GLOSSARY

IGF-1 Receptor (IGF-1R) is a kinase receptor transmitting IGF-1 signals.

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.

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.

AMPK, mTOR and related pathways integrate energy, amino-acid and other information; these proteins are not circulating hormones themselves. Components have different roles and tissue-dependent responses. A brief rise in an anabolic marker is not equivalent to guaranteed muscle gain. Effective training, adequate energy and protein and recovery opportunity are needed alongside molecular signaling for real outcomes rather than judging success from pathway activation alone.