Analysing the one-leg jump, part VIII: Speed

We’ve been all around the body of a one-leg jumper so far: muscles, tendons, joints, collapse patterns and understanding what makes them, and so on.

Strength has been, so far, a pretty important topic. And it’s been so because IT IS the foundation of all the other qualities. I want now to talk about SPEED. But before I do it, I want to quote some smart people talking about how important strength is for speed:

Verkhoshansky and Siff (talking about depth jumps):

If the momentum forces your heels to the ground, the box height is excessive. Siff stresses the need for eccentric strength, which is built with squats.


Squat in between 150 and 200% of your bodyweight before engaging in depth jumps.

Dan John:

If you haven’t built the foundation, don’t paint the ceiling.


Maintain strength once you get to 2X squat, or else the performance will suffer.


Enhance maximal strength. It is impossible for athletes to generate a large force in a fast movement if they cannot develop similar or even greater forces in a slow motion.

As you can tell from all these quotes, strength is of utmost importance. It also is the foundation of other qualities such as explosive strength, reactive ability or speed. And that is the reason why we’ve spent so much time analyzing the strength aspects of the one leg jump, even though the one leg jump is much LESS strength dependent than the 2-leg jump.

Well, OK, but what about speed? As strength is less important in the one-leg jump, something has to take its place so that we can get up there in our jumps. So what is the quality that compensates for the lack of strength that one leg has vs two, in the case of a two leg jump? Well, that quality is speed.

When you have great speed in your one-leg jump, you compensate for the lack of strength by taking away some of your bodyweight with the energy, momentum or power (whatever you want to call it) that you’ve accumulated during your run-up. So, in essence, you weigh less. Your muscles have less work to do because of this, and if you combine less work to do with better leverage to do that work upon (the one-leg long, straight lever vs. the two-leg bent lever in a two-leg jump), then you’re going to jump high.

Obviously, these things must obey what we’ve already discussed, and they occur IF you don’t collapse during your plant. You can have all the speed in the world – if your leg collapses when you plant it to jump, you won’t jump. There’s no way around it. Considering this – all we’ve already talked about in this series has to happen in order for proper speed application in the jump to occur (you have to have the strength and the right tendon properties to benefit from the accumulated speed).

You can still jump and dunk off one leg if you’re a “strength one leg jumper”, though, but it won’t be optimal. For example, I can dunk on 10 feet with just two steps, and sometimes even one step (I pivot on my right leg, put the left leg and jump off it).

How? Because I have enough voluntary power to combat the lack of speed and tendon contributions that I lose by not having momentum. So, in essence, strength gets you out of a lot of trouble.

Anyway, enough with this babbling around, let’s get to work.

What exactly IS speed? Well, I would define speed as a combination of quickness and strength. Quickness is something that is on the genetic realm of things. It is something that is almost not at all dependent on strength and almost completely depended on the CNS ability to mess around with contracting and relaxing muscles, and doing so at high speeds. Examples for this are quickly tapping your finger on a key, shaking your arm at very high speeds, doing go-stop stopwatch games (where you start a stopwatch and stop it as fast as possible and see how fast did you manage to do it) etc.

As you can see, these things are almost completely NOT dependent on strength. You can be as weak as anybody and still be really, really quick. Why? Because all these actions don’t depend on the muscles moving a “heavy” object, where “heavy” can be your bodyweight.

When you jump, or sprint, or do plyometric stuff, or squat, or clean, or whatever you do that has some resistance to be moved (either in the form of a barbell, kettlebell or your own bodyweight), then muscles have to overcome that resistance in order to perform the movement. You can have all the quickness in the world to stimulate these muscles – if the muscles are weak, they won’t be able to do it because doing that movement requires a high % of their maximal strength, and doing work in the high % range of maximal strength is going to be slow.

Let me requote again:


Enhance maximal strength. It is impossible for athletes to generate a large force in a fast movement if they cannot develop similar or even greater forces in a slow motion.

So, in order to generate speed you have to be strong and you have to be quick. Luckily, quickness is not that important until you reach a very high level of strength, at which point the difference between you and Genetic Freak Athlete X is really going to be his CNS being better than yours, or him being quicker.

Now let me quote McGill:

Jumping requires a tuned balance of variables: strength, speed of contraction and relaxation, direction and precision of force application, tuning of stability/stiffness at some joints, with compliance and mobility at others etc. When muscles contract, they create both force (influencing strength) and stiffness (influencing speed). Stiffness slows motion. Power production and jump require speed and strength, but these two variables compete with each other. Strength is needed to propel, but to enable strength to convert to speed, relaxation is needed to mitigate the associated stiffness. Thus, the jump is actually a measure of the ability to “pulse” and will be defined or bounded by both the rate of muscle activation AND relaxation. Strength without rapid pulsing will never create an impressive jump. Of course, rate of muscle dynamics is bounded by physiological processes but also neural and biomechanical.

There you have it – strength, as much as it is important, IMPAIRS speed. But how can that be? We spent all this time talking about how important strength is to all the other qualities, including speed, giving a ton of quotes to back that up, only to come and seemingly contradict all we’ve said.

Well, not really. You see, strength is “bad” for speed only when it is trained, or enforced, in competition with speed. That is the reason why when you squat a lot you seem to be less reactive (and, in fact, you ARE less reactive) and also slower. It’s not that strength is bad (by any means), it’s that it competes with speed when they are both being trained at high volumes. Strength means tension. When you strength train you create a toned-up effect on the muscles, with the muscles being under MORE tension even at rest. And since tension is influencing speed in a bad way, and relaxation influences speed in a good way, being tensed all the time means being SLOW all the time.

In a perfect world, you want to be strong with the ability to use that strength only when needed. In all the other cases, you want to be relaxed. This is what you could also define as movement efficiency.

This is another reason why, if you stop strength training, you find all of the sudden that, 1-2 weeks after stopping your heavy strength training (squatting heavy etc), you become more “reactive” or “elastic”: the toned muscle effect decreases and you are able to be more relaxed, and you become FASTER. You also don’t lose strength all that fast, so you’re still strong, and you’re also recovered better, and you DISPLAY your actual real power.

So, remember, in order to be powerful and fast, you need to prioritize that and limit the volumes of strength training for that period of time. Something like 5×2 or 2×5 with the last set being still very fast and light is paramount for this. Train much, much more under the margin of failure during the times when you want to maximize your speed, jumping, dunking etc.

If you can squat 2×5 with 100 kg, do 2×5 with something like 80 kg. I personally go to a top set of 5 with a weight that my last rep of the set starts to KINDA slow down, and then take 10 kg or so off the bar and do another set with that weight. So, maximal “freshness” if you will, nothing close at all to failure.

Keep grinding reps and close proximity to failure during the times when you want to push your maximal strength up, and when speed and reactive ability is not important (in my case, during winter, since I don’t have a place to jump or sprint then anyway).

Hoping that you learned something new from this article, stay tuned for my next article soon.

Take care,


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