Taking a Look At The 2 Different Types of Leapers
There are 2 dominant types of leapers with most people possessing a tendency towards one or the other. The first type I'll cover is the strength jumper
The strength jumper tends to rely more pure strength and explosive ability to get up in the air. He tends to look a little less "springy" and a lot more “powerful” when he jumps. He may even appear and sound like he’s tearing holes through the floor when he takes off! When choosing his jumping style, he'll definitely tend to do best jumping off 2 feet and likely feel quite horrid jumping off of 1. He'll also tend to use a deeper knee bend and may also have physical characteristics like thicker muscles and joints. He will tend to have natural levels of "strength" that are greater then his natural levels of "bounce", or reactive ability.
At the extreme end of this group are athletes like olympic lifters and throwers. Many of these guys have spectacular vertical jumps along with spectacular rate of force development. They can exhibit their impressive power from a virtual standstill, but you won't see them dunking from the free throw line or winning any high jump medals.
Now realize that not all strength jumpers are strong or can jump, it's just that their body structure, muscle-tendon lengths etc. will naturally tend to make this their dominant style when they do begin working specifically for vertical jump improvement. Some people are "strength" jumpers but don't know it yet because they may not yet have any strength. Having said that, as long as this style of jumper has his strength levels up to par, he'll make further gains using plyometric and accelerative methods which, when coupled with his strength, will make him even more explosive and smoothen out his rough style. At the upper levels of sports, natural "strength" jumpers also learn to become smooth and graceful as well. Think for a minute about some of your favorite dunkers and I'm sure
you can identify a few that fall into this group.
The 2nd type of leaper is the elastic jumper.
The elastic jumper, also known as the reactive, elastic, or plyometric jumper, tends to naturally be more fluid and often appears to take off effortlessly into the air when he jumps. He just looks bouncy. Most of the time, he will be gifted in the structural department with long legs, long achilles tendons, and small joints. He also tends to naturally be able to get up higher jumping off of one leg with a running start then he will be with a short 2-legged take-off or from a standstill. His levels of strength may often seem inconsistent with his performance and he probably won't be turning many heads in the weight room. The elite level high-jumper or long jumper are both excellent illustrations of extreme elastic jumpers.
The reasons the elastic jumpers tend to excel at this style of jump are due mainly to
structure (length of the bones, muscles, tendons etc.), but also muscle fiber considerations. They naturally tend to rely more on the action of the stretch-reflex and involuntary plyometric ability. In contrast to the strength jumpers, over time at the upper levels, elastic jumpers learn and train to become more like strength jumpers. They do this by increasing their pure strength and voluntary rate of force development. Since the elastic jumper is naturally bouncy and gifted in the plyometric department, it usually doesn't require as much focus in his training. Michael Jordan is a good example of an athlete who was naturally an elastic jumper but who also learned to become an excellent "strength" jumper.
In addition, most will favor a bilateral 2-legged takeoff if they rely more on their strength because one can obviously apply more muscular force with 2 legs than with one.
Those who favor a 1-legged take-off do so either because their natural structure and build favors the quick reflexive rubber band type action in the tendons rather then pure voluntary explosive strength,- or because they don't have enough strength or aren't yet able to apply their strength quickly enough (rate of force development) to execute a powerful 2-legged take-off. This is why some people with sub-par jumping ability will gravitate towards this style.
Different Means - Same Result
To explore this a little deeper, jumping is inherently plyometric and regardless of your style of jump (1-leg or 2), there is still a process of stretching, stabilization, and reaction
in the tendons and musculature of the lower body as you plant to take off. No matter what your dominant qualities are, you can both improve and learn to use your plyometric
ability optimally, but there are differences in how you might go about doing it and the qualities required.
The plyometric/reflexive/reactive/ or elastic contribution to jumping can be divided into two categories, long and short response reactivity. Recall from the plyometrics chapter, as you plant to jump, the brief time you spend changing direction as you're on the ground just before the take-off is called the amortization phase.
When executing a jump with a 2-legged takeoff the amortization phase is around .250 seconds or greater which, when it comes to plyometrics, can be considered long. We can call this longer response reactive ability because the ground contact times are fairly long.
When leaping off of one foot the amortization phase is shorter than .250 seconds and generally closer to .100 seconds. We can call this short response reactive ability because the ground contact times are shorter.
