Bodybuilding has become a popular sport worldwide. Once considered only for men, it is now enjoyed by thousands of women as well. Participants in this sport combine diet and specific weight training to develop maximum muscle mass and minimum body fat, with their major goal being a well-balance, complete physique. An uninformed, untrained muscle builder can build some muscles and ignore others; the result is a disproportioned body. Skill, training, and concentration are required to build a well-proportioned, muscular body and to know which exercises build a large number of muscles and which are specialized to build certain parts of the body.

Is the old adage "no pain, no gain" correct? Not really, over-exercising can cause small tears in muscles, causing soreness. Torn muscles are weaker muscles, and it may take up to 3 weeks to repair the damage, even though the soreness may only last 5 to 10 days.

Bodybuilders concentrate on increasing skeletal muscle mass. Endurance tests conducted several years ago demonstrated that the cardiovascular and respiratory abilities of bodybuilders were similar to those abilities in normal, healthy persons, untrained in a sport. However, more recent studies indicate that the cardiorespiratory fitness of bodybuilders is similar to that of other well-trained athletes. The difference between the results of the new studies and the older studies is attributed to modern bodybuilding techniques that include aerobic exercise and running, as well as "pumping iron".

Bodybuilding has its own language. Bodybuilders refer to the "lats", "traps", and "delts" rather than the latissimus dorsi, trapezius, and deltoids. The exercises also have special names such as "lat pulldowns", "preacher curls", and "triceps extensions".

Photographs of bodybuilders are very useful in the study of anatomy to identify easily the surface anatomy of muscles that cannot be easily seen in untrained people.