In men's the discus has a diameter of 22 cm and a weight of two kilograms, whereas the women's discus weighs one kilogram. To make a throw, the competitor starts in a slightly recessed concrete-surfaced circle of 2.5 metres diameter. They typically begin swinging the discus, while standing at the rear of the circle facing opposite to the direction they will throw and then rotate one and half times, before releasing the discus. The discus must land within a 40-degree arc marked by lines on the landing zone, and the competitor must not leave the circle until the discus has landed. The distance from the circle to where the discus has landed. The competitor's best throw from the allocated number of throws is recorded, and the competitor who legally throws the discus the furthest is declared the winner.
As well as achieving maximum momentum in the discus on throwing, the discus's distance is also determined by the trajectory the thrower imparts, as well as the aerodynamic behaviour of the discus.