Myostatin is a hormone which at first glance seems like every bodybuilders worst nightmare. It means “Muscle stasis” and it stops muscles from growing. But it might not be as bad as you think for a few reasons
How It Works
Myostatin also known as Growth Differentiation Factor 8 (GDF8) It is part of the Tumor Growth Factor Beta family. It is encoded by the MSTN gene. It binds to the activin type II receptor on myoblasts which are like infant muscle cells and stops them from growing into full muscle cells. It also stops muscle protein synthesis. It seems to be released to stop muscles from getting too big and contradicts the actions of IGF-1. The best proven way to reduce Myostatin from being released is Creatine.
In mice with both MSTN genes disabled, the mice expressed 2 times the normal amount of muscle as normal mice.
In the Belgian Blue and Piedmontese breeds of cattle the myostatin hormone is inactive and these breeds produce 40% more muscle than other breeds of cattle.
Merely a 20% decrease in myostatin results in a dramatic increase in muscle mass. However, complete lack of myostatin results in bulls so bulky they can’t reproduce and require so much food that they are not economical for cattle farmers.
Whippets, a racing dog, were studied by the National Institute of Health (NIH). This study found there were a large percentage of the top racing dogs were heterozygous for the MSTN gene. This means that they only had one of 2 working MSTN genes. The homozygous or dogs with n0 working copies of MSTN were found to be POOR runners! They were to muscled for good performance and had other unsightly side effects like short limbs and an overbite. But were just as sweet as all the other doggies.
In humans it has been determined that if one of the genes is non functional there is an increase in muscle synthesis, if 2 are non-functional there is more muscle protein synthesis. Additionally there was on account of a toddler who lacked myostatin receptors which manifested symptoms (giant muscles) similar to a human with no myostatin. With this in mind a monoclonal antibody was developed to Myostatin. This functions like a free floating receptor which results in no effect, it is like “locks” floating in the blood that bind the “Keys” of the myostatin hormone and keep it from binding to the receptors on the muscle. These antibodies proved to be effective and resulted in a 60% increase in muscle cells, similar to the Belgian Blue and Piedmontese breeds of cattle.
Myostatin And The Heart
The heart is a muscle. Unlike skeletal muscle we don’t want our hearts getting bigger. Now although the heart produces way less myostatin than other muscles it does in fact produce myostatin. If one was to inhibit the action of myostatin it is likely the heart would keep growing. This would be bad. As the heart starts to have issues functioning it wants to get bigger to compensate for its inability to meet the demands of the body.
When the heart can’t deliver the volume of blood it needs to in a given time it is called heart failure. When the heart is failing it wants to get bigger to better meet this demand but myostatin is released and it slows or stops the heart growth. This Myostatin leaks into the blood and prevents the muscles from growing as well!
If you are less concerned with your heart then think of it this way, when your heart gets sick it hurts your gains so you have to take heart health seriously. Like wise it is possible that by inhibiting Myostatin you will have heart problems down the road which will then hurt your gains.
One More Relevant Detail
Bodybuilding is about building the best body not building the biggest body. Myostatin inhibition may lead to abdominal muscle growth even if you’re not training them. The key of the sport is having a small waist, this makes for a symmetrical and aesthetic physique. If you sacrifice this to get bigger muscles everywhere else then you’re not bodybuilding, you just mass building. If you could prevent a specific muscle from producing myostatin or block the receptors in a specific muscle that would work much better. This would allow for you to bring up weak bodyparts without growing your abdominal muscles or heart.
Nothing in this article or on this site should be considered medical advice or as an endorsement to violate any law of the country in which you reside. The information given is for fun and entertainment purposes only. All claims are 100% dependent upon proper diet and exercise. Please consult a medical practitioner prior to any diet and exercise program.