GLOSSARY

Computed Tomography (CT) uses X-rays to create cross-sectional images that can quantify specified tissues. Radiation exposure and clinical justification are relevant, and it is not a routine nutrition-tracking requirement for every athlete.

Imaging methods answer different anatomical questions. MRI can quantify tissue volumes without ionizing radiation, CT uses X-rays and provides detailed images, and ultrasound assesses local tissue interfaces and thickness with operator-dependent procedures. A local muscle thickness is not automatically whole-body muscle mass. Standardize landmarks, positioning and analysis boundaries for repeat testing. Choice of method should follow the actual question, practical constraints and clinical indication rather than assuming that a technologically complex image is always necessary for sports-nutrition decisions.

Body-composition models divide the body into components according to a defined level. A two-component model often separates fat mass from fat-free mass. Adding measured water or mineral information can reduce some assumptions in more complex models, but no model removes all error. Molecular, cellular and tissue descriptions are different ways of organizing the same body. Before comparing results, identify the model, measured variables and assumptions rather than treating all reported components as directly measured anatomical tissues.

For example, a local ultrasound measure at the thigh can support follow-up when site and technique are consistent. It does not independently describe whole-body muscle gain. Relate the local finding to the specific anatomical question and functional outcomes, and use further imaging only when the expected information justifies the procedure.