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.
Although muscle stimulation occurs in the gym (or home gym) when lifting weights, muscle growth occurs afterward during rest periods. Without adequate rest and sleep (6 to 8 hours), muscles do not have an opportunity to recover and grow. Additionally, many athletes find that a daytime nap further increases their body's ability to recover from training and build muscles. Some bodybuilders add a massage at the end of each workout to their routine as a method of recovering.
In the modern bodybuilding industry, the term "professional" generally means a bodybuilder who has won qualifying competitions as an amateur and has earned a "pro card" from their respective organization. Professionals earn the right to compete in competitions that include monetary prizes. A pro card also prohibits the athlete from competing in federations other than the one from which they have received the pro card. Depending on the level of success, these bodybuilders may receive monetary compensation from sponsors, much like athletes in other sports.
During the 1950s, the most successful and most famous competing bodybuilders[according to whom?] were Bill Pearl, Reg Park, Leroy Colbert, and Clarence Ross. Certain bodybuilders rose to fame thanks to the relatively new medium of television, as well as cinema. The most notable[according to whom?] were Jack LaLanne, Steve Reeves, Reg Park, and Mickey Hargitay. While there were well-known gyms throughout the country during the 1950s (such as Vince's Gym in North Hollywood, California and Vic Tanny's chain gyms), there were still segments of the United States that had no "hardcore" bodybuilding gyms until the advent of Gold's Gym in the mid-1960s. Finally, the famed Muscle Beach in Santa Monica continued its popularity as the place to be for witnessing acrobatic acts, feats of strength, and the like. The movement grew more in the 1960s with increased TV and movie exposure, as bodybuilders were typecast in popular shows and movies.
The important role of nutrition in building muscle and losing fat means bodybuilders may consume a wide variety of dietary supplements. Various products are used in an attempt to augment muscle size, increase the rate of fat loss, improve joint health, increase natural testosterone production, enhance training performance and prevent potential nutrient deficiencies.