Think of Counting as Cadence
When going through an exercise of any sort, such as Kata, Kumites, physical training or even stretching, a solid count goes a long way with helping inspire a class to give it their all. But it is not really the “count” that helps achieve this goal.
When a seasoned instructor is standing up in front of a class and counts a class through an exercise in Japanese, he or she is accomplishing two different (albeit important) goals. The expression “better caught than taught” comes to mind. It is not necessary to sit with a class and teach them everything. A good instructor can have things repeat in a way that allows the student(s) to learn from his or her demonstration. One of those things is often counting in Japanese.
For the purpose of the exercise, the Japanese count is not necessary for a nervous instructor. For the seasoned instructor, however, there is no reason why it shouldn’t be done. The point of the count is to create a cadence. That can be done by chanting in a rhythmic fashion. The purpose of using numbers helps establish a goal. For instance, getting a class to execute ten pushups might be easier if you count to ten, but that is done as easily in English as it is in Japanese.
A good cadence, with proper voice inflection, does a lot to encourage a group to work harder. This is nothing new. The rhythm of a good cadence has been used for centuries for duties such as rowing teams on merchant ships and drums for soldiers marching into battle. It is still used in the modern day with marching bands, soldiers in training and sporting events. I believe the whole idea behind the iconic Queen song We Will Rock You is a cadence for a crowd to follow.
A good cadence is catchy and addictive, therefore helpful in motivation. Once an instructor is comfortable with developing a cadence with a class, many useful extras an easily be added. For instance, an instructor can swap out using English as a count for Japanese - for the purpose of educating the class on how to count in Japanese. A talented instructor will alternate back and forth between the languages to help the students understand even more.
Likewise, more detailed corrections can be inserted during the cadence. Such as One, Two, Three, Four! can be replaced with Let’s, Keep, Our backs, Straight! For a seasoned instructor, this allows minute corrections to be made without stopping the whole class to make a point, and all of this being done while motivating a class to keep up with their exercise.