Although this may sound easy, when properly performed it is incredibly intense and capable of producing a very deep level of muscular inroad.
A disadvantage of timed static contraction is that unless it is performed on equipment with a force gauge, there is no objective or accurate means of measuring exercise performance or progress. Since the subject is contracting against a fixed object rather than resisting the pull of gravity on a barbell or the back pressure of a machine’s movement arm there is no way to quantify resistance.
Static Holds
During a static hold a barbell or the movement arm of a machine is transferred from the instructor or training partner to the subject in either the fully contracted position or end-point of a simple exercise, or in the mid-range of a compound movement. The subject then contracts against the resistance, attempting to hold it motionless as long as possible. After the muscles are inroaded to the point where it is impossible to prevent the downward movement of the resistance, the subject continues to contract against the resistance, performing the negative as slowly as possible.
Most subjects require approximately 20% more resistance for static hold than they would use for a set of dynamic exercise of similar duration. This will vary somewhat between individuals and muscle groups, and when using barbells or equipment with incorrect resistance curves the increase in resistance necessary depends on the position or joint angle at which the exercise is performed.
Mike Mentzer’s protocol for a static hold is as follows:
Static holds require considerably more caution than timed static contraction due to the requirement for a relatively high amount of resistance and the need for inter or intrapersonal transfer of resistance in many exercises. static hold may not be appropriate for some subjects who can not tolerate dynamic exercise due to injuries or joint deformities, in which case timed static contraction should be used.
The only advantage of static holds over timed static contraction is that it allows for measurement of exercise performance and progress in terms of resistance x set duration. If a subject performs a static hold for the prescribed duration before muscular failure occurs, the resistance should be increased the following workout.
Interpersonal Resistance Transfer
It is extremely important that interpersonal transfer of resistance be performed properly. When handing the bar or movement arm to the subject it is important not to suddenly let go, abruptly loading the subject, as this may cause injury. When the bar or movement arm is in the desired position and the subject indicates that he is ready the instructor or training partner should inform the subject that he is going to begin to transfer the resistance. While the subject holds the bar or movement arm motionless, the training partner should very gradually reduce the amount of force he is applying as the subject gradually increases the amount of force he is applying until the subject is supporting all of the load. At the point where the training partner has completely transferred the weight to the subject, he should indicate that he has done so, and begin timing the set.
Exercises requiring interpersonal transfer should be performed using machines with fused rather than independent movement arms, and barbells rather than dumbbells, as this allows both the subject and the training partner better control over the weight during the transfer and is therefore much safer.
Intrapersonal Resistance Transfer
During intrapersonal transfer, rather than the transfer of resistance being between the instructor or training partner and the subject, the subject is transferring the resistance from one of his muscle groups to another. For example, when performing static or negative only chins on the Nautilus Multi Exercise, the subject would set the machine’s carriage so that while standing on the top step the chinning bar is level with the top of his chest. He would then gradually raise his feet off of the step transferring his bodyweight from his legs to his arms and torso. This can also be performed with a regular chinning bar using a stepladder or tall chair.
Position Specific vs. Full Range Strength Increases
Isometric exercises should be performed near the middle of the range of motion for most exercises where the overlap of myofibrils allows for optimal force production and greater tension in the targeted muscles. Positions at or near the end point may be more effective in some exercises as long as active insufficiency of the targeted muscles is avoided. Isometrics should not be performed at or near the end point of compound pushing exercises where little meaningful resistance is encountered by the target muscles while the joints may be subject to large compressive forces due to the lever advantage.
Arthur Jones, the founder of Nautilus, has often stated that the only position in which one is capable of contracting and thus stimulating all of the fibers in a particular muscle is the position of full muscular contraction. This is incorrect. While positions or ranges of motion involving a lesser degree of shortening may not be as ideal, motor unit recruitment (contraction) and thus the possibility of stimulation, does not require moving into the “fully-contracted” position. Motor unit recruitment depends on the force requirements of the exercise. If the force requirements are high enough all motor units will be recruited regardless of where in the ROM the exercise is performed.
Based on this it would appear that isometric exercise protocols such as timed static contraction and static hold should result in full-range rather than position or range specific strength increases. However, the fact that many exercises involve multiple muscles or groups of muscles whose relative involvement may vary considerably over the full ROM complicates the issue somewhat.
Compound (Multi-Joint or Linear) Movements
Isometric exercise protocols may not produce full range strength gains in some compound movements. Unlike many simple or single joint exercises, during compound exercises significantly more muscles are involved and the relative involvement of those muscles changes continuously from position to position throughout the range of movement. Depending on the degree of change in muscular involvement from position to position, isometric exercise in some positions of a compound movement may provide inadequate loading and stimulation for muscles that are not involved to some minimal necessary degree at that position, but may be involved to a greater degree in other portions of the ROM. As a result, there would be a disproportionately low strength increase in those parts of the ROM.
For example, during the front grip pull down, the chest is involved in shoulder extension during the first 30 to 45 degrees of movement. If a person performs timed static contraction or static hold on the front grip pull down in a position past that portion of the ROM involving the chest, the resulting strength increases will not be proportional over the full range of the exercise. They will be lower over the ROM involving the chest.
Realize that in such a situation although strength increases may not be proportional over the full ROM, they would not be limited to the specific position trained either.
In exercises where this is a problem, one should either perform the exercise at a position in which all of the muscular structures involved in the dynamic version of the exercise are meaningfully loaded or address the inadequately loaded muscles with a different exercise.
Weight vs. Resistance
During compound pushing movements such as squats, chest press and overhead press, none of the muscles involved in the exercise are meaningfully loaded near the position of full extension due to changes in leverage. In positions at or near full extension the bones support the majority of the load and the muscles encounter significantly less resistance. This lever advantage is the reason a person can perform partial repetitions in these exercises over the portion of the ROM near extension with much more weight than they can use to perform the exercise over the full ROM.
Weight and resistance are not the same thing. Weight is a scalar quantity, a measure of an object’s mass. Resistance is a vector quantity, a type of force, which in the case of exercise is a product of weight and leverage. Depending on leverage, one can have a tremendous amount of weight with very little resistance in some positions, as in the above compound exercises, or a tremendous amount of resistance with very little weight. It is the resistance the muscle encounters during exercise that is important.
When used with compound pushing movements static holds should be performed in the position where the target muscles encounter the greatest resistance, not where the most weight can be handled. This position will vary depending on the equipment used. An exception to this would be cases where these techniques are being used to work around an injury or physical condition which prevents dynamic, full range exercise, in which case the position depends upon the subjects physical limitations.
Strength Testing
Comparisons of the relative effectiveness of different exercise protocols using a dynamic test to measure changes in strength are grossly inaccurate due to several factors. These include the effects of skill, apparatus friction, body and apparatus torque variation, momentum and problems with positional reference, etc. Performing static testing solves most of these problems and minimizes others. Static testing involves no significant friction, no momentum, no torque variation, and minimizes the influence of skill from dynamic training protocols. MedX medical machines also make it possible to accurately counterbalance body torque and factor for torque produced by stored energy during isometric testing.
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