After reading the book "Born To Run" by Christopher McDougall I was intrigued about barefoot running. In the book Christopher talks about this in length and it really struck a chord with me. I had bought my first pair of Altra zero drop running shoes which are as close to barefoot as you can get, about a year earlier before I read the book and found that my feet got very strong. It makes perfect sense to me that feet have not changed for thousands of years so why not run into something as close to barefoot without all that corrective footwear accessories of modern running shoes. I am injured less now and have run a few trail ultra marathons. I read about barefoot running in another book by Michael Sander was that there is a resonance frequency that the earth emits is the same frequency as our brain emits. The frequency is 8 Hz. This is also our natural circadian rhythm. When we run barefoot we are in sync with the frequency of the earth. I feel this when I run on the trails and feel connected to the earth. If you run with running shoes which have corrective footwear accessories the distance of your feet from the earth is greater than barefoot shoes so your body is not in sync with the earth. The frequency is called the Schumann resonances.