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Ballistics or Baloney?

December 14, 2005 10:14 AM

According to Dr. Mel Siff, "Ballistic movement comprises bursts of muscular activity followed by phases of relaxation during which the motion continues as a consequence of stored limb momentum or elastic energy." Dr. Siff used this definition of ballistic movements specifically to differentiate them from co-contraction movements which have a simultaneous contraction of the "agonistic" and "antagonistic" muscles. He later describes the antagonistic portion of ballistic movement as eccentric contractions limiting the range of joint movement at the end of the activity

Additionally Siff stated, "ballistic movements require the brain to determine every detail of the action in advance by mentally planning the exact sequence of neural activation for numerous individual muscles." The reason for this is that ballistic actions do not have any feedback mechanism to provide information to the brain which allows for performance of the activity at much faster rates of speed. Running, throwing, and jumping are all ballistic actions used in sport. Olympic lifts are considered ballistic exercises.

Despite mixed opinions as to the safety of ballistic weight training versus training at slower speeds, ballistic (or explosive) exercises are widely recommended for sports training. I'm not going to address the issue of safety in this article because I believe there are other important issues regarding the effectiveness of ballistic strength training that should be addressed before a risk/reward ratio can be expressed.

The most common reasons for recommending ballistic/explosive training are first, a commonly held belief that ballistic exercises have elements of movement specificity (they mirror movements required during competition). Second, the belief that speed of the lift will translate to faster limb movement, and finally, economy through efficiency.

Movement specificity relates to muscle recruitment patterns necessary during competition. The Olympic C&J, the power clean, and the Olympic Snatch are considered examples of explosive/ballistic exercises, yet in relation to faster running, I can neither recall any athlete carrying a loaded barbell to be thrown into the air while running nor can I recall seeing any runner grab a bar off the track surface, drop into a crouch and raise it overhead in a single motion. But, perhaps I'm getting old and the memories are fading.

The nearest event that I can recall matching muscle recruitment patterns of these exercises is?the Olympic Clean-&-Jerk and the Olympic Snatch!

If Dr. Siff's statement that ballistic movements require mentally planning the exact sequence of neural activation for numerous individual muscles is correct, how beneficial is ballistic training where there is no exact match - such as faster running?

What about the speed element of performing a ballistic movement: creating faster limb movements? The speed of limb movement will never be as fast when limb muscles are loaded as when they are not loaded. If the training load is equivalent to, or less than, the load used in the performance of the sport, it would be better to practice the sport. If the load in training is greater than the load during performance of the sport, then how much greater should the load be for maximum effectiveness?

To move a weight as fast as possible means that the weight must be relatively light for the motor units and the existing density of myofibrils within the muscle fibers to move explosively. The initial propulsion of the weight must recruit motor units large enough to overcome inertia and to increase the speed of the lift.

In other words, you must be strong enough to overcome inertia. If you have previously packed muscles through myofibrillar hypertrophy, they should be ready to perform with the lighter weight. But to move increasing amounts of weight faster, you must get stronger. Which doesn't come solely from moving weights faster.

Heavy weights in the 90%-100% 1RM range can only be moved slowly. However, what you see on the outside does not match what is happening on the inside. What occurs in the neuromuscular system is the equivalent of the field commander's tent during a heated battle. Calls have gone to the central command to recruit additional motor units; only the largest of which will do since it isn't clear how long or how often this heavy weight will be lifted. The myofibrils in all of the fiber types are fully involved and working, their motor units firing them at full speed to keep the heavy weight moving. The weight is moving slowly but the motor units are firing as fast as they can, the larger motor units firing faster than smaller ones, to provide the necessary strength. All the new recruits will be trained and ready to work when it's time for competition if command central believes that there will be a continuing demand for the larger motor units and more myofibrils. When the amount of weight is reduced, there is sufficient strength to overcome inertia and to move the weight significantly faster.

What about economy through developed efficiency as a reason for ballistic training?

Dr. Siff stated that, "ballistic action relying on short-term storage and release of elastic energy (potential energy of stretched tissue) has been shown to enhance movement efficiency in locomotion and many other movements, thereby lowering the energy cost of many activities. Thus, all running, throwing, jumping, and lifting in all sports relies very heavily on ballistic action."

Most coaches would agree with that.

However, the short-term storage and release of elastic energy is also a definition of plyometrics, yet plyometrics do not fit the definition of ballistics provided by Siff since the eccentric contraction occurs prior to the concentric contraction.

In addition, plyometrics often require significantly less strength to overcome inertia.

The basis of plyometrics most likely occurred during the 1960's when a number of studies were done by Margaria of Italy, Zatsiorsky and Verkhoshanski of Russia, and others. Additional studies throughout the 1970's and 1980's showed mixed results as to the effectiveness of plyometric training.

