What you are looking at is two different measurements of protein synthesis in the human body. “Whole body protein synthesis” is a measurement of the protein synthesis happening in your entire body. This includes things like your liver, heart, lungs, brain GI Track and your muscles. This measurement does not tell you WHICH part of your body the protein synthesis is happening in, just that it is happening. “Muscle protein synthesis” is specifically measuring the amount of protein synthesis that is happening IN your skeletal muscle.