Hormones and Bodybuilding: Glucagon
Every athlete who does resistance exercise knows at least a little bit about hormones. The fact that testosterone and other hormones influence muscle size is nothing new. Buy now, we all know they are the agents that drive muscle development. What is new is the knowledge that you can optimize your hormonal environment to achieve greater (and faster) gains in size.
By definition a hormone is a chemical substance that is produced in one part of the body and travels by way of the bloodstream to another area where it carries out its action. Hormones are released in response to three stimuli: (a) other hormones, (b) stimulation of nerve fibers (which is what you would expect during exercise), and (c) also changes in the levels of certain nutrients in the blood.
One widely known catabolic hormone is glucagon. In this post you will find out what every bodybuilder should know about this hormone that tends to reduce the total protein mass. We strongly advise you to read our post about insulin first in order to completely understand this hormone’s mechanism of action.
When you’re trying to get bigger, you want the highest possible levels of anabolic hormones and lower levels of catabolic hormones such as glucagon. But, if you are trying to reduce body fat – that’s totally different story. During fat loss diets, elevated glucagon levels are important because it causes the burning of stored fat for fuel.
The Blood Sugar Hormones: Insulin and Glucagon
Insulin and glucagon are two hormones that are made in the pancreas. The pancreas is located in the upper abdomen, directly under the stomach. This gland weighs about 80 grams and is about 16 centimeters long. The pancreas secretes both insulin and glucagon. Both hormones are very important when fulfilling your potential as a bodybuilder.
What is Glucagon?
Glucagon is a hormone released from the pancreas when your blood sugar levels are low. Glucagon helps break down glycogen and turn it into glucose to be used for energy. Its primary function is to raise the blood glucose concentration by increasing the release of glucose from the liver and by activating gluconeogenesis, the conversion of amino acids and other small compounds such as lactic acid to glucose. Additionally, glucagon increases the breakdown of fat – helps break down adipose tissue and turns it into fatty acids to be used for energy.
What is the Difference Between Insulin and Glucagon?
Glucagon acts as an opponent to insulin. It’s often called an “insulin antagonist” because glucagon is a hormone that has the opposite task of insulin. Insulin’s job is to lower high blood sugar levels and glucagon raises low blood sugar levels. Glucagon – released from the pancreas – comes to the rescue when your blood sugar levels are low. Because there is a shortage of glucose in the blood, the body has to turn elsewhere to get it. A little saying that you can try to remember is, “When the glucose is gone, who are you gonna call? Glucagon.” Admittedly, the saying is a little corny, but sometimes those memory tricks work the best!
Like insulin, glucagon can be your best friend or your worse nightmare. Insulin promotes muscle building and fat storage, whereas glucagon promotes muscle breakdown and fat burning. If blood sugar levels are too tow (if you have not eaten for more than 3-4 hours) it mobilizes stored glycogen from the liver and releases glucose for energy. It then begins to help release stored fat into the bloodstream also to be used for energy. During fat loss diets, elevated glucagon levels are important because it causes the burning of stored fat for fuel.
Catabolic Action of Glucagon
For very low blood sugar levels (not eating for 4-5 hours or even more), glucagon also plays a part in the breakdown of muscle tissue for fuel (catabolic effect).
Glucagon’s Mechanism of Action
Glycogen is the stored form of glucose. After you eat and your pancreas releases insulin into the body, unused blood sugar (glucose) is stored in the liver and muscles as glycogen. When you haven’t eaten in a while, your insulin levels are low. The liver releases its stored glycogen into the bloodstream, re-stimulating the release of insulin so that the cells can be fed.
| INSULIN | GLUCAGON |
|---|---|
| Released in the presence of high blood glucose | Released in the presence of low blood glucose |
| Helps decrease blood sugar by sending glucose out of the bloodstream | Helps raise blood sugar by sending glucose into the bloodstream |
| Promotes muscle building and fat storage | Promotes muscle breakdown and fat burning |
| Very powerful anabolic hormone | Mild catabolic effect on protein tissue |
| Insulin promotes glycogen synthesis (increasing glycogen storage in liver) | Helps break down glycogen and turn it into glucose to be used for energy |
Effects of Insulin
- Supports the transportation of glucose and amino acids into the cells
- Stimulates the conversion from glucose into fat, resulting in a decrease of fat burning
- Helpful for supplying the cells with minerals
- Decreases glucagon secretion
Effects of Glucagon
- Stimulates the conversion from glycogen in glucose
- Increases lipolysis (the breakdown of fatty acids in the body), helps to burn body fat for energy purposes
- Decreases insulin secretion
Manipulating Glucagon Levels To Burn More Fat
The levels of the two hormones insulin and glucagon largely decide your body composition and so learning to manipulate them can result in you getting the changes to your body that you desire.
Like insulin, glucagon release is dependent on your diet, so the types and quality of the food that you eat have a significant effect on the release of insulin and glucagon.
If you wish to lose body fat, you’ll need a lower ratio of insulin. To increase glucagon and decrease insulin, eat slightly less carbohydrate and more protein. High protein meals help to increase glucagon secretion. A simple rule of thumb is to adjust your protein-to-carbohydrate ratio to between 1 to 1 and 1.5 to 1. Partition your food so that the nutrient ratio is 50 to 60 percent protein, 30 to 40 percent carbohydrate, and 10 percent fat. One problem with reducing intake of carbohydrate is the decline in energy level, but minor adjustments on a day-to-day basis will tell you what works best in your case.
You should aim to remove all sugary, fast-release carbohydrates from your diet such as sweets and fizzy drinks to prevent insulin spikes. Small increases in insulin are needed for your body to make efficient use of protein. The trick is not ingesting so many carbohydrates to spike your insulin above what is necessary to utilize nutrients effectively. When you ingest protein your body releases glucagon which largely reduces the insulin spike we previously mentioned and is hugely important for weight loss.
Lower your levels of complex carboyhydrates (such as sweet potatoes, rice, wholewheat pasta) and try to include them only around the hours that you train (before or after) to give your body the energy it needs to train intensely.
Increase your levels of healthy fats as these should be your main source of energy because they do not significantly spike insulin levels. These might come from nuts, avocados, oily fish or cold oils (such as olive oil, almond oil, coconut oil etc.)
Ensure your diet is high in fibre so that your body can adequately absorb all the nutrients. A diet high in fibre will also further slow the release of nutrients into your body, further reducing your insulin spike and maintaining a steady flow of protein to your muscles. The best sources of fibre are green veggies!
Key Terms
Glucose, glucagon, and glycogen have similar prefixes because they’re all related to the same sugar.
- Glucose – a simple sugar found in some fruit, but also broken down from white sugar or carbohydrate and absorbed into the body
- Glycogen – the stored form of glucose in the muscles and liver
- Glucagon – the hormone that stimulates the release of glycogen and stimulates the release of insulin from the pancreas
- Glycolysis – breaking down glucose into pyruvate
- Glycogenolysis – breaking down glycogen into glucose
- Lipolysis – breaking down triglycerides into glycerol and acetyl CoA (β-oxidation)
- Gluconeogenesis – making glucose from glycerol, lactate or glucogenic amino acids
- Glycogenesis – making glycogen from glucose (the synthesis of glycogen from glucose by insulin)
