In order to regulate your own training, it is very important to understand how the body reacts to exercise. As mentioned in the previous chapters, strength training is a stimulus. Your body is an organism which undergoes adaptive changes in order to be better prepared for the same stress in the future. As mentioned previously, the body is reluctant to invest resources into an adaptation unless it is percieved as a direct threat to survival. Provided that the intensity of effort is high, strength training will fool the body into believing that there is a direct threat to survival, and this will force an adaptive change - in this case, increased strength and muscle size.
Imagine that your strength, or functional ability, is the ground. It represents your current level of strength. When you go through a strength training session, you are taking a shovel and digging a hole - an inroad - into your functional ability. After training, you are left with a big hole in the ground. If the intensity was not sufficient, you would barely have broken ground. If you trained with the proper intensity, but used too many exercises or performed too many negatives, breakdowns, or other post-fatigue repetitions, you would be halfway to China. With a high intensity, and just the right amount of volume, there will be a substantial, but not overly deep, hole in the ground.
Now you're left with a hole in your functional ability. Your strength levels are reduced dramatically. Your body has recognized this and has begun to compensate for the inroad and bring you back to normal once again. Your body invests its resources into filling up the hole with more dirt. The hole gradually fills up with dirt, and after a few days you are back where you started if you had the right amount of intensity and volume. If the inroad is too deep, though, the body will not be able to fill up the hole all the way, and you will be left with a decreased functional ability - what we call overtraining.
Your strength levels have now returned to normal. The hole is filled up to its previous capacity. But that's not enough. You are training to increase strength, not to maintain it, right? Your body will return to its previous levels of strength, and then invest a little bit more in reserve to be better prepared. So you have hole filled with dirt, and you throw a little more dirt on top. The next session, you dig an inroad just as deep, but this time, you are digging into your previous functional ability PLUS that extra bit of strength. The hole gets filled again, and then more dirt is thrown on top. Little by little, what once was the ground has turned into a mountain, and this represents your strength and muscular size.
It is very important to remember that you need to allow time for recovery. The process has been clearly illustrated in the analogy, and it is quite simple to see that if you do not allow enough time for the body to grow stronger - to build the mountain - then there can literally be no progress. The time it takes for the body to recover varies from person to person, but just keep this analogy in mind when you are determining how often to train. Scheduling sessions more often does not mean faster results; the process must be allowed to run its course before another productive session occurs.
Thanks to Mike Mentzer and Dr. Doug McGuff for the ideas presented in this article.
