Bodybuilding is the process of developing muscle fibers through the combination of weight training, increased calorific intake, and rest.

In order to achieve extraordinary muscle growth (hypertrophy), bodybuilders focus in three main lines of action:

Firstly, the resistance weight training causes microtears to the muscles being trained - this is generally known as microtrauma. These microtears in the muscle contribute to the soreness felt after exercise, called Delayed Onset Muscle Soreness, or DOMS. It is the repair to these microtrauma that result in muscle growth (anabolism).

The growth and repair however cannot occur without the necessary building blocks. These are supplied by high quality nutrition. Bodybuilders require a very specialised diet. Generally speaking bodybuilders require an additional 500+ calories as well as their maintenance calories. The sources of these calories are roughly:

50%: Carbohydrates (with a low glycemic index value)
35%: Protein (with a high biological value)
15%: Fats (with very few saturated fats)

Bodybuilders split their food intake for the day into 5-7 meals of roughly equal nutrional content and attempt to eat at regular intervals. This interval is normally between 2-3 hours.

Having a large proportion of calories come from carbohydrates is so that the body has enough energy to deal with the rigours of training and recovery. Bodybuilders require complex carbohydrates as they release energy more slowly than simple sugars. This is important as simple sugars cause an insulin response which places the body in a state where it is likely to store additional calories as fat rather than muscle. However bodybuilders do ingest some simple sugars post-workout to replenish glycogen stores within the muscle.

It is recommend that bodybuilders receive at least 1 gram of protein per pound of bodyweight to help the body repair the damage to muscle fibres caused by weight training. These protein sources should be of a high biological value such as steak, chicken, fish and egg whites. Chicken and egg whites are often preferred due to their relatively low fat content.

Also, adequate intake of vitamins and minerals is necessary; fruits and vegetables are good sources of these. Essential fatty acids, especially omega-3s, are consumed as well.

The third component to muscle building is rest. Without quality rest and sleep the body does not have an opportunity to rebuild and repair. A good, solid eight hours of sleep a night is essential for the bodybuilder to be refreshed and ready for the next session.

Supplements can help muscle gain, although some are unproven and many are ineffective. Creatine however, is one which has been proven to help bodybuilders, although it only helps as part of a sound weight training program.

Some bodybuilders may use drugs to gain an unfair advantage over their competitors, especially in professional competitions. One such performance enhancing drug is anabolic steroids. Steroids increase levels of free testosterone, and result in muscle hypertrophy. Significant negative side-effects accompany steroid abuse, such as liver damage as well as negative feedback leading to a decline in the body's own testosterone production - which can cause testicular atrophy and possibly infertility.

A competitive sport based on the development of muscles as described above. Bodybuilders display their physiques to a panel of judges, who assign points.

Although initially a men-only sport, in the 1980s women started to compete in separate competitions, as well.

Famous bodybuilders include Arnold Schwarzenegger, Mike Mentzer, Chris Dickerson, Reg Park, Anders Graneheim and Lee Haney. Famous female bodybuilders include Lenda Murray and Corey Everson.

Not to be confused with weight training or weightlifting, where emphasis is on actual physical strength. While similar, the fields entail a different regiment of training and diet, as well as basic motivation. Bodybuilders aspire to the development and maintenance of an aesthetically pleasant (by bodybuilding standards), balanced physique, rather than exclusively on the maximum strength development.