Weight training aims to build muscle by prompting two different types of hypertrophy: sarcoplasmic and myofibrillar. Sarcoplasmic hypertrophy leads to larger muscles and so is favored by bodybuilders more than myofibrillar hypertrophy, which builds athletic strength. Sarcoplasmic hypertrophy is triggered by increasing repetitions, whereas myofibrillar hypertrophy is triggered by lifting heavier weight. In either case, there is an increase in both size and strength of the muscles (compared to what happens if that same individual does not lift weights at all), however, the emphasis is different.
^ Mangano, Kelsey M.; Sahni, Shivani; Kiel, Douglas P.; Tucker, Katherine L.; Dufour, Alyssa B.; Hannan, Marian T. (February 8, 2017). "Dietary protein is associated with musculoskeletal health independently of dietary pattern: the Framingham Third Generation Study". The American Journal of Clinical Nutrition. 105 (3): 714–722. doi:10.3945/ajcn.116.136762. PMC 5320406. PMID 28179224 – via ajcn.nutrition.org.
An article by Muscle & Fitness magazine, "Overtrain for Big Gains", claimed that overtraining for a brief period can be beneficial. Overtraining can be used advantageously, as when a bodybuilder is purposely overtrained for a brief period of time to super compensate during a regeneration phase. These are known as "shock micro-cycles" and were a key training technique used by Soviet athletes.
Sandow organized the first bodybuilding contest on September 14, 1901, called the "Great Competition". It was held at the Royal Albert Hall in London. Judged by Sandow, Sir Charles Lawes, and Sir Arthur Conan Doyle, the contest was a great success and many bodybuilding enthusiasts were turned away due to the overwhelming amount of audience members. The trophy presented to the winner was a gold statue of Sandow sculpted by Frederick Pomeroy. The winner was William L. Murray of Nottingham. The silver Sandow trophy was presented to second-place winner D. Cooper. The bronze Sandow trophy — now the most famous of all — was presented to third-place winner A.C. Smythe. In 1950, this same bronze trophy was presented to Steve Reeves for winning the inaugural NABBA Mr. Universe contest. It would not resurface again until 1977 when the winner of the IFBB Mr. Olympia contest, Frank Zane, was presented with a replica of the bronze trophy. Since then, Mr. Olympia winners have been consistently awarded a replica of the bronze Sandow.
Contrary to certain rumors that animal-based protein is more suitable to trigger muscle growth than plant-based protein, a study by Mangano et al. (2017) could not provide any evidence for this. In contrast, if combined properly, plant-based protein can even have a higher biological quality. A combination of one part wheat protein (e.g. seitan) and two parts soy protein (e.g. tofu) has thus been favored by many bodybuilders. Some bodybuilders, such as Patrik Baboumian and Robert Cheeke, follow a strict vegan diet.
Some bodybuilders use drugs such as anabolic steroids and precursor substances such as prohormones to increase muscle hypertrophy. Anabolic steroids cause hypertrophy of both types (I and II) of muscle fibers, likely caused by an increased synthesis of muscle proteins. They also provoke undesired side effects including hepatotoxicity, gynecomastia, acne, the early onset of male pattern baldness and a decline in the body's own testosterone production, which can cause testicular atrophy. Other performance-enhancing substances used by competitive bodybuilders include human growth hormone (HGH), which can cause acromegaly.
Intensive weight training causes micro-tears to the muscles being trained; this is generally known as microtrauma. These micro-tears in the muscle contribute to the soreness felt after exercise, called delayed onset muscle soreness (DOMS). It is the repair of these micro-traumas that results in muscle growth. Normally, this soreness becomes most apparent a day or two after a workout. However, as muscles become adapted to the exercises, soreness tends to decrease.
In 1990, professional wrestling promoter Vince McMahon announced that he was forming a new bodybuilding organization named the World Bodybuilding Federation (WBF). McMahon wanted to bring WWF-style showmanship and bigger prize money to the sport of bodybuilding. A number of IFBB stars were recruited but the roster was never very large and featured the same athletes competing; the most notable winner and first WBF champion was Gary Strydom. McMahon formally dissolved the WBF in July 1992. Reasons for this reportedly included lack of income from the pay-per-view broadcasts of the contests, slow sales of the WBF's magazine Bodybuilding Lifestyles (later WBF Magazine), and the expense of paying multiple six-figure contracts while producing two TV shows and a monthly magazine.