Pechonkina won World Championship gold in Helsinki in 2005
Russia's Yulia Pechonkina, the current 400m hurdles world record holder, is to retire from athletics after suffering three years of health problems.
The 31-year-old, whose August 2003 time of 52.34 seconds still stands as a world best, has battled chronic sinusitis and various allergies.
After missing 2008's Beijing Olympics, Pechonkina returned to the track in July after a year out of action.
But she then pulled out of this summer's World Championships in Berlin.
Melanie Walker won the event in Pechonkina's absence, registering the second fastest time in history to come within eight hundredths of a second of the world record.
The Russian Athletics Federation reported that Pechonika made the decision a week before the World Championships after struggling to rediscover her form during training.
The Federation added that Pechonkina has opted to take a job in banking.