Usain Bolt: 'I was not at my best in 100m heats'

Usain Bolt has conceded that he was not at his best in the 100m heats at the World Athletics Championships in Beijing.

The 29-year-old had a slow start to his race, but still won with relative ease by recording a time of 9.96s to reach the semi-finals.

Bolt feels that there is plenty more to come from him in the competition as he looks to retain his world title.

"It wasn't as great as I wanted it to be, but I wasn't expecting the first one to be great," Bolt told BBC Sport.

"I wasn't trying to run fast. I wanted to save as much energy as possible. I am in wonderful shape." The Jamaican will compete in the semi-finals later today.