Great Britain's Perri Shakes-Drayton retires at 31
Perri Shakes-Drayton, who won two world medals as part of the British 4x400m quartet, has retired from athletics at the age of 31.
She ran the first leg in Daegu in 2010 as she Nicola Sanders, Christine Ohuruogu and Lee McConnell took bronze.
She helped Britain through the 2017 heats in London, before Eilidh Doyle came into the team that won silver behind the United States in the final.
"There comes a point where you've got to decide to call it a day," she said.
Individually Shakes-Drayton also won 400m gold at the European Indoor Championships in 2013 and a European bronze over the hurdles in Barcelona in 2010.
She was the third fastest in the world in the run-up to the 2013 World Championships, but finished seventh in Moscow after damaging her knee ligaments during the final.
She didn't race again for three years and was hampered by a string of further injuries.
"I have had a tough battle with injuries but I managed to come back in 2017 and get a silver medal in relay at the worlds. That was nice but now I am ready to move on," she added.
"It has taken me a long time to make this announcement because it is not something easy.
"Athletics has given me so many opportunities, I have travelled the world, I've met some great people and I've had my fair share of ups and downs.
"It's not goodbye, it is see you later because you'll be sure to see me around."