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 metres for men and 100 metres for women. The standard long hurdle race is 400 metres 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 metres for both men and women, although races 55 meters or 50 metres long are sometimes run. A 60 metre indoor race is run over 5 hurdles. A shorter race may have only 4 hurdles. The long hurdle race is sometimes shortened to 300 metres or 200 metres, usually for indoor or high school races.
There are two basic hurdle heights: high hurdles and intermediate hurdles. The sprint hurdle races (60 m, 100 m and 110 m) use high hurdles, which are 42 inches (1.07 m) high (39 inches, or 0.99 m, in U.S. high school competition) for men and 33 inches (.84 m) high for women. Long hurdle races (400 m) use intermediate hurdles, which are 36 inches (.914 m) high for men and 30 inches (.762 m) high for women. Slightly lower heights (generally lower) are sometimes used in youth or high school events.
When approaching the first hurdle, one does not want to stutter-step (a term used to refer to the cutting of your stride length before reaching a hurdle). This cuts the runner's momentum and costs valuable time. One should attack the hurdle by launching at the hurdle from 6-7 feet away (depending on runner's closing speed.) The lead leg should be extended straight out (a slight bend can work for taller runners) so that the heel just narrowly clears the barrier's height. After launching, the trail leg is tucked in horizontally and flat, close to the side of the hip. The runner should feel as if he/she is narrowly avoiding knocking each hurdle down with his/her heel. The objective is to minimize center-of-gravity deviation from normal sprinting and reduce time spent flying through the air. All effort should be made to land light on one's feet and carry maximum momentum going to the next hurdle or finish line.
In order to properly hurdle over an obstacle and not simply jump over it, a runner must adjust his or her hips to raise them over the hurdles. Upon crossing over the hurdle barrier, the runner's lead leg should snap down quickly landing roughly 3-feet (1m) beyond the hurdle. The trail leg should drive forward at the knee (not swing - swinging causes the trunk to straighten up), and pull through to maintain stride length.
In men's hurdles it is usually necessary to straighten the leg at the top of the flight path over the hurdle, however a partial bend in the knee gains a faster push off when you hit the ground. The ability to do this will depend on the runners's leg length. As soon as the foot has cleared the hurdle, the knee starts bending again to lessen the effect of a long, slow pendulum. In women's hurdles, the lead leg is usually straight and the center of gravity does not rise relative to a normal running stride. Another way to view it is the foot path: "shortest path up and shortest path down". The opposite arm reaches farther forward and the elbow travels out to the side and then behind to make room for the trailing leg. The trailing leg also leads with the knee, but the foot and knee is horizontal, tucked up as tight as possible into the armpit.
As soon as the lead leg touches down, a strong downward push is exerted to enable the trailing leg's knee to come up under the armpit and in front of the chest. This enables recovery of some of the energy expended in the flight.
Your lead leg depends on your personal preference. Some people do not know their lead leg so the best way to determine this is to have somebody push you from behind and see what leg you step forward with. This is your lead leg. Sprint hurdlers often measure the steps between hurdles such that every hurdle is taken with the same lead leg. Distance hurdlers, however, benefit greatly if they are able to hurdle from either leg, as maintaining consistent stride lengths over the longer distances (and through the exhaustion of the longer race) is difficult.