There is no necessary connection between making fitness plan and measuring muscle circumference. It's just that if you measure your physical indicators every once in a while, it will help to enhance your confidence and adjust your plans for the next stage.
The bodybuilding plan, in fact, we have all mystified this. In my opinion, it is completely unnecessary. As long as it suits your own plan, there is no perfect fitness plan-,-#
That's it in short. I hope it helps you.