> The Ancient Greeks knew what it took to grow stronger, but their ideas about the body's physiology were a little mystical. They believed in harnessing an ethereal substance called pneuma, a bit like the Chinese chi. This involved suspending and holding the breath, tensing all the muscles of the breast and relaxing the stomach and diaphragm, therefore "pushing the excrements" down, according to Christopoulous.
This techinique along with muscular programming is really powerful. It makes possible running up a slope at full speed while making footsteps completely silent, for a long time, without feeling tired or sweating, and then recover your normal breath instantly.