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- Introduction
- The all or nothing theory of muscle activation
- The protective joint sensors
- Relationship between strength training and muscle activation
- Summary
Moderation in all things in life has been the advice of many a parent over the years. It is almost a certainty that you have been exposed to this as you grew up. In most cases the saying has merit but not when it comes to getting stronger. When it comes to getting stronger, throw moderation* out the window. Your muscles don’t act in a moderate manner, so why should you?
Now just because I said to throw moderation out the window I did not say to throw caution out with it. Use your head while you train or suffer the consequences of your imprudent actions.
* Moderation is a relevant term in this context. Don’t be stupid with your weight training or you will get hurt.
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The all or nothing theory of muscle activation
Before we move on let’s review the all or nothing theory of muscle activation. This states that when a specific set of muscle fibres within a motor unit reaches its threshold of activation either all of the fibres in that unit fire or none do. There is no such thing as a ‘maybe firing’. This is similar to a woman being pregnant; she either is, or is not - there is no middle ground.
Once this concept is understood it’s time to consider what happens when the motor units are all firing to move the weight. Without something to protect the body from excessive loads it would be possible to damage the integrity of the joints.
The body has built-in feedback loops to help protect it from harm. The most significant are the Golgi tendons and the muscle spindles. Both of which are ultra protective of the joints. Resetting the levels of activation for these protective mechanisms may be the key to greater lifting achievements.
The muscle spindles are located, actually intertwined within the muscles themselves and can sense when the muscles are being stretched (lengthened) rapidly. When this happens a signal is sent to the spinal cord which then tells the motor neurons to tighten up, to ‘reflexively contract’. This helps prevent the muscle from being over stretched to the point of injury. However this only works during rapid lengthening of the fibres. A fibre that is slowly stretched doesn’t receive the signal to contract and is thereby susceptible to damage. The opposite reaction to the muscle spindle comes from its counterpart in the joint protective association; the Golgi Tendon.
The Golgi tendon, located at the junction of the tendon and muscle fibres intersection, senses when there is high tension on the tendon. When this sensation of excess is noted a signal is immediately sent to the spinal cord to inhibit further contraction of the muscles attached to the tendon. Additionally another signal is sent to the antagonist muscles telling them to contract. Here in lies the problem of moderation.
It may be that the Golgi tendon response is set too low. Re-adjusting this could be the answer to greater strength outputs. But this is dangerous territory as injury is just around the corner if the limits are pushed to far upward and the joint is damaged by a disproportionate, in relation to training experience, weight. The question before us now is how can we make these two seemingly incompatible protective devices work for us and not against us, in our training.
Relationship between strength training and muscle activation
Since we know that the smallest and lowest threshold muscle motor units activate first we have to figure out a way to bypass this process. Secondly we have to figure out how to reset the Golgi Tendon response so more weight can be lifted. Is this a possibility? Yes to a certain extent it is. The answer is through proper training practices.
Periodisation of the training load intensity, volume and rest to work ratios will allow this training effect to take place. Remember only those motor units that are recruited to lift the weight are trained. If they aren’t activated they won’t be exposed to the stress of the training. Recruitment of the type two fibres is the goal for the strength athlete.
The order of recruitment is thought to be genetically fixed however this may be altered by using heavy weight and/or placing a high power demand on the muscles. Variations in the recruitment order and small changes in fibre type composition are also thought to be possible through a well designed training program.
A competent strength coach will be able to design strength program for you that meets the needs of the prior discussion. If you are interested and motivated enough to follow through with the plan you will reap the benefits.
Resistance training (or strength training) can be a valuable asset in your sports activity program. These strength cycles will generate changes in the physiological makeup of the body if they are properly planned. Moderation is not what will elicit these changes. Only maximal training effort will lead to maximal change in the muscle fibre recruitment and composition. The plan should involve periodisation principles for the greatest effect and outcome.
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Article credit:
Article by Danny M. O’Dell, MA. CSCS*D,
Explosivelyfit Strength Training
Website: Explosivelyfit.com
references
- Brown, L. E. et al. Strength Training, 2007
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