Usain Bolt poses for a portrait in New York June 11, 2015. Sprint supremo Bolt says he is taking his time building up to August's Beijing world championships and is looking forward to an explosive showdown there against American Justin Gatlin. REUTERS/Lucas Jackson

Jamaican sprinter Usain Bolt dances during a Jamaican-themed party, at a club in Moscow August 4, 2013. Bolt arrived in Moscow on Sunday determined to win gold at the IAAF World Championships and prove to the world that he is "still a champion". Bolt said despite the absence of some of other big-name sprinters at the competition, he was preparing for a solid perfomance at the worlds. REUTERS/Ivan Burnyashev (RUSSIA - Tags: SPORT ATHLETICS ENTERTAINMENT PROFILE) 

Jamaican sprinter Usain Bolt watches his drive as he practices at the driving range of the Slavkov u Brna golf course near the city of Brno May 29, 2011. Bolt is in the Czech Republic to attend the Golden Spike track and field meet in Ostrava on Tuesday. REUTERS/Petr Josek (CZECH REPUBLIC - Tags: SPORT ATHLETICS GOLF) 

Olympic and world sprint champion Usain Bolt of Jamaica feeds a three-month old male cheetah cub at the Kenya Wildlife Service (KWS) headquarters in Kenya's capital Nairobi November 2, 2009. Bolt adopted the cheetah cub named "Lightning Bolt" during the launch of the Animal Adoption Programme "Namayiana" at the Nairobi Animal Orphanage. REUTERS/Thomas Mukoya (KENYA ANIMALS SPORT ATHLETICS IMAGES OF THE DAY) 

Jamaican sprinter Usain Bolt drives a Ferrari "599 GTB" model during a visit at the Ferrari private track in Fiorano, northern Italy, November 15, 2010. Bolt tested models of the "458 Italia" and "599 GTB". REUTERS/Max Rossi (ITALY - Tags: SPORT ATHLETICS TRANSPORT) 

Sprinter Usain Bolt of Jamaica poses with his running spikes and official team uniform for the London 2012 Olympic Opening Ceremony during a photo shoot, arranged by his sponsors PUMA, beside a traditional routemaster bus outside the British Museum in London June 1, 2012. Bolt will defend the 100m and 200m gold medals he won in Beijing in this summer's Games. REUTERS/Dylan Martinez (BRITAIN - Tags: SPORT OLYMPICS ATHLETICS TPX IMAGES OF THE DAY)

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Jamaican Olympic gold medallist Usain Bolt falls during a footvolley match ahead of the "Mano a Mano" challenge, a 100-meter beach race, on Copacabana beach in Rio de Janeiro August 16, 2014. REUTERS/Pilar Olivares (BRAZIL - Tags: SPORT ATHLETICS) 

Olympic champion sprinters Usain Bolt (C) and Shelly-Ann Fraser-Pryce (R) look on as U.S. President Barack Obama (not pictured) participates in a town hall meeting with young Caribbean leaders at the University of the West Indies in Kingston April 9, 2015. While in Jamaica Thursday Obama also met with leaders of CARICOM, the Caribbean Community nations, before he continues on to Panama for the Summit of the Americas. REUTERS/Jonathan Ernst

Rafael Nadal (L) of Spain receives the trophy from Jamaican sprinter Usain Bolt after defeating compatriot David Ferrer in their men's singles final match to win the French Open tennis tournament at the Roland Garros stadium in Paris June 9, 2013. REUTERS/Gonzalo Fuentes (FRANCE - Tags: SPORT TENNIS SPORT ATHLETICS TPX IMAGES OF THE DAY)

Olympic champion Usain Bolt of Jamaica looks from a door before a news conference to present the Paris Areva Golden League athletics meeting in Paris July 12, 2010. REUTERS/Philippe Wojazer (FRANCE - Tags: SPORT ATHLETICS HEADSHOT) 

Sprinter Usain Bolt of Jamaica performs on stage after signing autographs at Zurich's main railway station August 27, 2009. Bolt is in Zurich to attend the IAAF Golden League athletics meeting at the Letzigrund stadium on August 28. REUTERS/Christian Hartmann (SWITZERLAND SPORT ATHLETICS ENTERTAINMENT) 

Jamaican sprinter Usain Bolt kicks the ball during a ceremonial kickoff before the Spanish first division soccer match between Real Madrid and Deportivo Coruna at Santiago Bernabeu stadium in Madrid August 29, 2009. REUTERS/Susana Vera (SPAIN SPORT SOCCER ATHLETICS) 

Usain Bolt of Jamaica covers his head with a shirt during a training session at the IAAF World Championships in Daegu, August 29, 2011. REUTERS/Lee Jae-Won (SOUTH KOREA - Tags: SPORT ATHLETICS) 

Jamaican sprinter Usain Bolt models the Jamaican team's kit for the London 2012 Olympic Games, designed by Cedella Marley, at a fashion show in London June 1, 2012. REUTERS/Paul Hackett (BRITAIN - Tags: SPORT ATHLETICS FASHION OLYMPICS) 

Usain Bolt (C) of Jamaica puts his head in his hands as he watches the netball match between Jamaica and New Zealand at the 2014 Commonwealth Games in Glasgow, Scotland, July 30, 2014. REUTERS/Phil Noble (BRITAIN - Tags: SPORT) 

Jamaica's sprinter Usain Bolt (R) looks on as the Miami Heat met the Boston Celtics during their NBA basketball game in Miami, Florida, October 30, 2012. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT BASKETBALL) 

Jamaican sprinter Usain Bolt (4) looks to make a pass during the NBA All-Star celebrity basketball game in Houston, Texas, February 15, 2013. The NBA All-Star basketball game will be played on February 17. REUTERS/Jeff Haynes (UNITED STATES - Tags: SPORT BASKETBALL ATHLETICS ENTERTAINMENT) 

Usain Bolt poses for a portrait in New York June 11, 2015. Sprint supremo Bolt says he is taking his time building up to August's Beijing world championships and is looking forward to an explosive showdown there against American Justin Gatlin. REUTERS/Lucas Jackson