Voice teachers often try to placate the frustration of their students by telling them it is normal to feel as if they take a step forward and two backwards. Indeed they are correct in terms of the feeling. But would it not be more beneficial if they also knew that along with that depressing illusion was also the more positive fact that they were actually moving continually forward? Indeed that is the case. The illusion of "steps backward" is indeed merely an illusion. Those of us who have had experiences with sports do not find the concept foreign, although the passion of singing often renders us forgetful of parallel experiences that indeed could have been helpful.
In sports medicine, we learn that athletes train often to transform fast twitch (generate quick contractions but tire quickly) muscular motor units to slow twitch (better for endurance). Slow twitch units recover faster and contribute to stamina. As the muscles are in the process of being transformed, it is not unusual that an athlete will experience great stamina on a given week and then suddenly less on the following week. It is because the stamina of a given muscle group depends on many motor units that do not necessary grow in strength in the same amount of time. When all the units are strengthened, then the muscle as a whole will be able to recover faster and lasting stamina will have been achieved. (Skeletal muscles have both slow and fast twitch fibers recruited depending on the nature of the work at hand).
The recruitment of muscular motor units is specific for each pitch. The specific balance between the CT and TA (and by extension the IA) for a given pitch is what yields a pitch of a desired quality. If the production of that given pitch had been out of proper balance (such that would yield peak phonation efficiency), then the process of achieving proper balance would require a reorganization of the laryngeal musculature (not only those primary three). Such reorganization would require a different recruitment strategy of the motor units, which depending on their strength could cause the singer to feel considerably weak at the onset of the new muscular organization. In other words, what is correct would feel strange, weak and more difficult for a period of time during the transition.
It is a common experience to see the singer worry when they first begin a muscular rebalancing or a little impatient at the end of the process. One of my coloraturas sang an Ab6 at her last lesson and with the joy that came with it was also a little frustration that the extreme top notes are not yet at the strength level of her newly strong middle range. She is peaceful at this stage because she had gone through the process and saw her gradual improvement. She now knows that the illusion of steps backward is just an inertial period that will give in to a new level of strength. The trick is to get a new singer to understand this.
Even explaining the process here is of little comfort to the singer who has been struggling for years. When singers have been struggling without the desired results for a long time, it is difficult to gain their trust relative to a time-dependent process. The simple goal of this quick post is to reassure the singer that s/he will experience weakness even as s/he gets stronger vocally and to encourage him/her to persevere through the periods of weakness to eventually accomplish lasting strength and stamina.