SAINT-DENIS, France -- Three-time Olympian Suzy Favor Hamilton has withdrawn from the World Track and Field Championships because of a calf injury.

Hamilton, runner-up to Regina Jacobs in the women's 1,500 meters at this year's U.S. championships, notified USA Track and Field of her decision Thursday via e-mail. The event starts Saturday.

"Walking away from the championships while in the form of my life is so difficult, but the unfortunate timing of the injury leaves me little choice," she wrote.

Hamilton said she strained her lower calf 10 days ago and was advised by therapist Gerard Hartmann to pull out of the worlds.

"He feels the rounds and intensity of the championships would be too much for my calf to handle at this time," Hamilton wrote. "Though I'm extremely disappointed, I'm taking Gerard's advice because I trust his judgment, and don't want to risk further damage to the injury with an Olympic year approaching."

Hamilton, 35, is a three-time U.S. outdoor champion at 1,500 meters. The 3:57.40 clocking at the Bislett Games in 2000 is the second-fastest 1,500 by an American.

Her withdrawal leaves Jacobs, the worlds' silver medalist in 1997 and 1999, as the only U.S. woman in the 1,500.

IAAF adopts new anti-doping code
The International Association of Athletics Federations has adopted the new global anti-doping code, setting out uniform rules and sanctions for drug violations.

The IAAF already had committed itself to enacting the World Anti-Doping code during a special anti-doping summit in March. But the IAAF's congress needed to approve the code before making it binding for the sport.

IAAF secretary general Istvan Gyulai said the federation's rules need only minor changes to become fully compliant with the code. Among the provisions in the code is a two-year suspension for athletes testing positive for steroids.

All Olympic sports federations are required to enact the code before next year's Athens Games.

Money list suggested
A weekly money list detailing track and field athletes' cumulative earnings was recommended in a consultants' report presented to the IAAF on Thursday, the second and findal day of the group's biennial congress.

In one of several recommendations TSE Consulting, a firm based in London and Lausanne, said a prize list similar to those issued by the professional tennis tours should be introduced to raise the profile of athletics, particularly in the United states.

"There's a perception in the United States that athletics is an amateur sport," one of the consultants said.

IAAF president Lamine Diack said athletics could not afford to stand still if it was to remain the primary sport of the Olympic Games.

"If we are not careful, we will lose the position that we have," he said. "Athletics is facing tough competition, not only from traditional sports but also social and cultural changes.

"My hope is that athletics will find its way to the heart of the school curriculum as it was when I was young."

He also referred to the difficulties in promoting the sport in the United States and his hope that the world's premier athletics nation one day would host a world championships.

"Athletics (in the United States) is a huge sport, but outside the Olympic Games it doesn't seem to exist," he said.

Record numbers
A record 203 countries have entered the ninth world athletics championships opening Saturday, Diack said.

Diack said a total 1,902 athletes, with 1,054 men and 848 women, would take part -- including two sprinters from Afghanistan.

Prize money of $100,000 will be given to any athlete who breaks a world record.

The president of the organizing committee, Jean Dussourd, said 448,000 tickets had been sold for the nine-day championships.

"We expect to have more than 500,000 visitors to the stadium," he said.

Information from The Associated Press and Reuters was used in this report.