18 June 2011 Last updated at 11:12 GMT

'Hard work' still ahead for Rebecca Adlington

Rebecca Adlington says she still has much work to do for July's World Championships in Shanghai.

The double Olympic champion won both the 400m and 800m at the National Championships in Sheffield, but admits she feels tired.

Adlington has qualified for Shanghai in the 200m, 400m and 800m freestyle, topping the world rankings in the two longer distances.