William Collazo is a Cuba

Cuba

The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

n sprinter who specializes in the 400 metres

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 . On a standard outdoor running track, it is exactly one lap around the track. Runners start in staggered positions and...

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He won a bronze medal in the 4 x 400 metres relay

4 x 400 metres relay

The 4 x 400 meters relay or long relay is an athletics track event in which teams comprise four runners who each complete 400 meters or one lap. It is traditionally the final event of a track meet. At top class events, the first 500 meters is run in lanes...

 at the 2005 Central American and Caribbean Championships

2005 Central American and Caribbean Championships in Athletics

The 2005 Central American and Caribbean Championships in athletics were held at the Thomas Robinson Stadium in Nassau, Bahamas, between 8–11 July 2005. Nearly 700 athletes from around 30 of the region's countries competed at the event.-Men's events:...

. He also competed at the 2007 World Championships

2007 World Championships in Athletics

The 11th World Championships in Athletics, under the auspices of the International Association of Athletics Federations , were held at Nagai Stadium in Osaka, Japan from 24 August to 2 September 2007...

, the 2008 Olympic Games

Athletics at the 2008 Summer Olympics - Men's 400 metres

-Round 1:The first round was held on 18 August. The first three runners of each heat plus the next three overall fastest runners qualified for the semifinals.-Heat 1:-Heat 2:-Heat 3:-Heat 4:-Heat 5:-Heat 6:-Heat 7:-Semifinal 1:...

 and the 2009 World Championships

2009 World Championships in Athletics

The 12th IAAF World Championships in Athletics were held in Berlin, Germany from 15–23 August 2009. The majority of events took place in the Olympiastadion, while the marathon and racewalking events started and finished at the Brandenburg Gate....

, but without reaching the final round.

His personal best time is 44.93 seconds, achieved at the World Championships in August 2009 in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

. He also has 21.27 seconds in the 200 metres

200 metres

A 200 metres race is a sprint running event. On an outdoor 400 m track, the race begins on the curve and ends on the home straight, so a combination of techniques are needed to successfully run the race. A slightly shorter race, called the stadion and run on a straight track, was the first...

, achieved in March 2004 in Havana

Havana

Havana is the capital city, province, major port, and leading commercial centre of Cuba. The city proper has a population of 2.1 million inhabitants, and it spans a total of — making it the largest city in the Caribbean region, and the most populous...

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Achievements

Representing
2008	Ibero-American Championships 2008 Ibero-American Championships The 2008 Ibero-American Championships in Athletics was an athletics competition which was held at the Estadio Tierra de Campeones in Iquique, Chile from 13–15 June...	Iquique Iquique Iquique is a port city and commune in northern Chile, capital of both the Iquique Province and Tarapacá Region. It lies on the Pacific coast, west of the Atacama Desert and the Pampa del Tamarugal. It had a population of 216,419 as of the 2002 census... , Chile Chile Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...	1st	4x400 m relay	3:03.22
2009	Central American and Caribbean Championships 2009 Central American and Caribbean Championships in Athletics The 2009 Central American and Caribbean Championships was the twenty second edition of the tournament and was held between 3 and 7 July in Havana, Cuba.-Event summary:...	Havana, Cuba	1st	400 m
			1st	4x400 m relay
2010	World Indoor Championships	Doha, Qatar	2nd	400 m
	Ibero-American Championships 2010 Ibero-American Championships The 2010 Ibero-American Championships in Athletics was an athletics competition which was held at the Estadio Municipal Bahía Sur in San Fernando, Cádiz, Spain from 4–6 June. A total of 44 events were contested, of which 22 by male and 22 by female athletes...	San Fernando, Spain San Fernando, Spain -External links:* - Sistema de Información Multiterritorial de Andalucía...	1st	4x400 m relay	3:04.86 2010 Ibero-American Championships The 2010 Ibero-American Championships in Athletics was an athletics competition which was held at the Estadio Municipal Bahía Sur in San Fernando, Cádiz, Spain from 4–6 June. A total of 44 events were contested, of which 22 by male and 22 by female athletes...
			2nd	400 m	45.33
2011	Pan American Games Athletics at the 2011 Pan American Games Athletics competitions at the 2011 Pan American Games in Guadalajara was held from October 23 to October 30 at the newly built Telmex Athletics Stadium. The racewalking and marathon events were held on the temporary Guadalajara Circuit and Route and the Pan American Marathon circuit respectively...	Guadalajara, Mexico	1st	4x400 m relay	2:59.43 Athletics at the 2011 Pan American Games – Men's 4 × 400 metres relay The men's 4 x 400 metres relay competition of the athletics events at the 2011 Pan American Games took place on the 27 and 28th October at the Telmex Athletics Stadium...