LaShawn Merritt

LaShawn Merritt (born June 27, 1986) is an American track and field athlete who competes in sprinting events, specializing in the 400 meters. He is a former Olympic champion over the distance and his personal best of 43.65 seconds makes him the sixth fastest of all time.

He was a successful junior athlete and won the 400 m gold at the 2004 World Junior Championships in Athletics, as well as setting two world junior records in the relays. He became part of the American 4×400 meter relay team and helped win the event at the 2006 IAAF World Indoor Championships. He established himself individually in 2007 by winning a silver medal in the 400  m at the 2007 World Championships.

He came out on top of a rivalry with Jeremy Wariner in 2008 by winning in the 2008 Olympic final in a personal best time, and by a record margin of 0.99 secs. He also broke the Olympic record in the relay with the American team, recording the second fastest time ever. Merritt established himself as the World Champion with a win at the 2009 World Championships in Athletics in the 400 m and the 4×400 m relay. In October 2010, he was suspended for 21 months for failing a drug test.

Usain Bolt

Usain St. Leo Bolt, OJ, CD (/ˈjuːseɪn/; born 21 August 1986) is a Jamaican sprinter. Regarded as the fastest person ever timed, he is the first man to hold both the 100 metres and 200 metres world records since fully automatic time measurements became mandatory in 1977. Along with his teammates, he also set the world record in the 4×100 metres relay. He is the reigning Olympic champion in these three events, and the first man since Leonidas of Rhodes to win six Olympic gold medals in sprinting, and an eleven-time World champion. He was the first to achieve the "double double" of winning 100 m and 200 m titles at consecutive Olympics (2008 and 2012), and topped this through the first "double triple" (including 4×100 m relays).

Although gaining worldwide popularity for a sprint double victory at the Beijing Games, Bolt has had more victories as a 200 m runner. While he had not won any significant 100 m title prior to the 2008 Olympics, he had won numerous crowns in the 200 m event at the youth, junior and senior levels. Further, at the 2013 World Championships in Moscow, Bolt completed a hat-trick of 200 m world titles by winning his third straight gold in the event. His 2009 record breaking margin for 100 m, from 9.69 seconds (his own previous world record) to 9.58, is the highest since the start of fully automatic time measurements.