The discus throw is a field event that has been competed since the days of the ancient Greek Olympiad. The discus is a circular object held in the tips of the fingers by an athlete standing in a circle, initially facing away from the landing area or sector. The athlete quickly spins around one and half times, building momentum, before releasing the discus. The mechanics of the discus throw are intricate and are typically mastered over several years time. U.S. and international governing bodies embrace specific rules of competition for this event.
The discus should be made of solid or hollow wood or synthetic material with a metal rim encircling the discus. The top and bottom of the discus must be identical and must be smooth throughout. The center of the discus should be raised and taper to the rim. The competitive weight of the discus varies with sex and age. Per International Association of Athletic Federations rules, females of all ages and levels use a discus weighing 1 kilogram, or 2.2 pounds, while boys use a 1.5-kg, or 3.3-pound, discus. Junior men use a 1.75-kg, or 3.85-pound, discus, and a 2-kg, or 4.4-pound, discus is used by senior men and by men at the college level.
The discus is thrown from a circle measuring 2.5 meters, or 8.2 feet, in diameter. The circle has a white rim 6 mm thick. Athletes may touch the inside of the rim only. The athlete must begin each attempt from a stationary position within the circle. Once the throw is completed the athlete must exit the circle from the back half.
In the discus throw the athlete is permitted to use chalk on both hands and the discus to assist in properly gripping the implement. There should be no taping of the hand or fingers other than to cover an injury.
Dropping of the discus outside of the circle during initial swings before the turn and throw results in a foul attempt. An attempt is considered a foul if the athlete touches the top or outside of the rim during the throw. If the discus lands on or outside of the sector lines the throw is determined to be foul. The athlete should not leave the circle until the discus has touched the ground or the attempt will be foul.
The measurement of each throw is conducted immediately following the attempt. An attempt is measured from the nearest mark of the discus to the inside of the circumference of the circle.