Hurdle in the context of "Soil conservation"

Hurdling is the act of jumping over an obstacle at a high speed or in a sprint. In the early 19th century, hurdlers ran at and jumped over each hurdle (sometimes known as 'burgles'), landing on both feet and checking their forward motion. Today, the dominant step patterns are the 3-step for high hurdles, 7-step for low hurdles, and 15-step for intermediate hurdles. Hurdling is a highly specialized form of obstacle racing, and is part of the sport of athletics. In hurdling events, barriers known as hurdles are set at precisely measured heights and distances. Each athlete must pass over the hurdles; passing under or intentionally knocking over hurdles will result in disqualification.

Accidental knocking over of hurdles is not cause for disqualification, but the hurdles are weighted to make doing so disadvantageous. In 1902 Spalding equipment company sold the Foster Patent Safety Hurdle, a wood hurdle. In 1923 some of the wood hurdles weighed 16 lb (7.3 kg) each. Hurdle design improvements were made in 1935, when they developed the L-shaped hurdle. With this shape, the athlete could hit the hurdle and it will tip down, clearing the athlete's path. The most prominent hurdles events are 110m for men, 100m for women, and 400m (both sexes) – these three distances are all contested at the Summer Olympics and the World Athletics Championships. The two shorter distances take place on the straight of a running track, while the 400m version covers one whole lap of a standard oval track. Events over shorter distances are also commonly held at indoor track and field events, ranging from 50m hurdles upwards. Women historically competed in the 80m hurdles at the Olympics in the mid-20th century. Hurdles race are also part of combined events contests, including the decathlon and heptathlon.

A jockey is someone who rides horses in horse racing or steeplechase racing, primarily as a profession. The word also applies to camel riders in camel racing. The word "jockey" originated from England and was used to describe the individual who rode horses in racing. They must be light, typically around a weight of 100–120 lb. (45–55 kg), and physically fit. They are typically self-employed, and are paid a small fee from the horse trainer, whose colors they wear while competing in a race. They also receive a percentage of the horse's winnings. The job has a very high risk of debilitating or life-threatening injuries, not only from racing accidents but also, because of strict weight restrictions, from eating disorders.

Originally, in most countries, the jockeys were all male. Over time, female jockeys have been allowed to ride; thus, now there are many successful and well-known female jockeys. The participation of African American jockeys has also had a complex history.