Every cell in your body, muscle cells included, requires protein for the vital processes that they perform. Without it, they cannot repair, propagate, or "breathe." Complete proteins, such as those found in whole foods like chicken, fish, and others, should comprise the staple foods of bodybuilders. To supplement their protein needs, however, as bodybuilders often ingest over 100 grams of protein in a day, protein supplements are used.

With supplements added, bodybuilders fill their increased need for protein, as they are damaging their cells at a rapid rate and need extra protein to regenerate their muscle.

Two of the most common forms of protein supplements are whey protein isolate and casein. Whey protein isolate is a protein-dense substance derived from a liquid product of cheese. It contains the vital amino acids that eventually form the "complete proteins" mentioned earlier. The convenient thing about whey is that it mixes easily in water or milk and can be digested relatively easily. Whey protein shakes and bars, therefore, are extremely common supplements among bodybuilders.

Casein is derived from milk. Similar to whey, it contains amino acids for the muscles to use for fueling and repair. Casein digests much slower than whey, however, rendering it very effective for pre-workout supplementation.

Selecting the Best Protein Supplements

After selecting a protein supplement, the next step is to set up a consistent regimen. Since it is meant to supplement exercise, try to avoid having more than 3 days off while taking supplements in order to deter unwanted weight gain. As it concerns timing, the first half hour after a resistance program, also known as the "glycemic window," is ideal for protein intake. The glycemic window is a period of heightened metabolic activity in which the body is most prepared and most in need of protein. Many bodybuilders also fuel up before workouts as well. As long as workouts are consistent, most protein shakes and bars recommend 2 to 4 servings a day, at 20 to 35 grams per serving.