We constantly hear about free radicals, and how we need anti-oxidants to combat them. Free radicals are molecules, technically ions, which have a positive charge. They need an electron to be neutralized. Our red blood cells will sacrifice an electron in order to neutralize free radicals, but the cost is that when the normal negative charge on red blood cells is absent, they will no longer repel each other and they will clump together. This clumping prevents them from passing through capillaries freely and circulation is compromised. By electrically connecting our bodies to earth, which is a source of limitless electrons, we restore the proper electrical balance to our bodies.
Personally, I have been sleeping grounded, using a very simple system of a 3 foot long piece of bare wire connected to the ground of an electrical outlet and laid across the top of the bottom sheet of my bed, for about a year now. It has eliminated the occasional stiffness in my lower back in the morning.
Hopefully this introduction will encourage you to learn more at the Earthing Institute website: