GLOSSARY

Sex Hormone-Binding Globulin (SHBG) binds selected sex hormones and influences free fractions.

Sex hormones function in all people, with patterns varying by biological sex, age, cycle, medicines and energy state. Free and total concentrations differ, and binding proteins affect interpretation. The reproductive axis is sensitive to insufficient energy; menstrual disruption or persistently reduced sexual function should not simply be considered normal heavy-training effects. Diagnosis requires symptoms and appropriate testing rather than comparing one number with a teammate or using an arbitrary athletic target.

Growth hormone is pulsatile and varies with sleep, food and activity; IGF-1 and its binding proteins add further layers. A brief rise in supposedly anabolic hormones after a session does not determine future muscle growth. Normal hormonal roles are not equivalent to prescribed or pharmacological exposure. For athletes, training progress, adequate intake and recovery provide more practical information than pursuing a hormone peak or interpreting one acute endocrine response as hypertrophy.

For practical use, record meal and training timing, sleep and hunger alongside actual intake and performance trends. When a marker changes, first examine measurement conditions and plausible explanations; food decisions should support adequate supply, tolerance and recovery rather than ending the assessment at one molecular signal or assuming a concentration change automatically establishes a useful intervention.

Synthesis, storage, secretion, transport and clearance are distinct processes. Blood concentration reflects entry and removal rather than directly measuring secretion; exercise-related plasma-volume changes can also affect it. Half-life depends on hormone form and method and is not identical to the duration of all effects. Comparisons therefore need sampling time, previous food and recent activity standardized or recorded rather than interpreting isolated concentration differences without context.

Hormonal axes use feedback and often pulsatile and time-dependent patterns. A rise can be compensatory and a decline temporarily adaptive, neither diagnosing disease without context. Hormone ratios depend on numerator, denominator, timing and units. Sports nutrition does not aim to maximize every hormone; the practical goal is adequate supply and appropriate physiological responses, evaluated with health and performance rather than an isolated ratio or peak.

Low energy availability means insufficient energy remains after exercise for required bodily functions; it is not synonymous with low carbohydrate or weight loss alone. Problematic exposure can affect reproductive, thyroid, bone and appetite systems with variable patterns. Restoring supply and reviewing training load are central to assessment. One normal hormone or a universal numerical cutoff cannot confirm or exclude every case, so symptoms, history and clinical evaluation must be integrated.

Hormonal imbalance is a broad description rather than a standalone diagnosis from an online symptom list. Deficiency, excess and resistance differ, and reference ranges depend on method, age and conditions. Medicines, illness, sleep and energy status also matter. Persistent symptoms need appropriate assessment to identify causes; choosing supplements or manipulating hormones from one isolated test cannot replace evidence-based evaluation or establish a universal athletic hormone target.