METFORMIN AND BODYBUILDING

If you know anyone with type 2 diabetes, then you will know that metformin is the most prescribed drug to help manage this disease and its associated complications, as it has clear benefits in relation to glucose metabolism (how it’s used in the body).

Thus, you might be wondering why bodybuilders would use a drug that is designed for diabetics, and the aim of this article is to explain the reasoning behind it and outline: how metformin works within the body, its mechanisms of action, and why assisted bodybuilders might use it.

What does metformin do

Before we unpack what metformin does, it’s important to be reminded of the function of insulin, and how one can become desensitised to it (i.e. type 2 diabetes). Insulin is a hormone released by the pancreas in response to eating/food. It is involved in the transportation of glucose into cells, a process which lowers our blood sugar back down to where it was prior to eating. Importantly, insulin promotes the uptake of glucose into both muscle and fat cells.

If blood sugar levels are chronically elevated – for example, in response to continuous over-consumption of calories which can lead to obesity – the body’s cells become less responsive to insulin’s message (i.e., up-taking glucose) and thus become desensitised to its presence. As a result, glucose molecules remain in the bloodstream, which of course means that blood sugar levels are not lowered. Given that it is toxic for humans to have high levels of blood sugar, our body will subsequently store any excess as fat. This is where metformin can take action.

Firstly, metformin will lower blood sugar levels by suppressing glucose production. It does this by suppressing gluconeogenesis, which refers to the process in which our body breaks down non-carbohydrate molecules (such as protein) and turns them into glucose. Metformin blocks this process by activating a liver enzyme called AMPK, which also plays an important role in insulin signalling, whole body energy balance, and the metabolism of glucose and fat.

Secondly, metformin will improve insulin sensitivity. This can be associated with several mechanisms such as the increased recruitment of GLUT4 transporters in skeletal muscle, which oversees moving glucose in and out of cells. An increased recruitment of GLUT4 transporters will mean glucose will be more readily be moved from the blood into muscle and lower blood glucose levels.

Simultaneously, in adipose tissue, metformin will inhibit lipolysis which may indirectly improve insulin sensitivity through reduced lipotoxicity. This is a process whereby lipids are broken down and released into the blood; they then accumulate in circulation and in non-adipose tissues which can lead to insulin resistance, as is commonly seen in type 2 diabetics. It will also increase fatty acid oxidation which is the breakdown of fats to release energy. This meaning that the use of metformin we will see less accumulation of lipids in circulation and in non-adipose tissues, decreasing insulin resistance.

Thirdly, metformin will enhance glycogen synthesis, which is the process whereby glucose molecules are packed together into long chains and stored as glycogen, often in skeletal muscle and the liver. It has also been shown to decrease the absorption of glucose uptake from food in transit in the intestines.

Thus, metformin directly and indirectly improves insulin sensitivity through various mechanisms and pathways in the body.

Why would bodybuilders use this?

Now that you know a little bit more about how metformin lowers blood sugar and improves insulin sensitivity, you might be wondering why on earth assisted bodybuilders would use it.

If you have read the other content on the website, you’ll know that assisted bodybuilders must consume large amounts of food to support muscle growth; they might also be using things such as growth hormone to help with this. As such, due to high carbohydrate intake, assisted bodybuilders’ blood sugar levels can be a little higher than they would like them to be. If left unchecked, those higher blood sugars could see glucose uptake being promoted more towards fat tissue opposed to muscle tissue, in the same way that is observed in people with type 2 diabetes.

Therefore, to improve their blood sugars, some bodybuilders might use metformin, especially if they do not want to use exogenous insulin. In addition, it can serve as a counter-response to the gluconeogenesis that is caused by taking growth hormone. Gluconeogenesis is the break down of non carbohydrate pre cursors to glucose, such as protein, so will increase blood glucose levels, metformin useage may be used to counter act this as it is shown to reduce gluconeogenesis.

In addition, metformin has been shown to act as a strong antioxidant and anti-inflammatory compound. This is beneficial to assisted bodybuilders, who should be aiming to keep the levels of oxidative stress low in their bodies, as their use of anabolics will increase this. High levels of oxidative stress can damage cells, proteins and play a role in the development of many health conditions such as cancer and neurodegenerative diseases, and as such, taking something such as metformin can help reduce those negative long-term effects.

Speaking of long-term health effects, it is well documented that using anabolic steroids has a negative impact on cholesterol: specifically, it causes a reduction in high density lipoproteins (HDLs or good cholesterol), and an increase in low density lipoproteins (LDLs or bad cholesterol). Metformin can balance this out as it has the opposite effect, increasing HDLs and lowering LDLs, thus somewhat counteracting the impact of AAS.

Altogether, it can be said that metformin is used by bodybuilders as a harm reduction strategy which impacts cardiovascular risk, cancer, and neurodegenerative diseases.

Its use for female-specific issues

Metformin isn’t just something that is used by assisted bodybuilders or diabetic people. In fact, it has been shown to help support women who suffer from various sex hormone-related issues: specifically, polycystic ovarian syndrome (PCOS) and endometriosis. PCOS can negatively impact blood sugar regulation, which is why often women who suffer from this condition might find it harder to lose weight. As such, metformin can be used as a front-line treatment to not only help improve insulin sensitivity in these females, but to also increase ovulation. In endometriosis, metformin’s antioxidant and antiproliferative effects can significantly reduce flare ups and pain symptoms, and well as increase ovulation. I have worked with females suffering from both conditions, and when I mention that they can get metformin prescribed from the NHS, most are unaware of this treatment method.

Thus, the use of metformin for females with PCOS or endometriosis can improve their insulin sensitivity, leading to a more optimal blood sugars that support nutrient uptake into muscle tissue over fat tissue. From personal experience, I have also seen how taking metformin can reduce pain during endometriosis flare-ups, and I have seen it influence a client’s ability to train during this time (i.e. from not being able to move to being able to manage the pain effectively).

In summary, metformin is typically used as a medication for those who suffer from type 2 diabetes but is also used by bodybuilders. It works to lower blood sugar and improve insulin sensitivity through a variety of different mechanisms that involve the production, storage, and transportation of glucose into cells. Assisted bodybuilders might use this medication to help manage their blood sugars but also for its antioxidant and anti-inflammatory effects, as well to increase HDLs and reduce LDLs. It is also used as a front-line treatment method in females who suffer from endometriosis and PCOS to help manage their blood sugar levels, reduce pain, and increase ovulation.

Vaughan Wilson Bsc Hons

References :

https://bariatrictimes.com/insulin-resistance-and-the-use-of-metformin-effects-on-body-weight/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552828/

https://www.frontiersin.org/articles/10.3389/fendo.2020.00191/full

https://pubmed.ncbi.nlm.nih.gov/14502098/

https://www.nature.com/articles/s41598-019-42531-0

https://pubmed.ncbi.nlm.nih.gov/28865539/

https://www.sciencedirect.com/science/article/pii/S1110569012000957