Growth Hormone & Exercise
topic
Growth hormone (GH) is released in pulsatile bursts — primarily during slow-wave sleep and in response to high-intensity exercise — driving tissue repair, fat metabolism (lipolysis), muscle protein synthesis, bone remodeling, and IGF-1 production in the liver. High-intensity interval training and heavy resistance training produce the largest acute GH pulses of any physiological stimulus, with the magnitude of the response dependent on exercise intensity, lactate production, and exercise volume — making anaerobic threshold training the most potent non-pharmacological GH secretagogue available.
Role
Growth hormone's role in body composition, tissue repair, and metabolic health makes high-intensity exercise (not just any exercise) an important endocrine management tool — particularly for adults experiencing the natural GH decline of aging (GH secretion falls approximately 14% per decade after peak), who can substantially compensate for this decline through the intense exercise-induced GH pulse that is available from sprinting, heavy lifting, and HIIT but not from low-intensity continuous exercise. Most adults who are physically active but exclusively perform low-intensity continuous exercise are receiving cardiovascular benefits without the hormonal benefits that require exercise intensity above the lactate threshold.