by Yuri Verkhoshanshy
Edited by Jim O’Malley
Editor's note : Professor Verkhoshansky is widely
recognized as the world's foremost authority on
speed-strength training.
Introduction
The author conducted a study regarding the
composition and structure of the capacities that
generate explosive movements, depending on the
following variables :
*the type of sport
*the participant's age, sex, and length of sporting
career
*the type of muscle contraction, the type of resistance
and the level of resistance
*the composition and number of body components
actively involved in the performance of the exercise
I took into account that dynamic and isometric
contractions do not exhaust all of the varieties that are
possible in an approach to conditioning training - in
particular the so called "combined regimen" in which
the contraction is preceded by mechanical stretching
of the muscles, a widely spread system in the training
of many sports. When a "combined regimen" is
operative, the elastic potential of mechanical muscle
stretching provides an extra source of energy which
enhances the subsequent muscular contraction.
A muscles ability to switch rapidly from a yielding
(eccentric) contraction to an overcoming (concentric)
contraction by using elastic potential (accumulated
during stretching) to increase the muscular contraction
is commonly known as the neuromuscular systems
"reactive capability".
Finally, the speed-strength characteristics in
controlled tasks involving overcoming (concentric) and
combined (eccentric-concentric) muscle contractions
appear to be closely interrelated. the overcoming
(concentric) contraction is a sufficiently informative
indicator of the capacity of the neuromuscular system
to generate explosive force.
Explosive Force Capabilities
The capacities that influence explosive force
applications include :
* the maximal isometric muscle strength, as
determined by isometric tension with no time limit
* the maximal muscle strength, as displayed during
explosive efforts in either isometric or dynamic
performance. In the case of dynamic work, one should
consider the level of resistance (which affects the
specific strength displayed) and distinguish between
muscular strength exerted against light, medium, and
heavy resistance.
* explosive muscular strength, as an indicator of the
capacity to rapidly generate a maximal effort during an
isometric contraction
* explosive maximal strength as an indicator of the
capacity to rapidly generate a maximal effort during a
dynamic contraction
* starting muscular strength, as an indicator of the
speed at which force is generated at the start of a
muscular contraction. It applies to both isometric and
dynamic contractions.
* accelerating muscular strength, as an indicator of the
speed with which force is developed during the initial
motion of a movable object.
This group of component capacities appears in
tasks involving explosive muscular force,
independent of an athlete's specific sport, age,
training age, and the type of muscular contraction. The
capacities are also independent of the level of
resistance, the functional specialization of individual
muscles and the composition and number of body
segments involved in an exercise.
Predominant Factors
The predominant role of one factor or another in
producing explosive force depends on the level of
resistance to be overcome in a particular exercise. In
case of a light resistance, or during the initial speed of
a movable mass, the absolute contraction speed and
the starting muscular strength are of primary
importance.
As resistance increases, the explosive, dynamic,
and accelerating muscular strength becomes more
important. On the other hand, maximal isometric and
explosive isometric muscular strength play a major
role in the so called "starting movements" that are
executed against heavy resistance.
The characteristics of the general ability to generate
explosive force in dynamically or isometrically working
muscles are, as a rule, the first factors involved in
speed-strength development exercises. However, in
regard to the factorial analysis of speed-strength
characteristics involved in ankle extension, it is the
starting muscular strength that becomes the number
one factor. This is the possible result of the ankles
specific role in sporting activities because a powerful
explosive effort is required of the ankle and foot in
virtually all sports.
The limited range of movement in the ankle joint,
which results from the functional specialization of the
respective muscle groups, demands the development
of starting strength in the muscle groups and the
ability to generate instantly effective force in a limited
range of movement. Starting muscular strength is
evaluated in isometric and dynamic performances.
However, it must be kept in mind the isometric starting
strength is a different factor from dynamic starting
strength.
According to Zatsiorsky and Verkhoshansky the
capacity to generate maximal force in isometric and
dynamic performances is generated by different
neuromuscular mechanisms. The mechanisms are
relatively independent of each other in their functional
display and development.
In dynamic contractions performed using free
weights, the muscle contracts isometrically before the
movement starts. As soon as the muscular force
equals the amount of resistance and the movement
begins, the muscle begins to contract dynamically.
Resistance Levels
Research data in the study of the composition and
structure to generate explosive strength revealed, as
expected, that the role of strength capacities when
using explosive force depends on the amount of
resistance to overcome. There is a link between the
resistance and the capacity to rapidly generate
movement against resistance. Consequently, strength
increases as the amount of resistance grows. The
maximal factorial weights of the speed characteristics
corresponds to the optimal levels of resistance.
Strength capacities can be differentiated within the
range of resistances. This fact leads to the
classification of power zones in the manifestation of
explosive capacities and allows us to differentiate
muscular force in correlation with the power zones. As
the resistance increases, there are increases in
performance, influenced by other factors, such as the
athlete's training age, body size, strength potential and
explosive and accelerating muscular strength.
While the factorial composition of speed-strength
characteristics for high performance and elite athletes
appeared to be quite clear, the same cannot be said
fro athletes in lower performance categories. Our
studies indicated imbalances in the composition and
structure of the capacities that generate explosive
force in the first stages of systematic training. This
occurs because of an uneven development of specific
capacities, the absence of a clear cut training system,
poor developmental sequences, and so on.
It is during the advanced stages of proficiency, when
the content of training becomes clear cut and specific,
that the composition and structure of the capacities
responsible for generating explosive force become
clearly distinguished. Consequently, it is important to
emphasize specific physical development as soon as
an athlete has finished the all-around general
developmental stage.
Effective Improvement
Our study also revealed that the capacities
discussed above are not of equal value in generating
explosive force. Depending on the requisites of
accomplishing a given motor performance task, one
capacity or another assumes the primary role and
therefore contains the primary potential for
improvement.
In an integrated motor performance the individual
capacities, which produce their neuromuscular
mechanisms relatively independently, interact in an
orderly manner to accomplish the common task. At the
same time, they preserve their individuality and
readiness to enter into any functional combination that
may be required under the changing conditions of the
performed activity.
It is interesting to note that our research results
failed to corroborate the frequently expressed
supposition that the ability to generate explosive
efforts is a synthesis. That is , a product of
qualitatively blending diverse capacities, such as
speed and strength, which were developed separately.
Only a regimen that virtually duplicates the speedstrength
primary requirements of an event can provide
effective improvement. Most importantly, it should be
kept in mind that the necessary functional interaction
between the specific neuromuscular mechanisms
required in a specific task are decisive. No other
regimes or combination of regimes are an effective
substitute.
