- I have a student who asked me why you advise not to wear anything circular during a Yin practice. This is something I have never heard and cannot answer. Can you shed some light on it?
First, the genesis of this question: in my book, The Complete Guide to Yin Yoga, I stated before doing your yoga practice "Also remove any metallic circles you have on--things like rings, bracelets, and body piercings can interfere with the flow of energy." Why do I suggest this? I have no definitive proof that metal circles will interfere with your energy (chi flow), but it is a well known fact in science that metal circles can interfere with or retard the flow of electromagnetic fields. This video gives a vivid demonstration of this effect. This is the basic principle behind how electric motors and generators work. If we move a magnet through a coil of metal wires, the magnet will induce an electric current in the wire. Similarly, when electricity flows in a coil of wire, it generates a magnetic field. The magnetic field created in a metal coil will in turn produce a resistance to the flow of electricity, also called "Back EMF" for the technically minded. (Look up Lenz's Law for more cool videos on this effect.)
One possible form of chi energy is bioelectromagnetic energy. We create electromagnetic fields in our body. We can measure these fields with instruments like an ECG, EEG or an MRI. During our yoga practice, one intention is to stimulate these flows of energy. Since we know that metal circles (such as rings or bracelets) can change or resist such fields, it is interesting to experiment in your yoga practice and try your practice with and then without metal circles. See for yourself if it makes a difference.
Some teachers have said that the worst metal circles are belly button rings. I have had several students tell me about their experiences with belly button rings: in one case, a student had been wearing such a ring in her navel for quite a while. She had always had problems with finding a stable position in her headstand postures, until an acupuncturist asked her about her ring. He knew she practiced yoga and asked how her headstand was. She said "not so great." He suggested that she remove her belly button ring next time. She did and found that for the first time she was rock solid in the pose. This is not proof that metal circles will affect your energy; it is only one anecdote. But several other students have reported similar findings.
Try it for yourself. Check it out and see if it makes a noticeable difference in your practice and how you sense the flow of energy within.