The science behind the Muscle Oxygen Monitor is simple once you understand it. The device sends a special light (near-infrared) into your muscle. Some of that light gets absorbed by oxygen-rich blood, and some by oxygen-poor blood. The sensor measures how much light is reflected back, and then it calculates how much oxygen your muscle is using. It’s not just for professional athletes. Anyone who exercises can benefit. Even physical therapists use it to help injured people recover.