GLOSSARY

Adiposity describes the degree or pattern of body-fat accumulation. It may be expressed with total or regional measures and is not one uniquely defined laboratory variable.

Total fat mass and its anatomical distribution describe different features. Subcutaneous fat lies beneath the skin, visceral adipose tissue surrounds internal abdominal organs, and ectopic lipid accumulates in sites not normally serving as the main adipose depot. Regional estimates depend on the method and boundaries used. Exercise cannot be assumed to selectively remove fat from the exact body part being trained. Interpret distribution measures within a broader health assessment rather than assigning an athlete a universal desirable regional fat value.

Adipose tissue stores energy and also participates in endocrine and immune signaling. Expansion can involve enlargement of existing fat cells, formation of additional cells and changes in surrounding tissue. White, brown and beige adipocytes differ in function and thermogenic characteristics. A change in a signaling pathway does not establish a practical method to reshape body-fat distribution. The amount of adipose tissue is only one part of an athlete's health and performance picture, and extreme depletion is not a general sporting advantage.

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.