Athletes already blood-tested

DAEGU, South Korea -- Three-quarters of the athletes at the world championships have already undergone a blood test as part of the IAAF's sweeping anti-doping program.

The IAAF says "the flow of athletes has been so strong that on the eve of the championships more than 1,400 have come forward in a welcome sign of cooperation."

Overall, 1,945 athletes will compete in the nine-day competition, which opened Saturday.

The testing to establish a blood passport for each athlete comes on top of the 500 regular tests that are usually taken at a world championships.