Thank you for your question!
That question has already been answered here:
If you do a search in the “search articles with keywords” in the main page and type: “spin discus” or other words related such as “self realization,” you will find more articles about it.
In a nutshell, any time that your mind is stuck in a thought which may cause sorrow, we need to move our thoughts, to “get out,” that is basically what spinning the discuss does. You can experience this “drill” while cooking your meals, your yoga is connected while thoughts are moving due to your attention in cooking while connected. That is the idea. “Spinning the discus” is called physical remembrance. If you are thinking all the time, you can “choose” what to think of, that is “spinning the discus” to cut the devil’s head… 🙂