Olympic weightlifting is a sport for men and women categorised by weight classes from the huge heavyweights to the small flyweights. Only two distinct lifts are performed - the clean-and-jerk and the snatch.

Weightlifting was first introduced to the Olympic Games in 1896 as a part of track and field; was left out of the 1900 Games; reappeared in 1904; and did not return to the Olympics again until 1920 when it was admitted in its own right.

Initially, Olympic weightlifting featured some event criteria that would seem unusual in the current era. One and two-handed lifts and no weight divisions are examples.

By 1932, five weight divisions had been established and three disciplines made up the competition - the press, the snatch and the clean-and-jerk. The press was discontinued in 1972, leaving the snatch and clean-and-jerk as the sport's two lifts. The women's competition was first included at the Sydney Olympics in 2000.

Technical

Men compete in eight classes from 56 kilograms (kg) to 105 kilograms and greater, and women in seven classes from 48 kilograms to 75 kilograms and greater. Kilograms are the official Olympic unit of weight. Countries are allowed two competitors in each weight class subject to Olympic qualifying standards.

The round weights attached to the bar range in size from 2.5 kilograms to 25 kilograms. These are color-coded for competitor and audience convenience. Men use barbells weighing 20kg, and women use 15kg barbells. Each bar must have two weight clasp collars of 2.5kg each.

An athlete has one minute to perform a lift, and a warning bell sounds when 30 seconds remain. Extra time is allocated when two lifts are attempted consecutively.

Three judges adjudicate and score. The acceptability of a lift is acknowledged by lights controlled from the judges’ panel - white for a positive and red for a negative. Two out of three is sufficient for the lift to be recorded as successful.

Each competitor is allowed three attempts at each lift. The heaviest weight lifted in each discipline for each person is recorded. The heaviest combination of both lifts wins the gold medal. If a tie on weight lifted occurs, the person with the lowest body weight wins.

Major players

Weightlifting is highly popular in Eastern Europe and Asia. Russia have traditionally been the strongest nation and lead the overall medals table with 39 medals but increasingly it is China who are dominating the sport, especially since women's events were introduced. At the Beijing Olympics in 2008, Chinese lifters won eight of the 15 titles available.

Bluffer's guide

The snatch can be distinguished from the clean-and-jerk by the early overhead movement. The lifter starts from the same position, ducks under the bar and throws the bar overhead while in the squat position. He or she then stands to the finish position with bar overhead.

Useless information

After Naim Suleymanoglu defected to Turkey, his country of Bulgaria demanded a $1 million to allow him to compete in the 1988 Seoul Olympics. The man known as the "Pocket Rocket" on account of him being only 4ft 11in justified the Turkish Government paying the fee when he won the first of three consecutive gold medals in the featherweight division.