Heptathlete Jessica Ennis represents one of the leading hopes for team GB but injury in 2008 almost lead to her retiring from the sport altogether, forcing her to withdraw from Beijing with three stress fractures.
Her subsequent 12 month layoff lead to her most successful season in 2009 when she won Gold at the athletic World Championships with a personal best of 6,587 points, and in 2010 with a score of 6823 points in Barcelona she was the top scorer in the Heptathlon for two years running. She went on to win gold at London 2012 and is a leading contender for Rio 2016.
The World and Olympic records for the Heptathlon were set by the now deceased American Jackie Joyner Kersee who set an astonishing total of 7291 at the Olympic Games in Seoul in 1988. There has much suspicion and speculation about this record over the years and the only woman to have got close is Carolina Kluft in 2007 with 7032 points.
Find out more about some of the other stars ahead of the Olympics: