The stimulation cycles are for people who are already accustomed to electrostimulation and want to perform several training cycles.
The cycle logic refers to the workload performed by electrostimulation. Just like a normal workout, one has to to start with an amount of effort then increase it over the course of the cycles. Thus, it is recommended starting with the 1st cycle and going on to the next level when the cycle is finished, normally after 4 to 6 weeks of stimulation based on 3 sessions per week.
It is also important to have reached significant stimulation intensities in sessions before going on to another cycle. At the end of a cycle you can either start a new cycle or do maintenance training based on one session per week.