Sunday, April 7, 2013

Programming Your Master Computer for Jumping







Jumping With a Weighted Sled

The next step to manipulating the CNS (central nervous system) is to prevent it from antagonistic muscle contraction and muscle recruitment inhibition. I know that probably sounds complicated but its really easy to comprehend.  An antagonistic muscle is the muscle opposite the one contracting.  For example, if you’re doing a pulling movement the antagonistic muscles would be the pushing muscles on the opposite side and vice versa.  If you were doing a bicep curl, the antagonistic muscle would be the triceps, which is the muscle on the back of your arm.  Normally, when contracting a muscle, some tension is maintained in the antagonist muscle and this decreases the forcapplication of the working muscle.  Try this out for yourself.  Try to do an arm curl while also contracting your tricep muscle as hard as you can.  When you perform a high-speed movement with a lot of force and power your body will exactly that to a certain extent.

What happens in this situation is your master controller (CNS) tries to work against you by pushing while you pull.  Its largely a protective mechanism to prevent you from injuring yourself and also occurs because you havent trained your CNS to relax completely when moving at high speeds.   This is like running with a weighted sled attached to you. Any weight you can remove from that sled will instantly make it easier to go the same speed or in the case of the vertical jump, make it easier to go higher. For another simple example of this, tap your hand on a desk as fast as you can for 10 seconds straight.  Did you find it difficult to avoid tensing up?  If so, thats because you were unable to completely relax in between taps.

Being able to put out a lot of force is very useful but being able to relax completely is just as important for any high- speed movement and the vertical jump certainly qualifies here. In fact, the key characteristic of world-class sprinters is their ability to completely relax between strides. Lower class sprinters will maintain lots of tension in the antagonists yet top sprinters relax completely which enables them to go faster.  Training methods such as energy absorption training and reactive methods done at high speed with an emphasis on relaxation can teach your system to eliminate antagonist contraction.


The end result after implementation of these training methods is a very smooth and powerful contraction of the muscles involved and a relaxed flow to the movement. Eventually, when you apply maximum force at high speed the antagonist muscles are coordinated in such a way that they dont contract to oppose the movement, which automatically means increased performance.   Have you ever noticed how most of the best jumpers, or athletes in any field, appear to be so relaxed and perform with such ease and grace that they make what they’re doing look easy? They leave the ground smooth and relaxed without any unnecessary muscle involvement. This is just one of the effects of an efficient nervous system. Contrast this to the guy with a 15-inch vertical jump who looks like he’s about to have a conniption when he jumps!.

Programming Your Master Computer

Now the most important part of CNS manipulation. The nervous system normally prevents you from fully activating all of your muscle motor units in a particular task. Yep, not only can it make things difficult when you want to move effortlessly, it also prevents you from exerting all of your potential force in a given movement!

If you were to take a muscle and hook it up in the laboratory to a special measuring device you can accurately determine how much force that muscle is potentially capable of exerting. This figure is the definition of absolute strength and is the maximum amount of force you could apply if you were able to voluntarily contract all motor units in a muscle. Potential is big here because it turns out most folks aren't able to use anywhere near the potential force their muscles are capable of exerting. In fact, untrained folks might only be able to voluntarily put out around 50% of their potential absolute force in a given task. Trained athletes with years of experience can approach 85-90%.

The nervous system inhibits you from using all your potential strength in 2 ways. First, exerting all your voluntary force and getting all your muscle motor units turned on requires strong and efficient neural (electrical) signals emanating from the brain and spinal cord.  These signal your muscles to turn on and exert force. The more efficiently this process works the more muscle fibers you can fire and the quicker you can turn your muscles off and on. However, the reason your body makes this difficult is because if you were able to voluntarily turn on all your muscle motor units you'd stand a good chance of ripping your muscles right off the tendon!   Therefore, the body naturally protects” or inhibits you from doing this. However, it is possible to condition your body to push this natural inhibition back with proper training and this is why trained athletes are able to use more of their potential ability than sedentary folks. This also partly explains why some small guys are exceptionally strong and powerful, while some large guys are weak.

