This is part two of the bodybuilder's guide to protein supplements. If you missed part one, visit here.

Egg Protein (Whole, White)

The second most bioavailable form of protein, behind only whey, is egg protein. Whole egg protein is the least broken down type of egg protein, containing both the yolk and the white. It thus contains fat and cholesterol. It also contains some vitamins and minerals. Whole egg protein is slower digesting than whey, but quicker than casein.

Further breakdown of the whole egg protein by removing the yolk results in egg white protein. This type of egg protein has no fat or cholesterol, and it is absent of any vitamins and minerals. Egg white protein is digested more rapidly than whole egg protein, but at a slower rate than whey.

Beef Protein Isolate

Beef protein isolate, as the name suggests, is derived from beef. Most of the fat and cholesterol are removed, leaving a high amount of protein percentage by weight. Among the advantages of beef protein isolate is the presence of creatine and carnosine. Both of these compounds help improve 
performance in the gym. Also, beef protein isolate has a high bioavailability and is rapidly digested.

Soy Protein (Concentrate, Isolate)

Among the least bioavailable types of protein is soy, which is obtained from soy beans. However, an advantage of soy protein is the inclusion of phytochemicals, such as isoflavones, which serve as anti-oxidants in the body.

The less filtered form of soy protein is known as soy protein concentrate.

It is composed of about 70% protein by weights, with the remaining composition being made up of indigestible carbohydrates. Soy protein concentrate is digested slower than whey, but faster than casein.

When the carbs are removed from the soy protein, the resultant form is called soy protein isolate. This type of soy protein is about 90% protein by weight. There are less isoflavones in soy protein isolate than the concentrate due to the extra filtration. Soy protein isolate digests slightly quicker than soy protein concentrate.

Hemp Protein

Hemp protein is derived from hemp seeds. It contains about 50% protein by weight, making its protein content among the highest of all plants. The protein content of hemp comprises edestin and albumin, two proteins easily digested by the body.

The remaining composition of hemp protein includes the essential fatty acids omega-3 and omega-6, fiber, and several vitamins and minerals. As a result of the fatty acids and fiber, hemp protein has a slow digestion rate.

Branched-Chain Amino Acids (BCAAs)

Protein, whether it comes from whey, casein, whole eggs, etc. is made up of amino acids. There are three specific types of amino acids that are of utmost importance for bodybuilders, because they are metabolized within muscles, as opposed to the liver, which is the case for most other amino acids.

The BCAAs consist of the free form amino acids L-leucine, L-isoleucine and L-valine, none of which are produced in the body. The main function of the BCAAs is to repair muscle and other bodily tissues by promoting protein synthesis. In addition, they can be used for energy production.

L-Leucine

L-leucine is the most popular of all the free form amino acids. This is because it activates the mammalian target of rapamycin (mTOR) pathway, a regulator of protein synthesis. Another benefit of L-leucine is it helps increase growth hormone production. The GH stimulates the release of growth factors, such as insulin-like growth factor-1 (IGF-1), which repairs damaged muscle tissue.