John Inverdale presents live coverage from the Alexander Stadium in Birmingham, where the National Championships - which are also doubling as the British trials for the World Championships in Berlin - are taking place. One of the highlights of the day is the men's 100m. Dwain Chambers is considered to be the favourite, but he is just one of five British male sprinters within five one hundredths of a second. It promises to be a nail-biting event, with both the semis and finals covered live. In the women's 100m, Montell Douglas and defending champion Jeanette Kwakye start as favourites. Elsewhere, the women's 400m final sees Lee McConnell defending her crown, but this time she may have to beat World and Olympic champion Christine Ohurohgu who missed 2008's event through injury. 2007 World silver medallist Nicola Sanders is also chasing selection in what promises to be a hard contested final. Commentary comes from Steve Cram, Paul Dickenson and Jonathan Edwards.