The men's hammer throw became an Olympic event in 1900 but the women's event – using a 4 kg (8.82 lb) weight – was not widely competed until much later, finally featuring on the women's Olympic programme in 2000. The distances thrown by male athletes became greater from the 1950s onwards as a result of improved equipment using the denser metals, a switch to concrete throwing areas, and more advanced training techniques. Professional hammer throwers were historically large, strong, sturdy athletes. However, qualities such as refined technique, speed and flexibility have become increasingly important in the modern era as the legal throwing area has been reduced from 90 to 34.92 degrees and throwing technique involves three to four controlled rotations.