How does IGF-1 promote anabolic effects in bodybuilding

IGF-1, stimulated by GH, is synthesized and secreted in the liver, and is also produced in target tissues in both autocrine and paracrine modes. How does IGF-1 promote anabolic effects in bodybuilding?

IGF-1 works by binding to the IGF-1 receptor, and before binding to the IGF-1 receptor, IGF-1 is transported to various parts of the body via IGF-binding proteins. Before we can understand how IGF-1 plays an anabolic role, we need to understand the IGF-1 receptor and IGF-binding proteins.

What is the IGF-1 receptor?

The IGF-1 receptor is a protein that exists on the surface of human cells and is activated by the IGF-1 hormone, thereby exerting anabolic effects.

IGF-1, which stands for insulin-like growth factor 1, has a similar molecular structure to insulin and therefore also binds to insulin receptors. However, its binding affinity with IGF-1 receptor is much higher than that with insulin receptor, so IGF-1 mainly binds to IGF-1 receptor and produces corresponding effects.

What are IGF-binding proteins?

Igf-binding protein is also known as IGFBP. IGF-1 has been shown to bind and interact with all seven IGFBPs (IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, IGFBP6, IGFBP7). In the human body, 99% of IGFs bind to a series of binding proteins and are then carried to various parts of the body to bind to IGF-1 receptors at various sites, thereby exerting their anabolic effects.

The availability of IGF-1 is regulated by IGFBP, and by binding to IGFBP, the half-life of IGF-1 can be extended from a few minutes to a few hours to function. Different IGFBPs can also guide IGF-1 to different tissues and bind to specific IGF-1 receptors, thereby exerting corresponding effects.

Anabolic effects of IGF-1

Almost all IGF-1 binding to IGFBP is transported to various parts of the body, binds to the corresponding IGF-1 receptors and plays anabolic roles, contributing to tissue growth and development, proliferation, lipid metabolism, pro-survival, anti-aging, anti-aging and anti-oxidation, and nerve and liver protection. The antioxidant effects of IGF-1 protect mitochondria from oxidative damage and increase ATP synthesis, providing the body with energy and motivation for exercise.