Question: Alexis Sánchez specialized in the event that is included in the athletics program at what premier event?

full_context: Document 1: Juan Morales (hurdler): Juan Morales ("Juan Morales Hechavarría;" born July 12, 1948 in Santiago de Cuba) is a former Cuban athlete who competed mainly in 110 metres hurdles. Together with Hermes Ramírez, Pablo Montes, and Enrique Figuerola he won an Olympic silver medal in 4 x 100 metres relay in Mexico City 1968. He was a prominent athlete in the American and Caribbean scene, winning the Central American and Caribbean Championships four times in a row. He was not able to compete for his fifth title as the 1975 event was cancelled due to torrential rain. Alejandro Casañas would eventually take over his role as the leading Cuban hurdler.
Document 2: Alexis Sánchez (athlete): Alexis Sánchez González (born 13 April 1971) is a retired Spanish athlete who specialised in the 110 metres hurdles and 400 metres hurdles. Before Spain he represented his native Cuba, competing at the 1991 World Championships where he reached the semifinals. He was also the 110 metres hurdles World Junior Championships silver medalist in 1990.
Document 3: Obstacle racing: Obstacle course racing (OCR) is a sport in which a competitor, traveling on foot, must overcome various physical challenges that are in the form of obstacles. Mud and trail runs are combined and the races are designed to result in mental and physical collapse. Obstacles include, but are not limited to, climbing over walls, carrying heavy objects, traversing bodies of water, crawling under barbed wire, and jumping through fire. Many obstacles are similar to those used in military training, while others are unique to obstacle racing and are employed throughout the course to test endurance, strength, speed and, dexterity. Races vary in both distance and challenge level, combining trail running, road running, and cross country running. With race venues typically in large cities, organizers encourage athletes of all types to participate. All Obstacles were introduced into Cross Country Running at Tough Guy, recorded on video 1989 - 2007. Most signature obstacles were actually created by Mr Mouse. According to the "Los Angeles Times" in 2012, the number of events—typically all-day festivals—rose rapidly. In accordance with the sub-culture's fast rate of growth, the "Obstacle Race Magazine" was launched.
Document 4: 3000 metres steeplechase: The 3000 metres steeplechase or 3000-meter steeplechase is the most common distance for the steeplechase in track and field. It is an obstacle race over the distance of the 3000 metres, which derives its name from the horse racing steeplechase.
Document 5: 400 metres: The 400 metres, or 400 metre dash, is a common sprinting event in track and field competitions. It has been featured in the athletics programme at the Summer Olympics since 1896 for men and since 1964 for women. On a standard outdoor running track, it is one lap around the track. Runners start in staggered positions and race in separate lanes for the entire course. In many countries, athletes previously competed in the 440 yard dash (402.336 m)—which is a quarter of a mile and was referred to as the 'quarter-mile'—instead of the 400 m (437.445 yards), though this distance is now obsolete. An athlete who competes in the 400 m may still be referred to as 'quarter-miler'; the distance or event might still be called the "quarter."
Document 6: 100 metres hurdles: The 100 metres hurdles, or 100-meter hurdles, is a track and field event run mainly by women (the male counterpart is the 110 metres hurdles). For the race, ten hurdles of a height of 83.8 cm are placed along a straight course of 100 m . The first hurdle is placed after a run-up of 13 metres from the starting line. The next 9 hurdles are set at a distance of 8.5 metres from each other, and the home stretch from the last hurdle to the finish line is 10.5 metres long. The hurdles are set up so that they will fall over if bumped into by the runner, but weighted so this is disadvantageous. Fallen hurdles do not count against runners provided that they do not run into them on purpose. Like the 100 metres sprint, the 100 m hurdles begins with athletes in starting blocks.
Document 7: Alex Sánchez (outfielder): Alexis Sánchez, (born August 26, 1976), is a former Major League Baseball outfielder. He played for the Milwaukee Brewers (2001–2003), the Detroit Tigers (2003–2005), the Tampa Bay Devil Rays (2005), and the San Francisco Giants (2005).
Document 8: Jorge Richardson: Jorge L. Richardson Osorio (born February 11, 1976) is a retired male track and field athlete, who competed in the sprints events during his career. He competed for his native country at the 2000 Summer Olympics, where he was eliminated in the first round of the men's 4x100 metres relay, alongside Osvaldo Nieves, Rogelio Pizarro and Félix Omar Fernández. Richardson ran the third leg in the race.
Document 9: List of international goals scored by Alexis Sánchez: List of international goals scored by Alexis Sánchez
Document 10: 110 metres hurdles: The 110 metres hurdles, or 110-meter hurdles, is a hurdling track and field event for men. It is included in the athletics programme at the Summer Olympic Games. The female counterpart is the 100 metres hurdles. As part of a racing event, ten hurdles of 1.067 metres (3.5 ft or 42 inches) in height are evenly spaced along a straight course of 110 metres. They are positioned so that they will fall over if bumped into by the runner. Fallen hurdles do not carry a fixed time penalty for the runners, but they have a significant pull-over weight which slows down the run. Like the 100 metres sprint, the 110 metres hurdles begins in the starting blocks.
Document 11: Sprint hurdles at the Olympics: The sprint hurdles at the Summer Olympics have been contested over a variety of distances at the multi-sport event. The men's 110 metres hurdles has been present on the Olympic athletics programme since the first edition in 1896. A men's 200 metres hurdles was also briefly held, from 1900 to 1904. The first women's sprint hurdling event was added to the programme at the 1932 Olympics in the form of the 80 metres hurdles. At the 1972 Games the women's distance was extended to the 100 metres hurdles, which is the current international standard.
Document 12: Colin Jackson: Colin Ray Jackson, CBE (born 18 February 1967) is a Welsh former sprint and hurdling athlete who specialised in the 110 metres hurdles. During a career in which he represented Great Britain and Wales, he won an Olympic silver medal, became world champion twice, World indoor champion once, went undefeated at the European Championships for 12 years and was a two-time Commonwealth champion. His world record of 12.91 seconds for the 110m hurdles stood for over a decade and he remains the 60 metres hurdles world record holder.
Document 13: 4 × 100 metres relay: The 4 × 100 metres relay or sprint relay is an athletics track event run in lanes over one lap of the track with four runners completing 100 metres each. The first runners must begin in the same stagger as for the individual 400 m race. A relay baton is carried by each runner and must be passed within a 20 m changeover box (usually marked by yellow lines) which extends 10 m on either side of each 100 m mark of the race. Another line is marked 10 m farther back, marking the earliest point at which the outgoing runner may begin (giving up to 10 m of acceleration before entering the passing zone).
Document 14: Javier Sotomayor: Javier Sotomayor Sanabria (] ; born October 13, 1967) is a Cuban former track and field athlete, who specialized in the high jump and is the current world record holder. The 1992 Olympic champion, he was the dominant high jumper of the 1990s; his personal best of 2.45 m (8 ft floor(((2.45)*3.28084)−(floor((2.45)*3.28084)) *12) in) makes him the only person ever to have cleared eight feet.
Document 15: 1991 Pan American Games: The 11th Pan American Games were held in Havana, Cuba from August 2 to August 18, 1991. There were 4,519 athletes from 39 countries of the PASO community, with events in 33 different sports. The main stadium was the Estadio Panamericano, a multi-use stadium in Havana that holds 50,000 people.
ground_truth: Summer Olympic Games