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.
In competitive bodybuilding, bodybuilders aspire to present an aesthetically pleasing body on stage. In prejudging, competitors do a series of mandatory poses: the front lat spread, rear lat spread, front double biceps, back double biceps, side chest, side triceps, Most Muscular (men only), abdominals and thighs. Each competitor also performs a personal choreographed routine to display their physique. A posedown is usually held at the end of a posing round, while judges are finishing their scoring. Bodybuilders usually spend a lot of time practising their posing in front of mirrors or under the guidance of their coach.
Muscle growth is more difficult to achieve in older adults than younger adults because of biological aging, which leads to many metabolic changes detrimental to muscle growth; for instance, by diminishing growth hormone and testosterone levels. Some recent clinical studies have shown that low-dose HGH treatment for adults with HGH deficiency changes the body composition by increasing muscle mass, decreasing fat mass, increasing bone density and muscle strength, improves cardiovascular parameters, and affects the quality of life without significant side effects.[unreliable medical source?]
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.
Sandow was so successful at flexing and posing his physique that he later created several businesses around his fame, and was among the first to market products branded with his name. He was credited with inventing and selling the first exercise equipment for the masses: machined dumbbells, spring pulleys, and tension bands. Even his image was sold by the thousands in "cabinet cards" and other prints. Sandow was a perfect "Gracilian", a standard of ideal body proportions close to those of ancient Greek and Roman statues. Men's physiques were then judged by how closely they matched these proportions.