Bodybuilding is the use of progressive resistance exercise to build, control, and develop one's muscles via hypertrophy. An individual who engages in this activity is referred to as a bodybuilder. It is primarily undertaken for aesthetic purposes over functional ones, distinguishing it from similar activities such as powerlifting, which focuses solely on gaining physical strength.
In professional bodybuilding, competitors appear onstage in line-ups and perform specified poses (and later individual posing routines) for a panel of judges who rank them based on conditioning, muscularity, posing, size, stage presentation, and symmetry. Bodybuilders prepare for competitions by eliminating non-essential body fat, which is enhanced at the final stage by a combination of carbohydrate loading and dehydration to achieve maximum muscle definition and vascularity; they also get heavily tanned and shave their bodies to accentuate the contrast of their skin against the stage lights.
Bodybuilding requires much time and effort to reach the desired results. A novice bodybuilder may be able to gain 8–20 pounds (4–9 kg) of muscle per year if they lift weights for seven hours per week, but muscle gains begin to slow down after the first two years to about 5–15 pounds (2–7 kg) per year. After five years, gains can decrease to as little as 3–10 pounds (1–5 kg) per year. Some bodybuilders use anabolic steroids and other performance-enhancing drugs to build muscles and recover from injuries faster, but competitions sometimes ban the use of them due to the health risks or considerations regarding fair competition. Despite some calls for drug testing to be implemented, the National Physique Committee (considered the leading bodybuilding federation) does not require testing.The winner of the annual IFBB Mr. Olympia contest is recognized as the world's top male professional bodybuilder. Since 1950, the NABBA Universe Championships have been considered the top amateur bodybuilding contests, with notable winners including Reg Park, Lee Priest, Steve Reeves, and Arnold Schwarzenegger.