A friend of mine wrote is.. So I give Josh Henkin credit.. very smart bro..

It seems impossible to workout in a gym, pick up a muscle magazine, or watch the local news and not see the dangers of exercise being discussed. This is extremely unnerving to those that spend a great deal of time researching and understanding the science behind physical conditioning. This is kind be very confusing to the average person that is told to exercise, but also so scared to hurt themselves they end up doing very little to improve their health. This article provides me an opportunity to dispel some of the more common myths about the various dangers of training.

Certain Exercises, Stretches, and Methods are Dangerous:

So many people try to use the scare tactic to have others believe their system of training is superior to another. When in fact, all methods, exercises, and forms of stretching have a place in any training program. Sure, some of these ideas may have a higher “risk” associated with them, but with proper instruction and implementation utilizing these methods can better prepare an individual for the demands placed upon them by their sport or activity. Here are a few examples:

Full Squatting is Bad for the Knees

Believe it or not in my years studying at the university this was a universally accepted rule without any debate upon why. This myth has its roots in a 1957 study by researcher, Karl Klein. In 1961, Klein presented his research on the dangers of squatting to the American College of Sports Medicine. Since then many people assumed all the dangers of squatting were true. This is very surprising because many studies have tried to reproduce Klein’s studies and have found his experimental method to be seriously flawed and no current studies have been able to reproduce his original results. Interesting how in spite of the numerous studies that contradict and dispute Klein’s original study many in the health professions are still hesitant to prescribe full squatting. This is a shame considering Olympic lifters have been using full squats with extreme loads for decades and have minimal knee or back injuries.

Ballistic Stretching Will Tear Your Muscles
Ballistic stretching is a form of dynamic stretching which can be defined as a form of stretching, which “imposes passive momentum to exceed static ROM on (a) relaxed, or (b) contracted muscles (Siff, 1995).” Most think of ballistic stretching as bouncing in a specific stretch; while this may be true to a point other forms exist. For example, in a traditional leg swing for the hamstrings, both the speed and amplitude of the movement can be slowly increased to improve the range of motion. So, progression is a key component in this as well as other forms of stretching. How does this relate to danger though? In it very interesting to note that tissues respond differently to different forms of loading and training. Therefore it reasons those that are going to be called upon to perform ballistic actions, which really is all of us, should be exposed to various forms of this method to prepare the tissues for the specificity of the actions. All those that scream, freak, and yell over the use of ballistic actions both in training and stretching need to realize that the forces created by running, jumping, and throwing are so much more significant to the body and can produce a greater environment for injury.

Lifting a Weight Fast Means you are OUT OF CONTROL!!!

Countless times I have heard from trainers, coaches, and the general public that one must lift a weight slowly. This is assumed to be safer and better to train muscles. Those against fast lifting often state ideas such as:

Momentum will cause one to become injured.
There is no transfer to sport as strength is strength.
Tension on the muscle is low.

While a great deal of time can be spent arguing each of these points lets take a quick look at each one to more clearly understand the problems with such logic.

“Momentum will cause one to become injured”

First it is important to understand what is momentum. We can refer to biomechanics to find momentum is equal to Mass (in this case load) times velocity. This is relevant because we can see that as weight is increased velocity decreases however, there is still momentum. The same situation can be taken for a lighter weight being moved faster. Now instead of load increasing we have increased velocity, again there is momentum. Very quickly one should be able to realize that momentum occurs with every movement and can occur at high levels even if the weight is moving slowly. It is when momentum is changed rapidly that one can be at a risk for injury. In addition, most injuries in lifting occur in the beginning phases of lifting a weight when one is trying to overcome inertia. Hmmmm....interesting.

“There is no transfer to sport as strength is strength”

Oh, if it were only this simple. When movement occurs, especially against a load, there are several forms of strength that allow such a movement to occur. We have starting strength, acceleration-strength, rate of force development, explosive strength, maximum strength, strength-endurance, and deceleration strength. We could even break down different components of strength further, but I think the point is clear. Strength is just not how much one can lift. In terms of sports production how much one can lift can be irrelevant if the ability to produce a certain amount of force in a brief period of time is not developed (Rate of Force Development). Methods such as Olympic lifts and polymetrics are often employed in training programs to improve an athlete’s ability to produce force quickly. It is obvious that if an athlete cannot produce a great level of force within the time frame of the sporting action their performance is going to suffer.

“Tension on the Muscle is Low”

This idea must stem from the bodybuilding world which often believes moving a weight slowly increases the amount of tension on a muscle. This is not fully true, if we examine again what tension really is, it quickly becomes apparent there is a great deal of fault with this assumption. Tension, also known as force, is Mass (again load) times Acceleration. So, this gives us two ways to produce high levels of tension. We can use a large weight and try to move it quickly or use a lighter weight and move it quickly. This means the magnitude of the tension is higher than lifting a smaller weight slowly. The duration of this tension might be lower, but research has yet to prove if smaller tensions for a longer duration are superior to higher tensions for a brief duration.


By this point it should be obvious just because an “expert” warns against doing a particular movement or method, everyone should avoid it like the plague. What we should be really considering is the appropriateness of incorporating these methods into various programs. World Renowned Sports Scientist, Dr. Mel Siff, has outlined the following points that can help determine the level of appropriateness of various ideas.

Directions of use
Special Precautions
Symptoms of misuse
Treatment of misuse
Dependence on therapy