STOCKHOLM - Former Olympic and world heptathlon champion Carolina Kluft brought her career to an end on Saturday, claiming her body could not take the strain any longer. The 29-year-old Swede was an Olympic gold medallist at Athens in 2004, and world champion in 2003, 2005 and 2007, but she had already intended to bring down the curtain after injury prevented her from taking part in the London Olympics.