Second, and this example will be more specific to jumping, eccentric stretching brought on by plyometric activity (which leaping inherently relies on) causes the muscles and tendons throughout your lower body to stretch and quickly store energy in the tendons like a spring. When this energy is released it causes a reflexive, or involuntary contraction that can increase force output more than double what youd get through voluntary force output. The faster the speed and more forceful the stretch in reactive/plyometric activity the greater the level of force in the subsequent contraction which is why we instinctively use plyometric contractions in just about everything we do (rearing the arm back to throw, dipping down prior to a jump etc).

However, most are not able to fully take advantage of this because the muscle/tendon complex has proprioceptors. The job of a proprioceptor is to monitor the degree of the eccentric stretch and prevent overstretching and injury by basically shutting the muscle down when the stress or stretch is too great. The problem is, sometimes these proprioceptors kick in sooner than you would like and they inhibit you from taking full advantage of your reactive, or plyometric capacity. So, they prevent you from injuring yourself but also prevent you from fully utilizing all of your potential power output.  

To illustrate this for yourself perform a simple vertical jump from the floor (down and up) and measure the height you jump. Next, find some aerobics step boxes about 6-8 inches high and stand on one, step off, and as soon as you hit the ground immediately jump as high as you can and again measure the height you jump. The large majority of you will notice you can jump higher when stepping off the box then you can from the floor. This is because when you step off the box you increase the rate and the force of the eccentric stretch in your lower body muscles and tendons at ground contact - so your muscles responded with a stronger reflexive/reactive contraction, which caused you to jump higher. Notice you didn't have to really try any harder, the added force just kind of came reflexively, which is what plyometric strength is all about.

Next, keep increasing the height of the boxes until you find the point where your jump after ground contact begins to decline. For some this might be 8 inches, for others 15, for others 25 inches or more. Wherever that point may be it signifies the point where the force of the eccentric stretch begins to cause your proprioceptors to kick in and cause muscular inhibition. Fortunately, this can be trained and improved - an increase will translate into increased jumping prowess. 

Examples of Superhuman abilities

Under extreme circumstances, such as life and death situations, adrenaline causes the nervous system to send stronger then normal electrical signals to the muscles and proprioceptor inhibition is largely removed. This allows nearly all the muscle motor units to turn on and nearly 100% of one's strength and force potential can be utilized. Have you ever heard stories of 110 lb women lifting cars off of children? Have you ever been chased by the cops, an attack dog, or anything else that scared the living daylights out of you and noticed how much faster you ran!? Have you heard stories of people on PCP or other drugs being able to bust out of straight jackets and handcuffs? These are all good examples of manipulation of the nervous system. Because of the apparent life or death situation, inhibition is removed and all the muscle fibers are able to fire with the outcome being apparent superhuman strength, force, and power. Unfortunately, the people who accomplish these tasks often end up hurting themselves because of what I described above.  The muscles are potentially strong enough to rip the tendons right off the bone!


Here's another less dramatic example of this. Have you ever noticed how you can jump quite a bit higher and run faster whenever you're feeling really energetic, fired up, or maybe even anxious? Most players notice they can "get up" better or move faster in a game or even prior to a game when their adrenaline is pumping. This is because the increased adrenaline allows you to fire more muscle then normal and thus produce more force and power. One of the main objectives of this program is to learn to eliminate CNS inhibition without needing an adrenaline surge or life or death situation to do it! Imagine what would happen if you went from using 50% of your force capacity and you suddenly increased that to 100%? The results would be very, very impressive to say the least!


Sources:  

Schmidt Richard, A., and D. Lee Timothy. Motor control and learning: A behavioural emphasis. New York, NY: Sheridan Books, 2005. Print.


Magill, R. A. Motor Learning and Control, concepts and applications. 9th ed. New York City: McGraw-Hill Humanities/Social Sciences/Languages, 2011. Print


McArdle, William D., Victor L. Katch, and Frank I. Katch. Essentials Of Exercise Physiology. 4th ed. 2010. Print.