Why Is Whey Protein Good For Building Muscle?

Despite what advertisements suggest, drinking whey protein won't give you bulging pecs or ripped abs. Only rigorous exercise coupled with the right diet helps achieve that look. Whey protein can help, though. Unlike most aggressively hyped ergonomic supplements, whey protein is backed by scientific evidence that it can aid your weight-resistance routine. According to "The Proceedings of the Nutrition Society," whey is superior to other proteins for increasing muscle protein synthesis and growth. Whey also supports post-exercise muscle recovery and your immune system.

Function

Whey is high in leucine, isoleucine and valine. These branched chain amino acids, or BCAAs, constitute 35 percent of the essential amino acids in muscle protein.

During exercise, your body increases metabolism of BCAAs to provide energy. Eventually, that strenuous exercise can deplete the BCAAs in the muscles. A scoop of whey contains about 4 g of BCAAs, and can benefit your muscles before and after a weight-resistance routine. A study in "The American Journal of Physiology" showed that 4 to 5 g of BCAAs before exercising can significantly reduce muscle catabolism, or breakdown.

BCAAs can also help synthesize muscle protein. A study in "The American Journal of Clinical Nutrition" concluded that leucine, consumed post-exercise along with sufficient protein and carbohydrates, improves whole-body protein balance and increases muscle protein synthesis. BCAAs can also help you recover after a strenuous workout. A study in "The Journal of Nutrition" showed that supplementing with BCAAs prior to squats can help decrease post-exercise muscle soreness and fatigue for several days.

Effects

Biological value, or BV, measures how much protein the body absorbs and incorporates. Whey rates highest on several scores, proving its high bioavailabilty for muscle recovery and synthesis. Scientists use several complex formulas to determine BV. One, called percentage utilization, gave whey a 96, while eggs -- the gold standard of food protein -- earned a 94. Whey also surpassed egg protein, with 104 versus 100, on another BV measure called relative utilization.

Keep in mind that heat, chemicals and processing can denature, or damage, whey and reduce its BV. Look for a brand that says "non-denatured whey protein" to assure you're receiving the protein's full biological activity.

Lactokinins

Lactokinins, a breakdown product of whey, can aid muscle growth while also lowering blood pressure. A study at the University of Limerick showed major whey protein fractions, such as beta-lactoglobulin and bovine serum albumin, help inhibit angiotensin-converting-enzyme, or ACE, which constricts blood vessels.

Because lactokinins help your blood vessels become more dilated, nutrients can access muscles more easily for effective growth and repair.

Stronger Immune System

A cold can seriously curtail your gym routine. Whey contains protein fractions and antioxidants that can boost your immune system. Glutathione, often called the master antioxidant, destroys free radicals. Your liver and white blood cells use glutathione to detoxify potential carcinogens and other harmful substances. Glutathione also helps enhance proliferation of lymphocytes, the white blood cells that make up your immune system.

Glutathione is a tripeptide, with three amino acids linked together, in this case, cysteine, glutamic acid and glycine. All of these amino acids are abundant in whey, providing your body the necessary building blocks to make this important antioxidant. Other immune-boosting components of whey protein include immunoglobulins, lactoferrin, beta-lactoglobulin and alpha-lactalbulin.

Considerations

You're most likely to get these benefits from a professional-brand whey protein. These are sold through nutritionists and doctors only, and are superior to the chemical-saturated products you often find in mega-marts and supplement chain stores. Many commercial powders contain artificial sweeteners, colors and flavorings. Unflavored whey typically contains the least of these potentially harmful additives. Your best bet is a high-quality whey protein with as few ingredients as possible. And if you can't pronounce them, put it back on the shelf.