Creatine helps build muscle and is known to enhance other muscle building processes (11;4). This is due to its ability to alter or change a number of cellular pathways which lead to new muscle development or growth. For example, creatine improves protein formation in new muscle fibers (12;56; 57;53;54). And, creatine can increase something called insulin like growth factor 1 (IGF-1), also called somatomedin C. This is a hormone similar in molecular structure to insulin. It has an anabolic effect in adults, meaning it plays a significant part in building molecules from smaller units. IGF-1 is important in the building up process of metabolism, in this case leading to the body’s ability to build and maintain muscle. So, creatine’s effect also promotes an improvement in muscle mass (12;56). What’s more, creatine supplements can increase the water content of your muscles, called cell volumization. This process can quickly increase muscle size (53;55). Furthermore, some studies show that creatine reduces levels of myostatin, a molecule which stunts muscle growth. So, lowering myostatin can accelerate muscle gain (21). In short, creatine stimulates many biological functions leading to increased muscle size and growth.
Regarding muscle mass, which deteriorates with age,creatine is considered by some to be the world’s most effective supplement for increasing this muscle and combating age related muscle loss (11;20). Studies have shown that simply supplementing with creatine for five to seven days can markedly improve or increase both muscle size and lean body weight. Keep in mind that these preliminary improvements are the result of an upsurge in water within muscle tissue (11;55). In the longer term, creating assists with muscle fibre growth. It does this by signaling key biological pathways, while also improving strength-based muscle performance (12;56; 57; 53;18).
A wide-ranging review of scientific literature showed a consistent result in studies of creatine (Cr) and muscle gain in which those subjects taking Cr gained more muscle than those in control groups, who did the same exercise, but did not take supplements (20). For instance, a study involving participants following a training regiment for six weeks while taking creatine added an extra 2 kilograms (4.4 pounds) in muscle beyond the muscle mass developed by the control group (18). This wide-ranging review went so far as to look at how well Cr effected performance when compared to other, more popular, sports supplements, and it was found that creatine was the better choice. Creatine is considered to be safer than many sports supplements. Another benefit of creatine is its relatively inexpensive cost (20).
Creatine may assist with hypothyroid related muscle wasting. Thyroid disorders are associated with increased muscle loss and muscular disorders. When the body is trying to build more muscle, it releases creatine kinase into the blood stream. After creatine (Cr) is naturally produced by the body in the liver and kidneys it enters the bloodstream and is moved to where it is needed. About 5% of creatine goes to the brain, the rest to the muscles, which have high energy demands. The presence of Cr in muscles is associated with exercise related damage. When creatine acts as a type of enzyme, called a kinase, it modifies another molecule, which accelerates ATP production, allowing for quicker healing. A study found that there is a strong correlation between low levels of thyroid hormone T3 in the blood and higher than normal levels of creatine kinase (22). This is why hypothyroidism is associated with, and sometimes tested by measuring, the amount of creatine kinase in the blood. The thyroid gland regulates the metabolism (heart rate, blood flow, rate at which food is metabolised, fat burning), and it is this metabolic activity of which creatine is a part. This fact may be why muscular disorders are associated with thyroid problems. At the moment the association is known, but the cause is not.
If you have a thyroid problem, make sure to let your healthcare provider know if you are taking creating supplements before undergoing any thyroid testing.
References for creatine found here.
