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Insulin's Role in Your Muscular Physique

When it comes to building a better physique, this hormone is vital to your success.

Insulin's Role in Your Muscular Physique

Insulin is one of the most crucial hormones around when it comes to building a better physique. It plays a role in fat and carbohydrate metabolism and is a critical player in the minutes and hours immediately following your workout. Hence, it is frequently mentioned in articles but not often explained. Here is the mini playbook on insulin.

What It Is 

Insulin is a hormone secreted by the pancreas and has a significant role in the regulation of fat and carbohydrates metabolism. Insulin enhances the uptake of glucose into skeletal muscle, liver and fat tissue.

Why It's Important

Although it is commonly thought that insulin is just a fat storage hormone or anti-catabolic hormone (both accurate), this is an overly simplistic view. Insulin also plays an important role in reducing appetite.

In addition without insulin, a lot of the processes that occur in the body will go unregulated. For instance, breakdown of muscle protein will accelerate via a process known as proteolysis. The elevated protein in the blood is then converted to glucose, a process known as gluconeogenesis, and the end result is hyperglycemia. Lypolysis (the breakdown of fat) will also go unabated resulting in excess ketones with the end result being ketoacidosis, which can be fatal if left unchecked.

So insulin's primary role is that of a regulator, not a fat storage or anti-catabolic hormone. In addition, insulin isn't really needed to transport glucose to tissues. Studies have shown that insulin actually enhances glucose uptake into cells via the transporter GLUT4. Thus, even without insulin, glucose can still get to tissues.

How It's Managed for Greater Gains

Most people know how important carbohydrate (glycogen/glucose) is to performance in the gym and overall health. Insulin sensitivity is high following exercise but GLUT4 is the major transporter responsible for exercise-induced glucose transport. As well, training is the most potent stimulus to increase skeletal muscle GLUT4 expression (turning it on).

This plays a role in insulin action and muscle glycogen storage after exercise. Furthermore, the longer you go after exercise, the more this effect decreases. This means it is probably a good idea to consume the bulk of your carbohydrates shortly after your workout. The advantage is that most of the calories consumed shortly after are partitioned favorably towards skeletal muscle, which in turn facilitates better adaptation from training. However, it does not mean you will lose muscle mass if you don’t. After all, total calories at the end of the day still takes priority over timing of nutrients. 


Kelechi Opara is a lifetime natural athlete with over 15 years experience in the fitness field. He's the creator of the iPhone/Android app Nutritionist, the revolutionary app that's transforming lives around the world. He's also an Optimum Nutrition athlete where he helps in the formulation of their supplements. In addition, he's an internationally published cover model and a former United States Marine.