Clare Balding introduces live coverage as the 13th FINA World Swimming Championships begin in Rome. The biannual nine-day event is the first time the best swimmers from around the globe have assembled since the 2008 Olympic Games in Beijing. Great Britain has sent a squad of 40 to compete in the championships, including double Olympic champion Rebecca Adlington and compatriot Jo Jackson who go for gold in the women's 400m freestyle. American Michael Phelps, who won a record-breaking eight gold medals in Beijing, will also be in action in Rome. The 24-year-old from Baltimore is defending the seven gold medals he won at the last World Championships held in Melbourne in 2007. Andy Jameson and Adrian Moorhouse are the commentators.