The Band of the Irish Guards plays as giant 2012 Olympic rings (C) are unveiled at Heathrow Airport's Terminal 5, west of London, on June 20, 2012. The aluminium rings are 12 metres in width and will be seen by passengers arriving at Heathrow. The 2012 London Olympics begin on July 27, 2012. Photo| AFP

The 2012 Olympic rings are unveiled on London's Tower Bridge during a photocall in east London, on June 27, 2012. AFP PHOTO / BEN STANSALL

President Mwai Kibaki presents the national flag to Mary Nakhumicha, captain of the Kenya team to the London Paralympic games at State House Nairobi on June 27, 2012.Photo| MOHAMMED AMIN.

President Mwai Kibaki talks to David Rudisha, captain of the Kenya team to the London Olympic games at State House Nairobi on June 27, 2012. Photo | MOHAMMED AMIN.

President Mwai Kibaki witth the Kenya team to the London Olympic at State House Nairobi on June 27, 2012. Photo | MOHAMMED AMIN

Mercy Njoroge (1356) leads Milka Chemos (1355, and Lydia Rotich (1358) in the 3000m steeplechase during the Olympic trials at Nyayo National Stadium on June 23 2012. Milka won the race. Photo | MOHAMMED AMIN.

Vivian Cheruiyot fields questions from the media after winning 5000m race during the Olympic trials at Nyayo National Stadium on June 23 2012. Photo | MOHAMMED AMIN.

Isaiah Kiplagat left leads an elite field in the 5000m race during the Olympic trials at the Nyayo Stadium on June 21, 2012. He won the race. Photo| MOHAMMED AMIN.

World 800m champion, David Rudisha celebrates after winning his race during the Olympic trials at Nyayo National Stadium on June 23 2012. Photo | MOHAMMED AMIN.

Pamella Jelimo (1301) in the lead on June 23, 2012 during their London Olympics qualifiers 800metres finals at Nyayo Stadium. Jelimo won the race. Photo/CHRIS OMOLLO

Hellen Obiri (1324) competes during the Athletics Kenya London Olympics qualifiers 1500m women finals at Nyayo Stadium. Obiri won the race. Photo/CHRIS OMOLLO

Hellen Obiri (1324) celebrates her win. Photo/CHRIS OMOLLO

Brimin Kipruto competes during the Athletics Kenya 3 000meters Steeplechase London Olympics qualifiers at Nyayo Stadium. Photo/MOHAMMED AMIN

David Rudisha competes during Athletics Kenya 800meters finals for London Olympics qualifiers at Nyayo Stadium. Photo/MOHAMMED AMIN

Olympic champion Brimin Kipruto jumps over the last barrier on his way to victory in the 3000m steeplechase during the Olympic trials at Nyayo National Stadium on June 23 2012. Photo | MOHAMMED AMIN.

World 800m champion David Rudisha in charge of an elite field during the Olympic trials at Nyayo National Stadium on June 23 2012.He won the race. Photo | MOHAMMED AMIN.