Site enhancement oil, often called "santol" or "synthol" (no relation to the Synthol mouthwash brand), refers to oils injected into muscles to increase the size or change the shape. Some bodybuilders, particularly at the professional level, inject their muscles with such mixtures to mimic the appearance of developed muscle where it may otherwise be disproportionate or lacking. This is known as "fluffing". Synthol is 85% oil, 7.5% lidocaine, and 7.5% alcohol. It is not restricted, and many brands are available on the Internet. The use of injected oil to enhance muscle appearance is common among bodybuilders, despite the fact that synthol can cause pulmonary embolisms, nerve damage, infections, sclerosing lipogranuloma, stroke, and the formation of oil-filled granulomas, cysts or ulcers in the muscle. Rare cases might require surgical intervention to avoid further damage to the muscle and/or to prevent loss of life.
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.
The bulking and cutting strategy is effective because there is a well-established link between muscle hypertrophy and being in a state of positive energy balance. A sustained period of caloric surplus will allow the athlete to gain more fat-free mass than they could otherwise gain under eucaloric conditions. Some gain in fat mass is expected, which athletes seek to oxidize in a cutting period while maintaining as much lean mass as possible.
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.