GLOSSARY

Apelin
Apelin comprises peptides generated from a precursor and acting through the apelin receptor. Its functions span cardiovascular, fluid-related and metabolic regulation in several tissues.

Adipose tissue sends information. Adipose tissue contains adipocytes, vascular cells and immune populations with distinct secretory contributions. Depot, energy status and inflammation influence the resulting endocrine profile. A circulating association does not establish the producing cell or prove a causal metabolic effect.

A distinction that matters. Adipose tissue is one potential source rather than the exclusive origin. Distinct peptide forms and local delivery complicate interpretation of a total circulating measurement.

Appetite is integrated. Hunger and food intake reflect endocrine signals together with neural reward, meals, sleep and environment. Low energy availability can occur at different body sizes. No single adipokine concentration can independently determine an athlete's fueling requirements.