Usain Bolt has admitted to feeling "a little worried" about his fitness after coasting through his 200 metre heat in Beijing on Tuesday.
Bolt beat rival Justin Gatlin in dramatic fashion in Sunday's World Championships 100m final and returned to the Bird's Nest Stadium just 48 hours later to book his place in the 200m semi-finals with a time of 20.28 seconds.
Speaking to BBC Radio 5 live after his heat, Bolt said: "The 200 metres means a lot more to me, but I'm a little worried about my fitness because I've not done many this year, but I think I am a better technical runner in this event.
"I am tired and a little bit sore, but I'm going to take another ice bath and I'll be okay."
Gatlin will also feature in Wednesday's 200m semi-finals after he won his heat in a time of 20.19secs.