“Injuries are not caused by methods per se, but by the inappropriate, premature, and/or excessive application of methods.”
– Charles Staley

In all the years I’ve been involved in sports conditioning, I’ve never seen an issue with as much longevity and potential for heated debate as the question of whether or not it is necessary, safe, and or effective to perform “explosive” or “ballistic” movements in the weight room.

If you’re active on the internet, you’ll discover endless, passionate (and often, ugly) confrontations between those who advocate slow lifting speeds, and those who espouse so-called explosive training techniques, such as Olympic lifting and it’s derivatives, and plyometric training methods.

While it is true that explosively-performed (i.e., high velocity) repetitions can be potentially more dangerous than low velocity movements, it’s just as true that heavier weights, since they put more tension on the musculoskeletal system, are potentially more dangerous than lighter weights. So it really becomes an issue of using the right tool for the right job.

Remember, in order to train a biologic system, you must apply stress to that system. Too much stress leads to injury; too little leads to little or no effect; just the right amount leads to a training effect.

As you read this article, please refer to the section below which outlines the more technical terms used herein. These terms are often used inappropriately, which leads to even more confusion.

Also, please resist the human instinct to either agree or disagree with the statements I will make. Instead, simply listen. Observe. Correlate the material to your own experiences. In this way, you’ll give yourself the best opportunity to come to an intelligent decision regarding this issue.

What is Training?

Training involves the exposure of a biologic system to the systematic application of increasing stress at a frequency, intensity, and duration below that system’s maximal tolerance limit, which, over time, causes a resultant increase in that system’s tolerance limit (1).

Different training methods cause different adaptations. For example, sets lasting between 20 and 70 seconds seem to promote hypertrophy better than sets of greater or lesser duration (2). Sets performed with incomplete rests develop anaerobic capacity through a greater proliferation of capillaries in the muscle(s) being trained (3). High repetition sets develop Type I (slow twitch) fibers, while low repetition sets with heavy weight challenge Type II (fast twitch) fibers.

Long-term performance of an exercise which takes a muscle through less than it’s full range of motion promotes a shortening of that muscle, while chronic use of exercises which take the muscle through it’s full range of motion encourage the muscle to become longer (4).

These examples of the specificity principle strongly imply that the neuromuscular and musculoskeletal systems are capable of adapting to explosive movements just as they are capable of adapting to any other type of stimuli provided.

This is the real key to understanding this issue…that the athlete moves through an appropriate series of progressions which allow a sequential exposure to a gradually increasing stimulus. If you skip any part of this progression, or if you progress too quickly, injury may result as you exceed the body’s “maximum tolerance threshold” to that stimulus.

Defining the Issue

Before we proceed further, please appreciate that this issue is a difficult one to analyze, since there are several ways to lift a weight.

For example, powerlifting is not normally considered an “explosive” event, since at 1RM levels, the bar moves very slowly, due to its mass. Nevertheless, the lifter is attempting to maximally accelerate the bar. So, are we discussing the actual speed of the lift, or the attempt to maximally accelerate the weight (even if the implement speed is low to to its mass)?

Also, we must distinguish between lifting weights at a fast tempo, and lifting weights in an accelerative manner (increasing the speed over the duration of a repetition). Further, are we speaking of lifting light to moderate weight, or heavy weights?

For instance, when performing the deadlift, using a fast lifting speed with a light weight would simply reduce both the tension, as well as the time under tension, of the involved musculature, leading to a compromised training effect.

However, when deadlifting a challenging weight, you stand a better chance of making the lift if you attempt to accelerate the bar. It is important to understand that this is a smooth acceleration, not a rapid “jerk” on the bar, which would in fact, increase the likelihood of injury.

Incidentally, I define “good form” a bit differently than most. If you enter a workout with pre-determined parameters such as number of sets and reps, tempo, optimal body alignment, range of motion (which may be complete or partial) length of rest periods, and you maintain these parameters, you’re using “good form.”

So for example, you may set out to use a 2 second tempo, which is relatively fast (and may or may not be safe, depending on the exercise, your experience, the weights being lifted, and a host of other factors). However, if you set out to do a 4 second tempo, and due to fatigue or inattention it ends up being a 2 second tempo, this shows a lack of control, which in my opinion, heightens the potential for injury.

So, although many people cite the dangers of “fast” or “explosive” lifting, I hope you can now appreciate that the issue is far more complex than most people consider. During this article, I will make reference to explosive, ballistic, and accelerative lifting techniques, in an effort to cover the various possible methods.

Is Accelerative Activity an Inherent Characteristic of Human Movement?

The phenomenon known as the stretch-shortening cycle (or SSC) strongly hints that the body is, in fact, designed for ballistic and accelerative stress (5).

To illustrate this concept, I’ll ask you to imagine the act of throwing a baseball, overhand style.You grab the ball, extend your throwing arm behind you, and, just as the arm nears complete extension (the eccentric portion of the throw), you rapidly reverse the motion (the concentric phase) and release the ball.

Now, just as an experiment, extend the arm back, and pause for three seconds before you throw. It’s intuitively obvious that the second throw, aside from feeling totally unnatural, will travel much slower and result in a shorter throw.

When you throw (or jump, hit, etc) correctly, the musculo-tendinous unit stores potential kinetic energy during the eccentric phase of the movement. At full stretch, the muscle begins its reversal into the concentric phase. If you use proper timing (the “switch” between eccentric and concentric must be very rapid), you can recover all that potential energy and return it during the concentric phase. If you wait-even for a split second- the energy will dissipate.

A simpler way to visualize the SSC is to imagine the muscles as elastic bands that stretch during eccentric activity, and contract during the concentric portion of the movement. (Incidentally, plyometric training programs, usually consisting of various jumps and throws, are designed to train the elastic potential of the musculoskeletal system.)

If you watch people carefully in various situations, you’ll notice that, whenever there is an option to accelerate a load, people will take that option.

On stairclimbing machines, people will, especially as fatigue sets in, tend to step in a bouncy, choppy manner. When a heavy box must be lifted from the floor to a high shelf, a person will accelerate the box throughout the lift.

Further, the motor cortex will normally choose a movement pattern where more muscle groups can participate in the effort, in order to conserve energy and avoid dangerous levels of stress to any single muscle involved in the movement.

Optimal Progression Ensures Safety

Now the question becomes “If this is how muscles work in everyday activities, should we train muscles this way?” My colleague Paul Chek often asserts that “First isolate, then integrate.” What Paul means by this is that before asking the chain to produce high levels of force, one should first strengthen each link of the chain, especially the weakest links.

When training a link, you must “isolate” that link…in other words, create a movement or exercise where associated links have no ability to assist in that movement.

Since muscles are the links in any kinetic chain, another way to view this progression is to “First, train muscles, then train movements.” Either way you choose to conceptualize it, most accelerative lifting movements (such as modified Olympic lifts such as power cleans & snatches, push-jerks, jumps, throws, etc.) involve large numbers of muscles.

Therefore, if these individual muscles are brought to maximum strength levels prior to accelerative, multi-joint movements, the athlete lessens the potential for injury. However, if any link in the chain is relatively weak, that link would logically have a greater potential for injury during any explosive type exercise that involves it.

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