The high levels of muscle growth and repair achieved by bodybuilders require a specialized diet. Generally speaking, bodybuilders require more calories than the average person of the same weight to provide the protein and energy requirements needed to support their training and increase muscle mass. In preparation of a contest, a sub-maintenance level of food energy is combined with cardiovascular exercise to lose body fat. Proteins, carbohydrates and fats are the three major macronutrients that the human body needs in order to build muscle. The ratios of calories from carbohydrates, proteins, and fats vary depending on the goals of the bodybuilder.
In natural contests, the testing protocol ranges among organizations from lie detectors to urinalysis. Penalties also range from organization to organization from suspensions to strict bans from competition. It is also important to note that natural organizations also have their own list of banned substances and it is important to refer to each organization's website for more information about which substances are banned from competition. There are many natural bodybuilding organizations; some of the larger ones include: MuscleMania, Ultimate Fitness Events (UFE), INBF/WNBF, and INBA/PNBA. These organizations either have an American or worldwide presence and are not limited to the country in which they are headquartered.
In the last week leading up to a contest, bodybuilders usually decrease their consumption of water, sodium, and carbohydrates, the former two to alter how water is retained by the body and the latter to reduce glycogen in the muscle. The day before the show, water is removed from the diet, and diuretics may be introduced, while carbohydrate loading is undertaken to increase the size of the muscles through replenishment of their glycogen. The goal is to maximize leanness and increase the visibility of veins, or "vascularity". The muscular definition and vascularity are further enhanced immediately before appearing on stage by darkening the skin through tanning products and applying oils to the skin to increase shine. Some competitors will eat sugar-rich foods to increase the visibility of their veins. A final step, called "pumping", consists in performing exercises with light weights or other kinds of low resistance (for instance two athletes can "pump" each other by holding a towel and pulling in turn), just before the contest, to fill the muscles with blood and further increase their size and density.
Bodybuilding is the use of progressive resistance exercise to control and develop one's musculature for aesthetic purposes. An individual who engages in this activity is referred to as a bodybuilder. In competitive bodybuilding, bodybuilders appear in lineups and perform specified poses (and later individual posing routines) for a panel of judges who rank the competitors based on criteria such as symmetry, muscularity, and conditioning. Bodybuilders prepare for competitions through the elimination of nonessential body fat, enhanced at the last stage by a combination of extracellular dehydration and carbohydrate loading, to achieve maximum muscular definition and vascularity, as well as tanning to accentuate the contrast of the skin under the spotlights. Bodybuilders may use anabolic steroids and other performance-enhancing drugs to build muscles.