A Rationale for Strength Training.

THOUGH MODERN strength training has a history of more than a half-century of scientific progress, its coaches continue to disagree over the best way to develop power or "explosiveness" in the athlete.

Thanks to contradictions in the literature and research studies, strength training remains the province of two different groups of professionals: a traditional ballistic group and a nontraditional, anti-ballistic group.

The traditional group believes in resistance training that emphasizes fast movements, acceleration, and momentum through such exercises as cleans, snatches, push jerks, push presses, and traditional plyometrics.

The non-traditional group believes in "slowing down" the resistance training and emphasizing higher muscular tension and maximum overload by working to the point of muscle fatigue. Whatever ballistic training it employs is relegated to activities outside the weight room, such as agility-type drills, sprinting, and the practice of specific sport skills.

Because of the on-going debate between the two groups and the absence of a single definitive method of enhancing muscular power, it is doubtful whether the controversy will be resolved in the foreseeable future.

I believe that a spirited discussion and an exchange of ideas can be valuable in educating, enlightening, and hopefully improving the level of respect between the two camps.

I have established six criteria by which to compare the traditional and non-traditional groups in training for power and explosion:

1. Muscle recruitment principles.

2. The speed of the movement.

3. Specificity of training/transfer to sport skills.

4. Olympic lifting and plyometrics.

5. Practicality/reality.

6. Injuries/long-term wear and tear.

Physics of Power

Prior to any comparison of the two approaches to training for power and explosion, I believe a basic review of the physics of power might help keep the discussion in perspective.

Although it can be somewhat confusing, the physics of power can be broken down into three major objectives:

1. Increasing the strength potential of the muscle.

2. Increasing the distance over which the strength or muscular force is applied.

3. Decreasing the time in which the force has to be applied.

Resistance training in the weight room will improve the athlete's muscular strength. By increasing the flexibility of the joints and then practicing his actual sport, the athlete can increase the distance over which he can apply muscular force.

Many people believe that the time in which the force must be applied can be reduced in the weight room via specific resistance training exercises or via the traditional plyometric drills. Not surprisingly, most traditional strength and conditioning programs are based on this premise.

Another logical way with which to reduce the application of force (strength) is offered by the non-traditional approach to power enhancement. Simply put, it involves the use of non-ballistic resistance training to increase muscular strength, then training the nervous system to act as fast and as efficiently as possible by practicing the specific sport skill exactly as performed in competition.

Obviously, you are not going to create a lot of excitement by advising your athletes to increase their strength in the weight room and then go out and practice their sport skill to become more powerful. But it is a reality-based philosophy that forms the basis for the non-traditional group's view on power development.

Let's examine the aforementioned six criteria as viewed by the traditional and non-traditional groups.

Muscle Recruitment Principles

Although various classifications are used, individual muscle fibers can generally be divided into one of three types -- Type 1, 2A, and 2B.

Type 1 fibers have more endurance, but have less force-generating capacity than Type 2A and 2B fibers.

Type 2A fibers are considered intermediate fibers. They possess both moderate endurance and moderate force-generating potential.

Type 2B fibers fatigue faster, but are capable of generating greater force than either Type 1 or Type 2A fibers.

A group of fibers innervated by the central nervous system is called a motor unit. We thus have Types 1, 2A, and 2B motor units (MUs).

In accordance with Hennemen's principle, whenever you perform any activity, MUs are activated or "recruited" in an orderly manner. They are recruited sequentially from low to high threshold as force requirements increase.

The lower threshold Type 1 MUs are recruited first, then, if necessary Type 2A, and finally the higher threshold Type 2B MUs. Whenever Type 2B MUs are recruited, a very high percentage of all MUs are working.

The magnitude of recruitments all depends upon the type of activity and length of time it is performed. For example, when doing a low-level activity such as walking, the Type 1 MUs are recruited. Because walking is of low demand and can be done literally for hours at a time, Type 1 MUs can fuel the efforts without the help of many Type 2 MUs.

A different scenario is used in strength training. Strength training becomes a short-term, anaerobic activity because significant resistance is used and a high intensity of effort is required. Therefore, although Type 1 MUs are initially recruited when lifting any resistance, the Type 2 MUs must be recruited due to the higher demand that is created by proper strength training.

The Type 2 MUs then become the critical motor unit type (first Type 2A, and, if needed, Type 2B) to successfully complete an exercise set.

Since, however, Type 2A and Type 2B MUs have less endurance capacity and fatigue at a greater rate than Type 1 MUs, they cannot contract for a long period of time. Type 1 MUs alone cannot meet the demands of the exercise set, and so it must be terminated.

In short, you cannot lift a significant amount of resistance for a high number of repetitions or for a long period of time.

Proper strength training, therefore, boils down to targeting and overloading the Type 2 MUs, especially Type 2B. To recruit, fatigue and overload the higher-threshold, greater force-generating Type 2B MUs, it requires the athlete to apply significant resistance, maximum muscular tension, and maximum effort.

A properly performed exercise set is, therefore, one that:

1. Is performed with a significant tension-producing resistance.

2. Is lifted with a deliberately controlled movement speed.

3. Is taken to the point of momentary muscular fatigue to recruit, exhaust, and overload a maximum number of MUs, especially Type 2B.

Implications

For the Traditional Group:

A key distinction of the traditional group is its use of Olympic lifts and their variations. A high level of momentum is often exhibited in these lifts, which can reduce the muscular tension and the total muscle involvement -- increasing the potential for muscle or joint trauma.

Most traditional trainers do, however, employ slower-moving exercises and prescriptions in their training regimens that do recruit a greater number of MUs in a safer manner.

Others in the traditional group do not advocate nor prescribe exercise sets being taken to momentary muscle fatigue. This can limit the number of MUs recruited in an exercise set and decrease the maximum potential overload. For the Non-Traditional Group:

Most non-traditional trainers base their exercise programs on a slower, more controlled speed and work each set to momentary muscular fatigue. The cornerstone of their program is maximum unit recruitment with a high-intensity effort over a full range of joint motion.

This optimizes the recruitment of the Type 2A and Type 2B MUs needed for increased power potential.

Minimizing the momentum and accelerative forces will additionally reduce the potential for muscle and/or joint trauma. Without question, this is a valid basis for establishing a non-traditional program.