Shot put

The shot put is a track and field event involving "throwing"/"putting" (throwing in a pushing motion) a heavy spherical object —the shot—as far as possible. The shot put competition for men has been a part of the modern Olympics since their revival in 1896, women's competition began in 1948.

History
Homer makes mention of competitions of rock throwing by soldiers during the Siege of Troy but there is no record of any dead weights being thrown in Greek competitions. The first evidence for stone- or weight-throwing events date back more than 2000 years in the Scottish Highlands. In the 16th century King Henry VIII was noted for his prowess in court competitions of weight and hammer throwing.

The first events resembling the modern shot put likely occurred in the Middle Ages when soldiers held competitions in which they hurled cannonballs. Shot put competitions were first recorded in early 19th century Scotland, and were a part of the British Amateur Championships beginning in 1866.

Competitors take their throw from inside a marked circle 2.135 m in diameter, with a stopboard about 10 cm high at the front of the circle. The distance thrown is measured from the inside of the circumference of the circle to the nearest mark made in the ground by the falling shot, with distances rounded down to the nearest centimetre under IAAF and WMA rules.

Legal throws
The following rules are adhered to for a legal throw:
 * Upon calling the athlete's name, they have sixty seconds to commence the throwing motion.
 * The athlete may not wear gloves; IAAF rules permit the taping of individual fingers.
 * The athlete must rest the shot close to the neck, and keep it tight to the neck throughout the motion.
 * The shot must be released above the height of the shoulder, using only one hand.
 * The athlete may touch the inside surface of the circle or stopboard, but must not touch the top or outside of the circle or stopboard, or the ground beyond the circle. Limbs may however extend over the lines of the circle in the air.
 * The shot must land in the legal sector (34.92°) of the throwing area.
 * The athlete must leave the throwing circle from the back.

Foul throws occur when an athlete:
 * Does not pause within the circle before beginning the throwing motion.
 * Does not begin the throwing movement within sixty seconds of having his or her name called.
 * Allows the shot to drop below his shoulder or outside the vertical plane of his shoulder during the put.
 * During the throwing motion, touches with any part of the body (including shoes):
 * the top or ends of the stop board
 * the top of the iron ring
 * anywhere outside the circle.
 * Throws a shot which either falls outside the throwing sector or touches a sector line on the initial impact.
 * Leaves the circle before the shot has landed.
 * Does not leave from the rear half of the circle.

Misconceptions
The following are either obsolete or non-existent but commonly believed rules:
 * The athlete must enter the circle from the back (none of the rule books contain such a clause).
 * The athlete entering the circle, then exiting and re-entering it prior to starting the throw results in a foul (all the rule books allow an athlete to leave a circle prior to starting a throw, but this still counts within the one minute time limit; the allowable method of exiting the circle varies by rule book).
 * Loose clothing, shoelaces, or long hair touching outside the circle during a throw, or an athlete bringing a towel into the circle and then throwing it out prior to the put results in a foul (these are no longer rules or never were rules—none of these actions provide unfair advantage to the thrower).

Competition
Shot put competitions have been held at the modern Summer Olympic Games since their inception in 1896, and it is also included as an event in the World Athletics Championships.

Each competition has a set number of rounds of throws. Typically there are three preliminary rounds to determine qualification for the final, and then three more rounds in the final. Each competitor is credited with their longest throw, regardless of whether it was achieved in the preliminary or final rounds. The competitor with the longest legal put is declared the winner.

In open competitions the men's shot weighs 7.260 kg, and the women's shot weighs 4 kg. Junior, school, and masters competitions often use different weights of shots, typically below the weights of those used in open competitions; the individual rules for each competition should be consulted in order to determine the correct weights to be used.

Putting styles
Two putting styles are in current general use by shot put competitors: the glide and the spin. With all putting styles, the goal is to release the shot with maximum forward velocity at an angle of approximately forty degrees.

Glide
The origin of the glide dates to 1951, when Parry O'Brien of the United States invented a technique that involved the putter facing backwards, rotating 180 degrees across the circle, and then tossing the shot.

With this technique, a right-hand thrower would begin facing the rear of the circle, and then kick to the front with the left leg, while pushing off forcefully with the right. As the thrower crosses the circle, the hips twist toward the front, the left arm is swung out then pulled back tight, followed by the shoulders, and they then strike in a putting motion with their right arm. The key is to move quickly across the circle with as little air under the feet as possible, hence the name "glide".

Spin
In 1972 Aleksandr Baryshnikov set his first USSR record using a new putting style, the spin ("круговой мах" in Russian), invented by his coach Viktor Alexeyev. The spin involves rotating like a discus thrower and using rotational momentum for power. In 1976 Baryshnikov went on to set a world record of 22.00 m with his spin style, and was the first shot putter to cross the 22 metre mark.

With this technique, a right-hand thrower faces the rear, and begins to spin on the ball of the left foot. The thrower comes around and faces the front of the circle and drives the right foot into the middle of the circle. Finally, the thrower reaches for the front of the circle with the left foot, twisting the hips and shoulders like in the glide, and puts the shot.

When the athlete executes the spin, the upper body is twisted hard to the right, so the imaginary lines created by the shoulders and hips are no longer parallel. This action builds up torque, and stretches the muscles, creating an involuntary elasticity in the muscles, providing extra power and momentum. When the athlete prepares to release, the left foot is firmly planted, causing the momentum and energy generated to be conserved, pushing the shot in an upward and outward direction.

Another purpose of the spin is to build up a high rotational speed, by swinging the right leg initially, then to bring all the limbs in tightly, similar to a figure skater bringing in their arms while spinning to increase their speed. Once this fast speed is achieved the shot is released, transferring the energy into the shot put.

Usage
Currently, most top male shot putters use the spin. However the glide remains popular, especially at the amateur level and among women, since the technique leads to greater consistency compared to the rotational technique. Almost all throwers start by using the glide.

It is worth noting that the world record by a male putter of 23.120 m by Randy Barnes was completed with the spin technique, while the second-best all-time put of 23.063 m by Ulf Timmermann was completed with the glide technique.

Measuring which technique can provide the most potential is difficult, as many of the best throws recorded with each technique have been completed by athletes under doping suspicions, or with a record of drug violations. The decision to glide or spin may need to be decided on an individual basis, determined by the thrower's size and power. Short throwers may benefit from the spin and taller throwers may benefit from the glide, but many throwers do not follow this guideline.

Types of shots
The shot put ball is made of different kinds of materials depending on its intended use. Materials used include iron, cast iron, solid steel, stainless steel, brass, and synthetic materials like polyvinyl. Some metals are more dense than others making the size of the shot vary, for example, indoor shots are larger than outdoor shots, so different materials are used to make them.

World records
The current world record holders are:

Continental records
The current records held on each continent are:

Note: Represents a distance set at a high altitude.

Top ten performers

 * Accurate as of June 2012

Men
