The first post of the series is most likely going to be the hardest to grasp, but do not get intimidated by it being about the science side of strength maintenance. In reality, it is equally as important to understand WHY something works as it is to know THAT is works. Better understanding typically means better results. To best understand how strength is maintained, it is first important to understand the basics behind how strength in built.
As many of us know, we get strong from lifting heavy things. Our bodies respond through our muscles and our nervous system as a result of lifting heavy objects. Weight lifting involves, to varying degrees, a breakdown of muscle tissue. This occurs in response to the stress placed on them from the load being lifted. The breakdown of muscle tissue creates a stimulus telling the body to make more muscle, so that less is broken down next time.
MOTOR UNIT RECRUITMENT
Our nervous system responds to the picking up of heavy objects by increasing motor unit recruitment, or “waking up” the muscle. Motor units are nerves that are responsible for turning on portions of a muscle, and each muscle will have multiple motor units. What I mean by “waking up” is that, for the most part, only a percentage of a muscle is active during any given movement and increasing the motor unit recruitment, “waking up,” will increase the percentage that is active. For instance, our imaginary friend, who we will call John, may only have 75% of his quadriceps firing during a squat. If John continues to squat over a period of a few months, John can increase that percentage to 85%. The resultant increase in percentage of the muscle being used is attributed to increased motor unit recruitment, or a “waking up” of the muscle.
Another response in our nervous system is increasing muscle fiber synchronicity. Muscle fiber synchronicity refers to the ability of the fibers in a muscle to work together. If synchronicity is low, the fibers will fire in an unorganized fashion, resulting in a loss of strength. If muscle fibers become more synchronous and fire all together at the same time, they become much stronger. Synchronicity works in the same fashion as a team. Good teams work together to achieve a goal, and the fibers in strong muscles work together to produce a strong movement.
Rate Coding is the third response that occurs in our nervous system. Rate coding is essentially the ability of your muscles to work smoothly. Not all of a muscle needs to be active at all times, if that were the case we would move in jerky, robotic movements, and rate coding allows our body pick and choose what is active. Rate coding is the hardest to understand (and explain) of all the neurological factors, so I’m going to leave it at that. If you are curious and want to read more of it, THIS is a good article to read.
When engaging in strength specific training, it is a combination of those factors that creates a stimulus acting on the body to make us stronger. They are the main reasons why you are able to lift a heavy object one month, and a heavier object the next. FYI: Nervous system factors provide a more potent stimulus for increasing strength than muscular factors, and do so without the side effect of being sore the next day.
I had mentioned earlier that strength is not something that stays forever. Once strength is no longer being trained, it will start to decrease. This decrease is not immediate. Gained strength will last for a certain amount of time even after cessation of training. The time period that it lasts is called a training residual. For strength, the training residual is typically around 4 weeks, but that can vary. The length of the residual is dependent on the amount of time spent training the variable. Gained strength that was trained for two months will last much longer than gained strength that was trained for 2 weeks.
Training residuals can also be lengthened through maintenance work of the variable. Maintenance work is the training of the variable in a high intensity, low volume setting. Performing maintenance work is important because it produces the neurological stimulus in the body, with minimal side effects.
Bringing it all together, strength is gained through the training of the muscles and the nervous system. Strength is maintained through maintenance work, which is done to specifically target the nervous system. That’s it for this portion of the series. Next time I will discuss HOW strength maintenance should be implemented to provide results without affecting performance.