The motor proteins actin and myosin generate the forces exerted by contracting muscles. Current recommendations suggest that bodybuilders should consume 25–30% of protein per total calorie intake to further their goal of maintaining and improving their body composition. This is a widely debated topic, with many arguing that 1 gram of protein per pound of body weight per day is ideal, some suggesting that less is sufficient, while others recommending 1.5, 2, or more. It is believed that protein needs to be consumed frequently throughout the day, especially during/after a workout, and before sleep. There is also some debate concerning the best type of protein to take. Chicken, turkey, beef, pork, fish, eggs and dairy foods are high in protein, as are some nuts, seeds, beans, and lentils. Casein or whey are often used to supplement the diet with additional protein. Whey protein is the type of protein contained in many popular brands of protein supplements and is preferred by many bodybuilders because of its high Biological Value (BV) and quick absorption rates. Whey protein also has a bigger effect than casein on insulin levels, triggering about double the amount of insulin release. That effect is somewhat overcome by combining casein and whey. Bodybuilders are usually thought to require protein with a higher BV than that of soy, which is additionally avoided due to its claimed estrogenic properties. Still, some nutrition experts believe that soy, flax seeds and many other plants that contain the weak estrogen-like compounds or phytoestrogens, can be used beneficially, as phytoestrogens compete with estrogens for receptor sites in the male body and can block its actions. This can also include some inhibition of pituitary functions while stimulating the P450 system (the system that eliminates hormones, drugs and metabolic waste product from the body) in the liver to more actively process and excrete excess estrogen. Cortisol decreases amino acid uptake by muscle, and inhibits protein synthesis.
In contrast to strongman or powerlifting competitions, where physical strength is paramount, or to Olympic weightlifting, where the main point is equally split between strength and technique, bodybuilding competitions typically emphasize condition, size, and symmetry. Different organizations emphasize particular aspects of competition, and sometimes have different categories in which to compete.
^ Burd, Nicholas A.; Yang, Yifan; Moore, Daniel R.; Tang, Jason E.; Tarnopolsky, Mark A.; Phillips, Stuart M. (2012). "Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. Micellar casein at rest and after resistance exercise in elderly men". British Journal of Nutrition. 108 (6): 958–62. doi:10.1017/S0007114511006271. PMID 22289570.
Comer has an athletic build that comes from years of martial arts and marathon training, not to mention amateur competitive bodybuilding, activities that have taken a toll on her now bandaged 40-something-year-old knees. — Quanta Magazine, "The Art of Teaching Math and Science," 16 June 2019 Teresa Giudice, who's best known as a personality on Bravo's Real Housewives of New Jersey, competed in her first bodybuilding contest Saturday. — Carly Mallenbaum, USA TODAY, "'Real Housewives' star Teresa Giudice shows off new muscles at bodybuilding competition," 10 June 2018 His first wife, Sitora Yusufiy, suggested in an interview with Time magazine, with little evidence other than his penchant for bodybuilding and mirror-gazing, that Omar Mateen could have been gay. — Tim Fitzsimons /, NBC News, "What really happened that night at Pulse," 12 June 2018 The physique competition will be held at McGlohon Theater and includes the following categories: bodybuilding, fitness, men’s physique, figure, bikini, classic physique and women’s physique. — Courtney Devores, charlotteobserver, "Your 5-minute guide to the best things to do in Charlotte | June 22-28," 21 June 2018 Fans who have been following Giudice closely on social media have watched the reality star workout in videos, but Giudice hasn't posted publicly about her first bodybuilding competition. — Carly Mallenbaum, USA TODAY, "'Real Housewives' star Teresa Giudice shows off new muscles at bodybuilding competition," 10 June 2018 Carolyn Marvin, who served as the graduate adviser for both Prosper and Nirenberg, pointed to his thesis, an autoethnography about the subculture of bodybuilding. — Josh Baugh, San Antonio Express-News, "Nirenberg knew immediately that he’d eventually marry Erika Prosper," 17 Mar. 2018 The bodybuilding competition is one of two hosted produced each year in Louisville by Kentucky Muscle promoter Brent L. Jones. — Matt Stone, The Courier-Journal, "Bodybuilders, fitness athletes go flex at 2018 KDF Derby Championships," 29 Apr. 2018 Father John Brown is basically a bodybuilding legend, having won two Mr. Universe titles and three Mr. World crowns. — Jr Radcliffe, Milwaukee Journal Sentinel, "Facts you may have missed about each Packers draft choice in 2018," 4 May 2018 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.
In the early 2000s, the IFBB was attempting to make bodybuilding an Olympic sport. It obtained full IOC membership in 2000 and was attempting to get approved as a demonstration event at the Olympics, which would hopefully lead to it being added as a full contest. This did not happen and Olympic recognition for bodybuilding remains controversial since many argue that bodybuilding is not a sport.
In recent years, the related areas of fitness and figure competition have increased in popularity, surpassing that of female bodybuilding, and have provided an alternative for women who choose not to develop the level of muscularity necessary for bodybuilding. McLish would closely resemble what is thought of today as a fitness and figure competitor, instead of what is now considered a female bodybuilder. Fitness competitions also have a gymnastic element to them. A study by the Clinical Journal of Sport Medicine found that female bodybuilders who are taking anabolic steroids are more likely to have qualified for substance dependence disorder, to have been diagnosed with a psychiatric illness, or to have a history of sexual abuse.
The winner of the annual IFBB Mr. Olympia contest is generally 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 such as Reg Park, Lee Priest, Steve Reeves, and Arnold Schwarzenegger. Winners generally go on to become professional athletes.