Insulin's Role in Muscle Building

When it comes to building muscle and hormones, you almost always think of testosterone. And, you wouldn’t be wrong. Testosterone is an incredibly powerful anabolic hormone in the body; however, it’s not the only hormone that plays a role in muscle building.


Today, we turn our attention to another vitally important hormone that works in tandem with testosterone to maximize muscle growth and support an anabolic environment -- INSULIN.

What is Insulin?

Insulin is a peptide hormone released from the β-cells of the pancreas when there is a rise in the body's blood sugar level, which is typically induced by consuming carbohydrates and/or protein.[1]


The hormone is primarily responsible for regulating blood sugar levels and shuttling nutrients into cells.


Generally speaking, the body seeks homeostasis for its blood sugar levels (around 100mg/dl). If it rises above this level, insulin is released to “pick up” the excess sugars and store them in one of three areas:

  • Skeletal muscle tissue (as glycogen)
  • Liver (as glycogen)
  • Fat cells


In an ideal world, glucose would only be stored as glycogen and not fat. This is one of the reasons to use a glucose disposal agent like SlinMax, to support optimal nutrient partitioning and glucose utilization and disposal.


The other good thing is that the body does not readily store carbohydrates as fat. It is an energy intensive process converting carbohydrates to fat. Specifically, the body first seeks to use glucose for its immediate energy needs -- powering all of the cells of the body.


Once immediate energy needs are met, the body then seeks to refill depleted glycogen stores in the liver and muscles.


Only once those stores are topped off will the body start the process of de novo lipogenesis where it will convert carbohydrates to fatty acids and store them in adipocytes. Again, this process is highly inefficient and requires the body to expend energy (calories) in the process.

Insulin & Muscle Building

Insulin supports muscle building in a number of ways:


For starters, insulin possesses powerful anti-catabolic activity, which stops muscle (protein) breakdown. Since muscle growth is ultimately driven by protein synthesis outpacing protein breakdown, anything that either boosts protein synthesis or reduces protein breakdown inherently supports muscle growth.


Insulin also is known to increase blood flow and amino acid delivery to muscles.[2] This helps glucose, essential amino acids (like those found in EAmino Max), creatine, and other nutrients to enter muscle cells to fuel the repair, recovery, and growth process.


Lastly, insulin increases the activity of certain enzymes (such as glycogen synthase) which trigger glycogen formation in your muscles, enhancing performance, muscle size, and recovery.[3] The faster you can recover the more frequently and more intensely you’ll be able to train!


Insulin is an incredibly powerful hormone that not only plays an important role in cardiometabolic health but the muscle building process as well. Proper sleep, nutrition, and resistance training are vital to optimizing insulin function in the body for optimal glucose utilization and disposal. If you’re looking to further support your body’s nutrient partitioning prowess, try SlinMax.


SlinMax is a comprehensive glucose utilization and disposal agent that actually helps the body take advantage of the anabolic power of insulin for greater muscle growth and fat loss.

Click here to learn more about SlinMax and how it can support recovery and growth


  1. Wilcox G. Insulin and Insulin Resistance. Clinical Biochemist Reviews. 2005;26(2):19-39.
  2. Fujita S, Rasmussen BB, Cadenas JG, Grady JJ, Volpi E. Effect of insulin on human skeletal muscle protein synthesis is modulated by insulin-induced changes in muscle blood flow and amino acid availability. American journal of physiology Endocrinology and metabolism. 2006;291(4):E745-E754. doi:10.1152/ajpendo.00271.2005.
  3. Ortmeyer HK, Bodkin NL, Hansen BC. Insulin regulates liver glycogen synthase and glycogen phosphorylase activity reciprocally in rhesus monkeys. Am J Physiol. 1997;272(1 Pt 1):E133-8.

Leave a comment

Please note, comments must be approved before they are published