Olympics: Rebecca Adlington underlines her Olympic credentials Published on Saturday 23 June 2012 01:25 Rebecca Adlington did not just throw down the gauntlet, she hurled it forcefully at the feet of her Olympic rivals after producing an astonishing 800 metres freestyle at the British Gas ASA National Championships in Sheffield. The double Olympic champion is in the midst of heavy training which at its height sees her plough through 70,000m a week, but this proved no barrier as she won in eight minutes 19.03 seconds, half a length ahead of Eleanor Faulkner in second. It is the second fastest time in the world this year and one only the Nova Centurion swimmer herself has bettered. Her effort at Ponds Forge eclipsed by 0.93secs her time in Barcelona earlier this month and only Adlington has gone inside 8mins 20secs this year. Given she is in such heavy training, and will be for another fortnight, it begs the question how fast she can go at the Aquatics Centre when rested and whether her own world record is in danger. The Mansfield-born swimmer said: "I can't talk! That was so painful, far more than Barcelona. It's hard when you are on your own mentally to keep tough. I felt really sore, really tired. I didn't expect to do that. I would have been happy with mid 20s. I am so shocked with that, I don't know what to think - I'm too tired to even think. Despite her form this year, Adlington fully expects surprises in London, just as she was catapulted into the public eye with her victories in Beijing. She said: "I am a lot older, I am much more experienced, I've changed as a swimmer, I've changed as a person, as a woman. I'm totally different now, I've grown up. I'm not under the illusion that there is not going to be a Becky Adlington coming out of the woodwork like there was in Beijing. I think you have to expect the unexpected at a Games: they are totally unlike any other meet and you have to treat it like that. It's not like worlds, it's not like Commonwealths, people just come out of the bag in Olympic year. It's exciting, it's interesting, I can't wait to be part of that. Warrender's Lewis Smith just missed out on a gold medal in the 400m individual medley. Local man Matthew Johnson touched in 4:18.28 with the Edinburgh 23-year-old clocking 4:18.33 for the silver medal. Euan Inglis (Edinburgh University) also claimed a bronze medal, in the 50m breaststroke. David Broady (Gloucester) won the event in 28.97 with the Scottish teenager third in 29.65. Stephanie Proud (Chester-le-Street) won the 200m backstroke and added her name to Team GB for the Olympics that start five weeks today. Her time of 2:09.40 was within the qualifying mark.