rapid that judges found it difficult to determine whether or not they had utilized any knee bend to generate additional force, something strictly prohibited in the rules. Also prohibited was "excessive layback" (leaning back too much), but it was considered too difficult to determine what degree of layback constituted a rule violation. As a result, the clean and press was discontinued as a competition lift after 1972. 1973–present Since the 1973 World Weightlifting Championships, weightlifting competitions have been biathlons of the snatch and the clean and jerk, with the 1976 Olympics being the first Olympics in this format. Women's weightlifting In 1987, women's world championship events were included for the first time in IWF's annual World Weightlifting Championships, with women such as Karyn Marshall (USA) and Cai Jun (China) amongst the winners in that first year. Yet it was not until the 2000 Olympic Games in Sydney, Australia, that women's weightlifting was incorporated into the Olympics. China's Chen Yanqing became an early star of women's weightlifting at the Olympics—as she won Olympic gold two games in a row, in 2004 and 2008. In 2011, the International Weightlifting Federation (IWF) ruled that athletes could wear a full body "unitard" under the customary weightlifting uniform. Kulsoom Abdullah became the first woman to do so at the U.S. National Championships that year, and athletes are allowed to do so at the Olympics. IWF rules previously stated that an athlete's knees and elbows must be visible so officials can determine if a lift is correctly executed. Equipment Barbell Olympic weightlifting uses a steel bar (also known as a barbell) with larger-diameter rotating sleeves on either end, holding rubber-coated weight plates of different weights. This sleeve rotation is important for the Olympic lifts, particularly the snatch and clean movements, because it drastically reduces the rotational inertia of the bar. Without sleeve rotation, the Olympic lifter faces more challenging lifts and a greater risk of injury. A men's Olympic barbell weighs 20 kg (44 lbs) with a shaft diameter of 28 mm and a length of 2200 mm, whereas a women's Olympic barbell weighs 15 kg (33 lbs) and has a shaft diameter of 25 mm with a length of 2010 mm. The distance between the sleeves, however, is the same for the men's and the women's bars at 1310 mm. The grip texture of the bar is called the knurling, and is distributed differently between