^ Mann, T; Tomiyama, AJ; Westling, E; Lew, AM; Samuels, B; Chatman, J (April 2007). "Medicare's search for effective obesity treatments: diets are not the answer". The American Psychologist. 62 (3): 220–33. CiteSeerX 10.1.1.666.7484. doi:10.1037/0003-066x.62.3.220. PMID 17469900. In sum, there is little support for the notion that diets ["severely restricting one’s calorie intake"] lead to lasting weight loss or health benefits.
On January 16, 1904, the first large-scale bodybuilding competition in America took place at Madison Square Garden in New York City. The competition was promoted by Bernarr Macfadden, the father of physical culture and publisher of original bodybuilding magazines such as Health & Strength. The winner was Al Treloar, who was declared "The Most Perfectly Developed Man in the World". Treloar won a $1,000 cash prize, a substantial sum at that time. Two weeks later, Thomas Edison made a film of Treloar's posing routine. Edison had also made two films of Sandow a few years before. Those were the first three motion pictures featuring a bodybuilder. In the early 20th century, Macfadden and Charles Atlas continued to promote bodybuilding across the world. Alois P. Swoboda was an early pioneer in America.
^ 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.
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.
As chronic obstructive pulmonary disease (COPD) advances, about 35% of patients experience severe weight loss called pulmonary cachexia, including diminished muscle mass. Around 25% experience moderate to severe weight loss, and most others have some weight loss. Greater weight loss is associated with poorer prognosis. Theories about contributing factors include appetite loss related to reduced activity, additional energy required for breathing, and the difficulty of eating with dyspnea (labored breathing).
This period also saw the rise of anabolic steroids in bodybuilding and many other sports. In bodybuilding lore, this is partly attributed to the rise of "mass monsters", beginning with Arnold Schwarzenegger, Sergio Oliva, and Lou Ferrigno in the late 1960s and early 1970s, and continuing through the 1980s with Lee Haney, the 1990s with Dorian Yates, Ronnie Coleman, and Markus Rühl, and up to the present day. Bodybuilders such as Greg Kovacs attained mass and size never seen previously but were not successful at the pro level. Others were renowned for their spectacular development of a particular body part, like Tom Platz or Paul Demayo for their leg muscles. At the time of shooting Pumping Iron, Schwarzenegger (while never admitting to steroid use until long after his retirement) said that "you have to do anything you can to get the advantage in competition". He would later say that he does not regret using anything.