During the 1990's, new studies by Adams (1992) and Newton and Kramer (1994) showed improved results when plyometrics were combined with resistance training. Radcliffe's 1994 study combined weight training and plyometrics in the same session. As research continues, plyometrics appear to be bridging the gap between strength and power.

Both ballistics and plyometrics are training methods that apparently help convert the effects of strength training into usable power.

So is it plyometrics, or ballistics, or both?

Each coach must decide the answer to the question and that decision should be dependent on a variety of factors, not the least of which is the specifics of the sport they coach.

In our strength training program we have eliminated ballistic exercises such as power cleans, clean-&-jerks, and push presses. Admittedly, that was a sad experience for me, having been raised on a steady diet of power cleans and push presses throughout my competitive years and well into my coaching experience: a total of 33 years.

The main reasons for eliminating these ballistic lifts were the lack of movement specificity, the load-time factor when performing the lifts (see the article "The Holy Grail Of Speed Training"), the increased probability of injury, and most importantly for increasing speed: The contact time differential.

For runners, contact time is critical. Increasingly greater ground force application peaks at minimum ground contact time; different for each runner but affecting all runners. Compared to the amount of ground contact time available to release elastic (or potential) energy during high speed running, Olympic lifts and their derivatives are more snail-like than ballistic. The common forms of ballistics use significantly longer contact times than sprinting allows. The positives of ballistic training are not attainable at top speeds.

Plyometrics describe the rapid change from an eccentric stretch to a fast concentric contraction. The faster the change, the greater the tension in the contracting muscle. That tension aids in creating power. Lots of explosive power!

Do plyometric exercises have movement specificity equivalent to running?

Not all of them do, but several of them are a very close match to what occurs during high speed running. Depth jumps and single leg hops are closely associated to how we run fast.

Stepping off a box then rebounding as quickly as possible upon ground contact is similar to the action that occurs as we approach top running speed. In both cases, bodyweight plus gravity stretch the muscles and tendons eccentrically (the forced dorsiflexion of the foot is a factor in stretching in both cases) followed rapidly by a concentric contraction. Raising the height of the box can increase the stretch because of gravity's effect on bodyweight, but it is not necessary to exceed 39-40 inches.

To those in the sprint coaching community who believe some proper angle of foot dorsiflexion is an element of training that must not be overlooked: What is the proper angle of dorsiflexion?

If you are not sure, here's an excellent way to find it: Lay on your back with your right leg lying on the ground and your left leg raised and perpendicular to the floor. Dorsiflex your left foot (bend your toes toward your head) as much as you can. Hold that position for 1/10 of a second, then relax.

Repeat, but this time during the 1/10 of a second that you hold the angle you believe to be correct, have a friend drop a 350 lb. boulder on your dorsiflexed foot.

Were you able to hold the same angle of dorsiflexion?

Assuming you weigh 150 lbs. and you are a trained sprinter, that boulder represents somewhat less than the amount of ground force applied (up to 3 times bodyweight) when you approach top speed. Any attempt to institute perfect dorsiflexion prior to landing will have minimal, if any, effect on sprint mechanics and speed compared to the effects of gravity and bodyweight.

Plyometric training, as with any other training, must be performed within the limits of safety and effectiveness since they have the potential to cause injury if performed improperly or excessively.

We believe our athletes should finish the strength training portion of their workout feeling exhilarated, not exhausted. Since dropping ballistic type exercises from our program, we have reduced the amount of time our athletes spend on strength training to approximately 75 minutes (at least half spent resting) without reduction in speed or power.

Our goal has been to increase strength and power. We continue to see the same increases in both despite removing ballistic exercises.

And that is exhilarating!



Barry Ross has been coaching for more than 25 years, initially a track and field throwing events and general strength training coach. His focus in the last 10 years is on increasing the strength and speed (power!) of athletes in a variety of sports including football, baseball, volleyball, basketball, tennis, rugby, cross country and track. Coach Ross has had a solid percentage of his athletes receive NCAA Division 1 and 2 scholarships in a variety of sports (including volleyball, football, soccer, and track) at UCLA, San Jose State, U.C. Berkley, University of Southern California, UNLV, Washington, and the Naval Academy. Among his most well known athletes are Jessica Cosby, winner of Pac 10 titles in the shot put and hammer, as well as a NCAA Division 1 title in the shot put and Allyson Felix who, as a 17 year old high school student in 2003, broke all of Marion Jones high school records in the 200 meters and went on to run the fastest 200 meters in the world that year. Ms. Felix also became the first track and field athlete to go directly from high school into professional track. His strength training methods are used by high schools and college athletes as well as professional baseball, tennis and rugby players.
Barry has recently released the book, Underground Secrets To Faster Running, describing his training methods as well as the science behind them. He can be reached at www.bearpowered.com
 

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