Asafa Powell, CD is a retired Jamaican sprinter who specialised in the 100 metres. He set the 100 metres world record twice, between June 2005 and May 2008 with times of 9.77 and 9.74 seconds. Powell has consistently broken the 10-second barrier in competition, with his personal best of 9.72 s ranking fourth on the all-time list of men's 100-metre athletes. As of 1 September 2016, Powell has broken the ten-second barrier more times than anyone else—97 times. He currently holds the world record for the 100-yard dash with a time of 9.09 s, set on 27 May 2010 in Ostrava, Czech Republic. In 2016, he became Olympic champion in the 4 x 100 metres relay.
Asafa Powell at the Rio 2016 Olympics
Powell leading a heat at the 2007 World Championships in Osaka, Japan.
Powell anchoring the Jamaican relay team to a World Championship gold medal
Powell plays to the crowd at the 2010 Bislett Games
Sprinting is running over a short distance at the top-most speed of the body in a limited period of time. It is used in many sports that incorporate running, typically as a way of quickly reaching a target or goal, or avoiding or catching an opponent. Human physiology dictates that a runner's near-top speed cannot be maintained for more than 30–35 seconds due to the depletion of phosphocreatine stores in muscles, and perhaps secondarily to excessive metabolic acidosis as a result of anaerobic glycolysis.
Usain Bolt, world record holder in 100 m and 200 m sprints
This sprinter's initial crouch in the blocks allowed her to preload her muscles and channel the force generated from this into her first strides.
The stadion of ancient Nemea, Greece.
Start of the women's 60 m at the 2010 World Indoor Championships