great amount of mental effort from the part of the athlete. For more info on max strength training and how it affects explosive strength, take a look at this article.
Rate of force development is increased by performing the main movement with lighter weight (typically 30-70% of your 1 rep max) in an explosive manner. This can include explosive exercises such as olympic lift variations, jump squats, band-resisted work, different types of unloaded or lightly loaded jumps, etc. This type of training also requires proper execution and proper programming.
Keep in mind that, when it comes to jumping, which involves accelerating your own bodyweight, what really matters is your “relative strength” (i.e. your strength relative to your bodyweight). For example, a 140 kg squat may be a good level of max strength for an athlete who weighs 70 kg, for whom 140 kg is twice his bodyweight, but it is quite low for an athlete who weighs 120 kg, for whom that is only 1.17 times his bodyweight. This means that proper programing, as well as a proper diet, are important for achieving and maintaining an optimal amount of muscle mass as well as a low percentage of body fat.
Elasticity
Elasticity is a very important physiological property affecting jumping ability. Elasticity in physics is defined as the ability of a body to resist a distorting influence and return to its original shape when the stress is removed. Simply put, elasticity is what happens when you stretch an elastic band and then release one end: energy is stored into the band (in the form of elastic deformation) and, when released, is converted into kinetic energy (into motion).
A similar thing happens when bending down before you jump: as you bend down, kinetic energy from the downward motion of your body mass is stored in your connective tissues (in your achilles tendon, for example) in the form of elastic deformation (your achilles tendon elongates), and then is released back as kinetic energy to aid you in your jump. This is called the “stretch-shortening cycle”: as you bend down, your muscle-tendon unit stretches (storing elastic energy), then, as you switch direction from downwards to upwards, it shortens again (releasing the stored energy). This is why tendon length (which is a genetically pre-determined attribute), and connective tissue quality (tendon thickness, collagen quality, etc.) can affect jumping ability: a longer, thicker achilles tendon will be able to store and, subsequently, release a greater amount of elastic energy.
For the same reason, the faster you dive into the “stretch phase”, the greater the energy you can store in your connective tissues. This is why you can jump higher with a run-up as opposed to jumping from a half squat. Moreover, the harder you can contract your muscles during the stretch phase, the greater the energy you can store in your connective tissue. If your muscles can’t contract as hard, a greater amount of the downward kinetic energy is going to be lost: a relaxed muscle makes for a much less stiff, less elastic, muscle-tendon unit. This ability to explosively contract your muscles in the stretch phase of a jump is called “stiffness”.
Here is a simple way to understand what elasticity is: assume a half-squat position, pause for 3 seconds, then jump straight up without any countermovement (we call this a “squat jump” and it doesn’t incorporate the stretch-shortening cycle). Now stand, squat down to a half-squat and jump back up (we call this a “countermovement jump” and it incorporates the stretch-shortening cycle). Now take a run-up, step with both feet and jump (the jump with a run-up makes even greater utilization of the stretch-shortening cycle). You will notice a substantial difference between attempts: you can jump higher with a countermovement, and even higher with a run-up. This difference between a squat jump and a jump with a run-up is the incorporation of elasticity. If you were to test different people, you would notice that some of them have a greater discrepancy between their squat jump and their jump with a run-up. The greater the difference between the two, the “more elastic you are than you are strong”. Similarly, the smaller the difference the “stronger you are than you are elastic”.
Elasticity development is a long-term process, because stiffness and connective tissue quality take a long time to improve. The means to develop these attributes is plyometric training. This can include hurdle work, bounds, various types of repetitive jumps, depth jumps and sport-specific drills on the court. In order for plyometric training to be effective, it needs to be high-impact. Stresses on the joints during this work can be very high, therefore exercises must be performed with good movement and must be properly programmed.
Are things getting a bit complicated? Let’s see what all this means for your training!
Putting it all together
We’ve seen so far that jumping ability depends on two distinct qualities: explosive strength and elasticity. Elasticity is the amount of energy than can be successfully stored during the “stretch phase” and released during the “shortening phase” of a jump, whereas explosive strength is the amount of force that can be produced by muscle contraction during the shortening phase.
Explosive strength depends on relative max strength and rate of force development. Relative max strength is the attribute that can be improved the fastest, but requires the most arduous, most grueling kind of work: lifting heavy and getting your diet in order. Rate of force development involves explosive efforts across a range of lighter loads ranging from unweighed jumps to near-maximal power cleans.
Elasticity depends on architectural factors outside your control, but also on stiffness and connective tissue quality, which are two things that are slow to change but can be developed with the proper kind of training. Properly designed plyometric training is the type of work required.
Where should you focus?
Are you “more elastic than you are strong”? This happens to many kids who have been playing sports for many years but haven’t engaged in serious, properly-designed, strength training. They have worked on their elasticity for many years through sport-specific training, but are weaker in comparison. They will receive great benefit from working in the gym to increase their max strength and rate of force development.
Are you “stronger than you are elastic”? This often happens to people who have an unfavorable genetic pre-disposition towards elasticity. It can also happen to people who have spent more time lifting in the gym, than doing sport-specific training. They will benefit from focusing more on explosive and plyometric work.
Are you a beginner in sports or at a lower level on both attributes? You should focus on building a strength base (which, in this case, is the low-handing fruit since it is faster to accomplish and is also important for injury prevention), while working on improving your movement mechanics. Once your max strength is starting to improve, you can gradually incorporate rate of force development work, and, eventually, plyometric work.
These are some simple guidelines for where an athlete should direct their training focus. Having said that, it is important to understand that during the long-term evolution of an athlete, their athletic attributes will change and their training has got to adapt to their changing needs. Furthermore, good movement mechanics and resolution of musculoskeletal imbalances are necessary in order for performance training to be effective. In all three scenarios, working with a competent athletic-development professional who can provide proper programming and good coaching is highly recommended in order to work towards your goals safely and efficiently.
Petros Syrakopoulos is a member of the Performance 22 coaching team since 2012 and is currently the strength and conditioning coach of greek major league team Arcadikos BC. He graduated from the School of Physical Education and Sport Science of the University of Athens in 2013 with the highest grade in the school’s 30-year history.
