Olympic legend Carl Lewis has cast doubt on sprint sensation Usain Bolt repeating as 100 metres champion at the London Olympics starting later this month.
Jamaican Bolt will start the July 27th to August 12 as the defending champion in both sprints after dominating in Beijing four years ago.
Lewis, who won gold in the event at the 1984 Los Angeles showpiece and four years later in Seoul, said it was difficult for sprinters to remain in peak condition for extended periods.
"The reason it hasn't been done is because it's hard to stay at that level for a long period of time. People are always trying to beat you when you are a champion," the American pointed out.
"(Yohan) Blake has beaten Bolt two years in a row now after the World Championships in 2011 and we don't know what Bolt's head is like when he loses."
He continued: "It's a challenge to win two in a row but history defines greatness. You don't have greatness in your time – you are great because of history.
"We always try to predict which races are going to be great but you just don't know and that is the brilliant thing about it."
Chinks appeared in Bolt's armour two weeks ago when he was twice beaten by training partner Blake at the Jamaica National Trials.
On both occasions, Blake clocked world-leading times – 9.75 seconds in the 100m and 19.80 in the 200m – to install himself as one of the favourites in London.
Lewis, a nine-time Olympic gold medal winner, warned about the hype surrounding Blake.
"I still don't understand this Yohan Blake situation because one year ago I had never heard of him and now everyone is saying he is the greatest," Lewis said.
"But, in 2004, I went through the same thing with Maurice Greene. I said then that history defines greatness. Maurice only won bronze [in Athens] and then disappeared. That is why I let it all take place because I know how quickly it can change."
Lewis pointed out the 100m field was perhaps a lot more open than many were willing to admit.
"People are talking about Bolt but (Justin) Gatlin could win," said Lewis.
at the time — for last place at this meeting in 2011. "I've done all the work so I'm happy that I can take something like that away. I knew I had a good chance, I saw her (Montsho) look back so then I thought, 'I've got you now'," said Ohuruogu, who was disqualified from the world championships last year for a false start. Men's world champion Kirani James timed his race to perfection, surging to the front off the bend to win in 44.86. Kenyan Silas Kiplagat burst to the front off the final bend to win the men's mile in 3:52.44 after the race had been subject to two false starts, which were put down to a technical problem.