We always find some form of cyclicity present in the nature, both internally and externally. From sleep cycles, breathing rhythms to revolving Earth in the Solar system, and planets circling around the sun. So, any practice for inner growth should also incorporate cyclicity for smooth operation. We human beings have a high propensity for stimulation most of the time, but we rarely know the method of relaxation. Therefore, Cyclic meditation is an art that provides us the adequate knowledge of relaxation technique. Practice of transcendental (Om) meditation for 20 minutes and Cyclic meditation for 25 minutes can give much more rest than 6 hours of sound sleep.

Yoga mats are recommended for these sits, though not mandatory.

Also see https://www.healthandyoga.com/html/sutras/pt_yogasutras63.aspx