"it will remove the internal imbalances brought on by the one-sided nature of martial arts training"This quote is referring to the physical part of martial arts training. So to avoid conflict or point fingers I am not going to tell you where the line comes from because that is not the point of this post. The point of the post is, however, to point out that if you are training in the martial arts and your training regime leads to this type of result, things being anatomically one-sided. You are doing it wrong!
Several of my instructors have taught me repeatedly about the need for balanced training across the Sagittal plane of the body. (This is the plane that divides us in half right down the middle.)
If we practice a punch from the left side, we in turn practice the same punch from the right side as well. If there is an imbalance on one side or the other we would also increase the number of repetitions on the weak side to get it "caught up". For a weak left side Gyaku Zuki or Reverse Punch for example, we perform 10 punches on the right during training and then 20 on the left side till we feel the imbalance is reduced. internal feedback from the the coordination or power generation issues we were experiencing.
Imbalances in the body are normally not brought on by a good training program. There are many texts that discuss the positive effects of a good program on the body. When recruiting soldiers in Japan around the time of World War II the Japanese government noted the impressive symmetry of the Karateka they recruited from Okinawa. A symmetry that is not entirely natural in most people since we have a dominate side and favor it in daily life.
To fix this in training, a beginner should be able to rely on their instructor to point out imbalanced in the body during training. A good instructor will help their student balance those issues throughout training. Later on a more advanced student should be able to feel the difference during training. That may sound like hocus-pocus but if you have ever been involved in athletics of any kind you know what I am referring to here. It is a kind of internal feedback loop. You just know when something feels wrong. Even for an advanced student it is a good idea to occasionally seek feedback from an instructor or fellow student.
In the end, if this statement is even remotely true and you are training in a program that does have you training to imbalance, change it up. It is time to reorganize. I am a firm believer in cross-training but it should be used to strength a good program. The difference put simply is this:
Good program is 1. Lets say that cross training is also a 1. That means that 1+1=2 and both programs are moving us forward toward being stronger overall.
Bad martial arts program is a -1 and then cross training is a 1 still. -1+1=0. We do not make much progress in a program that requires we add training to fix problems in other parts of our training.
For anyone who reads this, I don't want to know who does this so do not post names please but how common is this problem? Please feel free to add a comment if you have seen this or if this is a marketing gimmick to sell cross training programs.