Myostatin – Myostatin is a protein that was first isolated by researchers at the Johns Hopkins University in 1997.
The bone structure and length, and therefore the length if the muscle bellies. This is going to be genetically determined. Clearly, the longer the bone, the bigger the muscle can be. Another related point here is that the tendons (muscle attachments to the bone). The size of the enthesis, or the site of attachment of the tendon to bone is also a limitation to muscle mass. While tendons can adapt to exercise, the size of the enthesis doesn’t change. What this basically means is that this would restrict the attainment of unlimited muscle mass, because even if the muscles could grow, the connective tissue that supports the muscle would give out eventually.
Genetic information – We have all been taught in school that every cell in out body carries a specific genetic information in the form of DNA that is eventually translated to the proteins that we will synthesise based on that information. So, weather you will easily grow your calves but struggle to develop your pecs even though you are doing everything right – is written down in your genetic code.
Age – With age putting on muscle becomes harder and harder because of many physiological processes that occur. There are certain neural limitations that are a primary cause of muscle loss with age. What happens is a decrease in the amount of neuronal stimulation of muscle.
Cardio – vascular limitations – Another limitation to unlimited muscle mass involves the blood delivery to muscles. As muscles increase in size, there must be adequate ability to delivery oxygen and nutrients to the muscle. These are required not only for muscular contraction, but also to supply energy to the muscle. There is, however, a limit to how many new blood vessels, can be developed which will lead to a limitation. Studies have shown an inverse relationship in the size of muscle fibres and maximal oxygen uptake into the fibres (Brainum, 2017)
Myostatin – ‘myo’ refers to muscle, while ‘statin’ refers to stop. The researchers found that myostatin directly inhibits muscle growth, which explains its name. Myostatin is a myokine, which means that it’s a protein produced in muscle. Whenever you train, the production of myostatin in muscle is blocked by as much as 40%.