There are many reasons why your muscles don't grow. One main culprit is cortisol, a stress hormone produced by your body when you are under stressful situations. Yes, any type of stress, whether they are mental stress, physical stress or even emotional stress will signal to your body to increase the level of cortisol hormones.

When you exercise or especially weightlifting body building exercises, you are placing tremendous stress on your body. This in turn will cause the cortisol hormone in your body to rise to unacceptable level which may destroy your muscle tissues, bone density mass and causes weight gain especially so in abdominal fat storage.

This hormone hates your muscles and wants you to grow fat. It takes away protein from the muscles. However to be fair to this hormone, the cortisol hormone has its uses.

Cortisol is produced by the adrenal cortex and is commonly known as a stress hormone because the level of cortisol in your body rises sharply when you are under stress. This hormone plays an important role in your body's metabolic function, it facilitates cardiovascular function, carbohydrate metabolism and controls inflammation. After all, it is a steroid hormone.

As more cortisol is being produced, your muscle tissue breaks down further since the amino acids from your muscle protein is being converted into glucose for energy. This hormone also blocks new muscle tissues from growing because it interferes in protein synthesis in your muscles.

How to lower cortisol level?

?Get enough sleep ? Let your body recuperate from the day's stress and let the body rebuild its wears and tears. A lack of sleep will put your body under further stress and thus increasing cortisol levels.

?Avoid stress ? Take up yoga, read a book, take a break from whatever you are doing. Learn meditation and breathing techniques to reduce everyday stress. Take a week or so break from your exercise routine after 6-8 weeks of regular training. As your body learns how to relax, the level of cortisol hormone will fall correspondingly.

?Do not over train ? Over training is a common issue amongst athletes of all types. This is especially so in bodybuilding and weight lifting. You are already damaging your muscles when you lift weights, don't let cortisol hormones rob your muscles of the much needed proteins and preventing muscle repair and growth.

Once your body and mind is free from stress, your cortisol production will be at a healthy level and you will once again see your muscles growing again. Of course that is provided that you are doing other things required in building muscles correctly.