Guiding principles in the strength-training philosophy.

The 14 basic scientific concepts from which to choose your protocol

Strength coaches have many philosophies from which to choose a protocol, such as high intensity, BFS, single set, multiple set, periodization, and Olympic style.

And among the countless supporting organizations and certifications are the NSCA, ACSM, NASM, AFA, IDEA, ACE, and YMCA.

With such an abundant source of information, the would-be practitioner can be forgiven for wondering about which philosophies to accept and which organizations to join.

Whatever philosophy or organization you choose, you must understand that certain standards never change and that you should never be tempted to stray from sound concepts because they appear to be "old-fashioned."

I believe that the 14 facts, or basic principles, that follow should be carefully considered in deciding upon a strength-training protocol.

* ALL OR NONE PRINCIPLE:

A muscle fiber extends from its point of insertion to the point of origin. When a muscle fiber is stimulated to contract, the entire fiber is affected and pulls these points of attachment together. It is therefore impossible to work only the "Upper" or "Lower" portion of a muscle fiber. If not stimulated, the fiber will not contract.

* SLOW-TWITCH FIBERS:

Also referred to as Type 1 or Red Muscle Fibers. Such fibers are more fatigue resistant, as they have more mitochondria, capillaries per muscle fiber, endurance enzymes, and intramuscular triglyceride stores for aerobic energy utilization (10).

* FAST-TWITCH FIBERS:

Also referred to as Type II or White Fibers. These fibers are utilized during short-term strength and power activities. They possess more glycolytic enzyme activity, more myosin ATPase activity and more intramuscular phosphate stores for anaerobic energy utilization (10).

* SIZE PRINCIPLE:

A motor unit consists of a nerve and all the muscle fibers it innervates. If a strength stimulus is small, only a few motor units will be recruited. A greater stimulus will recruit more motor units and consequently more muscle fibers (4).

The smaller slow-twitch fibers are recruited first. As the stimulus continues and strengthens, the stronger and larger Type II fibers are recruited. However, some scientists hold that while the size principle is correct for single-plane, isolation movements, it does not apply for more complex movements (1).

Until this is proven, the size principle should always apply.

* FORCE-VELOCITY CURVE:

This relationship demonstrates that for rapid concentric contraction, the resistance/force must be low. Consequently, high resistance will allow for a much slower shortening of the muscle (2).

This does not mean a large force cannot be moved rapidly. As one continues to develop maximal strength, a greater submaximal weight can be handled more easily.

* ACTIN PROTEIN:

The thin protein filaments located with the myofibril of the muscle.

* MYOSIN PROTEIN:

The thick protein filaments located within the myofibril of the muscle. Myosin, along with the actin protein filaments, are responsible for muscle contraction.

* FORCE-LENGTH RELATIONSHIP:

In the human body, a muscle is isometrically stronger in a position slightly stretched beyond its resting length (2). This allows a greater potential for interaction between the actin and myosin filaments. The muscle will be weaker at lengths less than this position.

* FORCE-MASS ACCELERATION:

Shows the relationships between the mass of an object and the muscular force required to move it. Muscular force can be improved by one of three ways: (1) increasing the mass of an object while keeping the acceleration at a constant velocity, (2) lifting a given weight at an increasing velocity, (3) increasing the mass of an object while simultaneously increasing the velocity.

* WORK-FORCE DISTANCE:

Demonstrates that the amount of work accomplished is proportional to the muscular force utilized and the full distance this force traveled. This is why a full range of motion is always encouraged.

For example, 100 lbs. of muscular force lifted three feet will accomplish more work than 200 lbs. of force lifted 1 foot. While 200 lbs. is heavier, the amount of work accomplished was less because only a third of the distance was covered.

* POWER-WORK/TIME:

The concept of power is important because it describes the rate at which work is being accomplished. Power is increased by any of the following: (1) enhanced distance with the same force for the same or less amount of time, (2) increased muscular force over the same distance for the same or less amount of time, (3) increased muscular force over a greater distance within the same or less time frame.

The development of athletic power is one of the most debated issues with strength coaches. Following are some techniques currently used to increase athletic power: (1) raise a given amount of weight, over the same range of motion, in less time, (2) raise more weight, over the same range of motion, in the same time frame, (3) complete a volume of work (total repetitions x weights x sets) in a shorter time frame, (4) complete a greater volume of working the same time frame.

* OVERLOAD AND PROGRESSION:

The two most important principles within strength training. The individual should always attempt to better himself in each workout. This can be accomplished by increasing the amount of weight, repetitions, force, work, and/or power. This is the only way the body can adapt and increase its strength and power.

* SPECIFICITY:

This is also a controversial topic with strength coaches.

Webster's Dictionary defines specific as: "Accurate, Precise." StairMaster's Fitness Handbook defines it as: "The principle that the body adapts very specifically to the training stimuli it is required to deal with. The body will perform best at the specific speed, type of contraction, muscle-group usage, and energy-source usage it has become accustomed to in training."

The following quote from David Lamb emphasizes the need for specific training: "The athlete must repeat the appropriate movement patterns in a skillful manner many thousands of times during practice so the nervous system learns to perform the movement correctly every time throughout the entire duration of competition."

* OVERTRAINING SYMPTOMS:

It is very easy for the competitive athlete to perform too much exercise and become overstressed. Increased rest periods are needed when the following symptoms are present: sleep disturbances, irritability, fatigue, depression, anxiety, higher resting heart rate, changes in normal blood pressure, confusion, hostility, weight loss/excessive thirst, prolonged weariness, and elevated body temperature.

In conclusion, whatever strength training techniques and philosophies you chose for your athletes, these principles and facts should always apply. Always start with the basic sciences and use them as a base to develop your protocol. While research is never-ending and constantly changing, these principles will always apply.

References

1. Journal of Applied Science Research. Short Review: Rate Coding and Motor Unit Recruitment, Michael Deschenes, Vol 3, #2. 1989.

2. Basic Biomechanics, Susan Hall, Mosby-Year Book: St. Louis, MO. 1991.

3. Strength and Power: A Definition of Terms, Everett Harman, NSCA Journal, Vol. 15, #6, 1993.

4. Journal of Athletic Training. A Review of Overtraining Syndrome - Recognizing the Signs and Symptoms, Mary Black Johnson, Vol. 27, #4, 1992.

5. Sports Science Exchange. Basic Principles for Improving Sports Performance, David Lamb, Vol. 8, #2, 1995.

6. The Fitness Handbook, James Peterson and Cedric Bryant, Wellness Bookshelf, 1995.

7. Exercise Physiology; Theory and Application to Fitness and Performance, Scott Powers and Edward Howley, Wm. C. Brown Pub., Dubuque, IA, 1990.

8. Webster's Seventh New Collegiate Dictionary, G. & C. Merriam Co., 1963.

9. Strength Fitness, Physiological Principles and Training Techniques, Wayne Westcott, Wm. C. Brown Pub., Dubuque, IA. 1989.

10. YMCA Strength Training Manual, Music Physiology and Biomechanics, Human Kinetics, Indianapolis, IN 1994.