Usain Bolt seems to have a lock on his second sprint title at the world championships even before running Thursday's 200-meter final.

Yusuf Saad Kamel of Bahrain is trying for a similar feat in the 800-1,500, but needs a little more rest to get it.

Running on two hours sleep, the Kenyan-born Bahraini followed up victory in the 1,500 late Wednesday with victory and easy qualification for the semifinals in the 800.

"I did not sleep last night because I was very excited," the son of two-time 800 world champion Billy Konchellah said.

Kamel rallied to win the 1,500 ahead of Deresse Mekonnen of Ethiopia. Favorites Yuriy Borzakovskiy of Russia and Abubakere Kaki of Sudan qualified alongside him.

In the men's pole vault, it was not a question of energy but of health.

Olympic champion Steve Hooker made it to Saturday's final on a bad leg with his only jump.

"I am not sure about my appearance in the final," Hooker said. "It is just that I am not healthy."

Defending champion Brad Walker of the United States pulled out of the event before qualifying with a pelvic injury.

Health worries rarely enter the mind of the carefree Bolt.

He has already run the U.S. track team into submission before the starting gun of Thursday's final.

On the eve of the race, American champion Shawn Crawford was exuding how Bolt could clinch a second world record by slicing 0.02 seconds off the mark the Jamaican already owns.

"I really think 19.28," Crawford said.

His own ambition? 19.51 seconds.

"I'll be happy with that," Crawford said.

So, it has the looks of another gold medal to Jamaica, and a likely 3-0 lead for the Caribbean island in the battle for sprint supremacy. The final becomes little more than Bolt's race against his own record. Defending champion Tyson Gay is injured and out of the 200.

The air was hot and muggy over the Olympic Stadium on Thursday, and Bolt loves the heat. He cut through the swelter of Beijing last year on his way to three Olympic golds and as many world records.

It seems Bolt is the only one having questions whether he can break the record. He reminded everyone a foot injury had slowed his curve running early in the season.

"I really have not done the same amount of work like I did for the 100," Bolt said.

Thursday also has finals in the decathlon, 110 hurdles and the women's 400 hurdles and high jump.

A day after winning her first 800 world title amid a gender test controversy, teenager Caster Semenya was left wondering what all the fuss was about.

Semenya dominated her rivals despite revelations that she was undergoing a gender test because of wide margins of improvement and concerns she does not meet the requirements to compete as a woman.

"She said to me she doesn't see what the big deal is all about," South Africa team manager Phiwe Mlangeni-Tsholetsane said Thursday.

The 18-year-old runner's father, Jacob, dismissed the speculation.

"She is my little girl," he told the Sowetan newspaper. "I raised her and I have never doubted her gender. She is a woman and I can repeat that a million times."

The medal ceremony for the 800 is later Thursday.