Jamaica's Usain Bolt has made a strong start in his bid to retain his Olympic sprint double.

Bolt breezed through his 200m heat, less than 48 hours after taking the 100m final.

Qualification was almost a walk in the park for the fastest man in the world, who ran 20.39 seconds.

Usain is the bookies favourite to follow up on his Beijing 200m gold, becoming the first runner to win and keep the double.

Fans will find out if he can manage the feat in the final on Thursday.