Hurdling is a type of track and field race.

There are sprint hurdle races and long hurdle races. The standard sprint hurdle race is 110 meters for men and 100 meters for women. The standard long hurdle race is 400 meters for both men and women. Each of these races is run over ten hurdles and they are all Olympic events.

Other distances are sometimes run, particularly indoors. The sprint hurdle race indoors is usually 60 meters for both men and women, although races 55 meters or 50 meters long are sometimes run. A 60 meter indoor race is run over 5 hurdles. A shorter race may occasionally have only 4 hurdles. Outdoors, a long hurdle race is sometimes shortened to 300 meters for high school races over 8 hurdles (spaced distance-wise identical to the beginning of a standard 400 meter race), and 200 meter races for middle school and younger divisions over 5 hurdles (spaced in the same position as the last 5 hurdles of a standard 400 meter race). Masters age divisions also run a permutation of 300 meters with 7 hurdles (in the same position as the last 7 hurdles of a standard 400 meter race) and 200 meters with 5 (spaced the same as for the youth) for older age divisions.

Aries Merritt (born July 24, 1985) is an American hurdler who specialises in the 110 meters hurdles, and is the reigning U.S. National Indoor Champion in the 60 meter hurdles.

A native of Marietta, Georgia, he attended Joseph Wheeler High School, where he was teammates with Reggie Witherspoon.

Merritt had a successful college athletic career: in 2006 he won the NCCA Championships, was undefeated in all hurdles events that year, and he broke Willie Gault's University of Tennessee hurdles record. His victory at the NCCA Championships in 13.21 was the second fastest ever collegiate time in the United States (only Renaldo Nehemiah had run faster). He took the 110 meter hurdles gold at the 2004 World Junior Championships and finished sixth at the 2006 World Athletics Final. He reached the World Athletics Final in 2008, finishing in fourth.

In Istanbul, Merritt became world champion on the 60 meters hurdles by beating Liu Xiang and Pascal Martinot-Lagarde in 7.44.

Liu Xiang (simplified Chinese: 刘翔; traditional Chinese: 劉翔; pinyin: Liú Xiáng; born July 13, 1983 in Putuo District, Shanghai, China) is a Chinese 110 meter hurdler. Liu is an Olympic Gold medalist and World Champion. His 2004 Olympic gold medal was the first in a men's track and field event for China.

Liu is one of China's most commercially successful athletes and has emerged as a cultural icon. He is the first Chinese athlete to achieve the "triple crown" of athletics: World Record Holder, World Champion and Olympic Champion. He was the favorite to win another gold in the 110 metre hurdles at the Beijing Olympics, but much to the dismay of his fans, he had to withdraw from competition at the last moment after a false start and aggravation to a previously unrevealed injury.

In May 2001, he won at the East Asian Games in Osaka, Japan with a time of 13.42 seconds. In August 2001, he won at the Universiade in Beijing, China with a time of 13.33 seconds. He also won at the 9th National Games of the People's Republic of China that same year.

Derval O'Rourke (born May 28, 1981 in Cork, Ireland) is an Irish sprint hurdles athlete. She competes internationally in the 60 and 100 metres hurdles, and is the Irish national record holder in both events. She has participated in two Indoor World Championships and the last five "Outdoor" World Championships and the 2004, 2008 Summer Olympics.

Born in Cork, O'Rourke attended University College, Dublin (UCD) where she held a sports scholarship between 2000 and 2004. She graduated with a BA (Hons) degree from the college in 2003 and a Diploma in Business Studies from the UCD Michael Smurfit Graduate School of Business in 2005. O'Rourke is based in Dublin and is coached by Sean and Terrie Cahill. They have been involved in her coaching since October 2005

O'Rourke lists Sonia O'Sullivan and footballer Roy Keane among her sporting idols.

Derval recently completed an honors Masters in Business Management from Smurfit Business School

O'Rourke first broke 13 seconds when she finished 4th at the 2003 European Under 23 Athletics Championships in Bydgoszcz, Poland, running a national record of 12.96 seconds, missing out on a medal by just 0.01 seconds. In 2003 she competed at her first World Athletics Championships in Paris, and in 2004 competed at her first Olympic Games in Athens, on both occasions failing to make it past the heats. In 2005 O'Rourke reached the semi finals of the World Championships in Helsinki. One week later Derval O'Rourke won the Bronze medal in the 100 m Hurdles at the World University Games in Izmir, Turkey in a time of 13.02 seconds. O'Rourke was also part of the Irish 4x100 m Relay team that won Bronze.