Final answer:
Growth hormone (GH) is a protein hormone that stimulates growth, protein synthesis, and tissue building, with both direct and indirect actions. It is associated with exercise in that it helps stimulate protein synthesis in skeletal muscle, contributing to muscle growth. Indirect effects are mediated by Insulin-like growth factor 1 (IGF-1), which supports tissue growth as the body responds to exercise.
Step-by-step explanation:
Purpose of Growth Hormone and its Association with Exercise
The primary purpose of growth hormone (GH) is to regulate the growth of the human body, protein synthesis, and cellular replication. Produced by the anterior pituitary gland, GH has anabolic effects, which means it promotes protein synthesis and tissue building. GH operates through direct and indirect mechanisms. With exercise, GH can stimulate protein synthesis in skeletal muscle, contributing to muscle growth and strength.
Direct mechanisms of GH include the stimulation of triglyceride breakdown and the release of fatty acids into the blood, known as lipolysis, as well as the stimulation of glycogen breakdown in the liver. In these ways, GH supports a glucose-sparing effect and increases blood glucose levels, which resemble what is seen in diabetes mellitus.
The indirect mechanism is mediated by insulin-like growth factors (IGFs), particularly Insulin-like growth factor 1 (IGF-1). IGF-1 activates osteocytes and promotes the formation of new proteins in muscle cells and bone, supporting tissue growth as the body responds to the demands of exercise.