Strength as the Backbone
Here is a quick reminder of the importance of power production and our power equation
(Power = Force x Velocity)
You should be able to see that you can increase power either through an increase in force or an increase in velocity. However, it is generally accepted that the maximum force you put out is going to be the main determining factor for an increase in power. This is due to many reasons, one being that maximum strength is the foundation for all the other strength qualities such as speed, power etc. Think of this. If you weigh 150 lbs and your goal is to move your bodyweight off the ground as fast and as far as you can - and you are only capable of putting out 200 lbs of force, what is going to happen? If you can only squat 200 lbs then trying to move your 150 lb. bodyweight requires a significant portion of your maximum strength. You’d have to use 75% of your maximum strength just to move your own body. In this situation you’re probably not going to be moving very fast or jumping very high! Another example that may hit home – A space shuttle with a 4 horsepower motor surely won’t make it out of the earth’s atmosphere in a hurry!
Being strong just makes things easier. In the above example if you were able to put 350 lbs of force into the ground then moving your bodyweight (150 lbs) requires a lot less of your maximum strength so you have a larger strength reserve to work from. In this case you would only have to use 30% of your max strength to move your body and 30% of your maximum can be moved with greater speed and power then 75%. Make sense?
Another major consideration is that it is easier to increase force then it is to increase velocity. That is, the ceiling on maximal force or strength improvement is much lower then the ceiling on pure levels of speed. Speed has much more genetic limitation than strength does. It’s not that pure velocity or speed of movement can’t be increased, but
due to genetic factors, such as body structure, neural factors, or the number of fast twitch fibers one has, speed improvement is much more limited.
To illustrate this, many people who lift weights over a period of several years can easily double their strength in exercises such as the bench press and squat and thus double their levels of force. Yet in tests of pure speed of movement, such as the ability to tap the feet in place as many times as possible in 5 seconds, or to tap your finger as quickly as possible, improvement is much more limited.
The good thing is that in most athletic events, speed of movement does not exist in isolation, but rather is strongly related to force. Even in what would be considered a pure test of speed, the 100-meter dash, it might come as a surprise that elite level sprinters don’t move their limbs much if any faster then regular folks do! Anybody can get on their back and cycle their legs 5 times per second. Rather, it’s the amount of force a sprinter puts into the ground with each foot strike that propels them down the track at lightning speed. Each footstrike does occur quickly, yet the amount of force per footstrike is key.
When executing a vertical jump, people do change direction during their countermovements (transition from down to up) at different speeds, but in much the same way, everyone pretty much straightens their legs at the same rate of speed. The main determining outcome in the vertical jump isn’t how fast your legs move, it’s the amount of force relative to your bodyweight that you are able to put into the ground. With that said I can now give the basic vertical jump equation:
Spectacular vertical jump = High levels of force + High speed of force application
That is all there is to it! Any improvement in the vertical jump comes about through increasing one or both of those factors.
The goal of this entire program is to increase your vertical jump by increasing both of those factors.
If velocity and rate of force development stay constant, yet force levels, or strength levels, go up, you can also expect your power, and thus leaping ability, to improve as well. So how do you increase levels of force without negatively impacting the speed at which you apply that force?
Power, Scott K., and Edward T. Howley. Exercise Physiology: Theory and Application to Fitness and Performance. 8th. 2011. Print.