Some people, especially strength jumpers, tend to excel more at the 1st, longer ground contact type of jump; whereas elastic jumpers tend to naturally excel at the 2nd type. This is due to the fact that the longer the ground contact times are, the more voluntary strength tends to be involved - A jump off of 2 feet with a longer amortization phase allows one more time to voluntarily apply force. The shorter the amortization phase and ground contact times are, the more that natural structure, muscle tendon lengths, and speed are going to be dominant. These rely more on involuntary rubber band like action rather than strength.
An example of a plyometric exercise that would improve longer response plyometric ability is a simple depth jump. An example of a plyometric exercise that would improve short response plyometric ability is a running high jump or full speed sprint.
Both long and short response reactive ability rely on a base of strength in order to add stability, absorb the eccentric forces created when planting, and give an athlete a bigger base of potential force ability to take advantage of.
Muscular Contributions To Each Style
It’s also worth mentioning that the muscular contributions to a uni-lateral (single leg) takeoff vs a bi-lateral (2 legged) take off are different. Both of them rely on the muscles of the glutes, hamstrings, quadriceps, and calves, yet the contribution that each muscle group provides changes depending on the style of jump. The unilateral jump relies much more on the glutes, hamstrings, and calves with the quadriceps providing a lesser role. The bilateral jump relies on the quadriceps musculature for up to 50% or more of the power output. The glutes and hamstrings are inherently fast twitch muscles and tend to be more efficient then the quadriceps when contracting at very high speeds such as those that occur in a unilateral take off. The quadriceps tend to be more efficient when contracting a little slower.
To illustrate how 2 people can accomplish the same task via different strength qualities
an athlete who is at an elite level utilizing the short amortization phase stretch shortening cycle (1-foot jump) like a higher jumper, long jumper or someone like Brent Barry, will not necessarily be proficient in performance of the other type of jump (2-foot jump) and vice-versa.
It used to be in the NBA most all of the good dunkers were unilateral 1-foot dominant
jumpers. If you ever check out some of the older NBA slam-dunk contests that run at
3:00 a.m. on ESPN classic you'll see this! Back then, because of the lack of effective training, the thought was that there wasn't much you could do about increasing the vertical jump and the guys who were good at it were naturally good at it. Nowadays, however, take a look at the best dunkers and you'll notice the 2-foot jumpers dominate. This is in large part directly due to the influence of strength training, which really has a large impact on the 2-foot jump and allows one to take advantage of their voluntary explosive strength, which is much easier developed and under less genetic influence than speed and short response reactive ability (amortization phase of around ~.100 seconds) So just because you may naturally be slow, weak, and not blessed with a great jumping structure doesn't mean you have to stay ground bound because the sky is the limit!
Although raw speed of muscular contraction and short response reactive ability is under quite a bit of genetic control and in large part determines performance in movements like the high jump and long jump; Anyone and everyone can dramatically improve their explosive strength and longer response reactive ability, which can dramatically impact
the vertical jump.
Can You Switch Styles?
So what if you’re a 2-legged jumper or a 1-legged jumper and decide you want to switch styles, is this possible? Yeah, sure you can switch from being a 1-foot jumper to being a
2-legged jumper but it may take a lot of practice at the particular style you’re less gifted in. The 2 types don’t always share a direct correlation. That is, you could for example really increase your overall 2 legged jumping abilities while at the same time not see your 1-legged jump increase much and vice versa. This is in large part due to the muscular considerations I mentioned above.
To switch from being a good 1-legged jumper to 2 legged jumper you'll have to work on strength and explosiveness, particularly in squatting type movements, along with lots of practice with the 2-legged jump.
To switch from being a good 2-legged jumper to a 1-legged jumper you will really have to bring up the ability of your glutes, hamstrings, and calves to absorb and put out energy at high speeds.
One-legged jumpers who are really good at it (high jumpers, long jumpers and some ball players) probably do have a genetic advantage in body structure and speed of contraction in the tendons, connective tissue of the lower body that allows them to be good at it naturally. A few are good at both.
Obviously, all leaping action is a combination of both general strength which is enhanced by movements like the squat, and reactive strength which is enhanced by various plyometric type exercises. The best leapers tend to have both but to varying degrees. Most of the time, regardless of structure or dominant jumping style, an individual will be more gifted towards one side or the other; ie either strength or reactivity, so his optimal training program should have him focusing on his weak points while maintaining his strengths. Barring injury, with this approach it's about impossible for improvement to ever plateau.