The Humon Hex is the first clinically validated wearable to use optical sensors to non-invasively monitor the oxygen levels in the muscle. Unlike wrist worn wearables of the past, the Humon Hex is designed to be worn directly on the working muscle to measure oxygen saturation. The Hex provides personalized training insights that help athletes improve their performance. The athlete is guided by the Hex through the display of colored training zones that can be used to adjust pace. These insights are provided on a phone, watch, or bike computer in real time.