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.
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.
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.
Many other important bodybuilders in the early history of bodybuilding prior to 1930 include: Earle Liederman (writer of some of bodybuilding's earliest books), Zishe Breitbart, Georg Hackenschmidt, Emy Nkemena, George F. Jowett, Finn Hateral (a pioneer in the art of posing), Frank Saldo, Monte Saldo, William Bankier, Launceston Elliot, Sig Klein, Sgt. Alfred Moss, Joe Nordquist, Lionel Strongfort ("Strongfortism"), Gustav Frištenský, Ralph Parcaut (a champion wrestler who also authored an early book on "physical culture"), and Alan P. Mead (who became an impressive muscle champion despite the fact that he lost a leg in World War I). Actor Francis X. Bushman, who was a disciple of Sandow, started his career as a bodybuilder and sculptor's model before beginning his famous silent movie career.
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.