دورة التنفس

Breath cycle is the repeatable sequence of breath phases that usually include inhalation, exhalation, and might include air retention and air sustain, depending on a "ratio of breath cycle", and thus a training type chosen. The length of a breath cycle, divided by time (in minutes), is known as "breaths per minute" value; it defines the training complexity of your breathing gymnastics session.

Where the breath cycle can be seen in Prana Breath app

It appears in Training tab and in Control tab, expressed visually as the training chart.
Also it can be seen as a line graph in Dynamic tab.

How the breath cycle can be set

Use the parameters you can find in Control tab and in Dynamic tab for setting the ratio of breath cycle and training duration.