US swimming great Michael Phelps poses for a portrait at the Madison Square Boys and Girls Club in the Bronx borough of New York in this Feb 7, 2012, file photo. Phelps, 26, remains coy about how many events he will swim in London, saying he will decide the magic number on how well he performs in the lead-up to the US Olympic trials in June and July, but said he was feeling confident about his chances of claiming more Olympic gold. Carlo Allegri / Reuters